Method and apparatus for substrate polishing

Method and equipment based on grinding

<p>L00. . . Processing tank</p><p>L04. . . plate</p><p>108. . . Substrate</p><p>L14. . . Cover</p><p>1l8. . . Port</p><p>L22. . . Abrasive pad assembly</p><p>L24. . . power supply</p><p>L28. . . Undertaking</p><p>132. . . Conveyor system</p><p>L36. . . Drive System</p><p>142. . . Electrolyte supply</p><p>L46. . . Side wall</p><p>152. . . Arm</p><p>156. . . axis</p><p>202. . . Conductive pad</p><p>206. . . electrode</p><p>2l0. . . Second side</p><p>214. . . First side</p><p>218. . . Opening</p><p>222. . . Second side</p><p>262. Conductive component</p><p>300. . . Abrasive pad assembly</p><p>L02. . . Grinding head</p><p>L06. . . Base</p><p>L10. . . Drive System</p><p>1l6. . . bag</p><p>120. . . valve</p><p>122A, 122B. . . wire</p><p>L26. . . Slip ring</p><p>130. . . Export</p><p>L34. . . Bearing</p><p>138. . . Buckle</p><p>144. . . bottom</p><p>150. . . Processing device</p><p>L54. . . pillar</p><p>L58. . . Processing component</p><p>204. . . pad</p><p>208. . . First side</p><p>212. . . Opening</p><p>2l6. . . Second side</p><p>220. . . First side</p><p>260. . . Dielectric pad body</p><p>264. . . groove</p><p>302. . . Conductive pad</p><p>304. . . pad</p><p>3l0. . . Abrasive pad assembly</p><p>3l4. . . electrode</p><p>400. . . Processing tank</p><p>404. . . Second electrode</p><p>408. . . Abrasive pad assembly</p><p>412. . . bottom</p><p>418. . . power supply</p><p>422. . . Second surface</p><p>426. . . Second opening</p><p>432. . . pad</p><p>452, 454. . . Outer edge</p><p>460, 462. . . Electrochemical battery</p><p>502. . . Processing tank</p><p>508. . . Bearing</p><p>5l2. . . Grinding head</p><p>552. . . support</p><p>556. . . Cantilever</p><p>560. . . Device board</p><p>600. . . Grinding system</p><p>604. . . Grinding station</p><p>608. . . Substrate transfer mechanism</p><p>6l2. . . Abrasive material</p><p>622. . . Rotary rack</p><p>306. . . electrode</p><p>3l2. . . pad</p><p>316, 3l8. . . Opening</p><p>402. . . First electrode</p><p>406. . . plate</p><p>410. . . Side wall</p><p>4l4, 416. . . wire</p><p>420. . . Abrasive surface</p><p>424. . . First opening</p><p>430. . . Dielectric body</p><p>440. . . Slip ring</p><p>456, 458. . . Inner edge</p><p>500. . . Grinding system</p><p>506. . . Disk assembly</p><p>5l0. . . Grinding head assembly</p><p>520. . . Cantilever actuator</p><p>554. . . Support column</p><p>558. . . Grinding head actuator</p><p>562. . . Grinding head shaft</p><p>602. . . Processing tank</p><p>606. . . Base</p><p>610. . . platform</p><p>620. . . Grinding head</p><p>624. . . Drive System</p><p>626. . . arm</p><p>700. . . Processing tank</p><p>704. . . plate</p><p>708. . . Buckle</p><p>720. . . Cover</p><p>724. . . Entrance</p><p>628. . . Transfer station</p><p>702. . . Abrasive pad assembly</p><p>706. . . vehicle</p><p>7l0. . . Grinding head</p><p>722. . . Vent</p>

The invention as briefly described in the Summary of the Invention will be described in more detail with reference to the specific embodiments of the invention illustrated in the drawings. It is to be understood, however, that the appended claims

Figure 1 is a cross-sectional view showing one embodiment of the treatment tank of the present invention;

Figure 2 is an exploded cross-sectional view of one embodiment of a polishing pad assembly;

3A-B are various embodiments of conductive pads;

4A-B is a partial cross-sectional view of another embodiment of a processing tank;

4C is a plan view of a specific embodiment of the polishing pad assembly shown in the processing tank of FIG. 4A;

Figure 5 is a cross-sectional view of another embodiment of a processing tank;

Figure 6 is a plan view of one embodiment of a grinding system;

Figure 7 is a cross-sectional view of another embodiment of a processing tank. To help understand, use the same reference number to represent the same component that is common to several schemas.

[Technical field to which the invention pertains]

Specific embodiments of the invention relate to methods and apparatus for planarizing a surface of a substrate.

[Prior Art]

In the manufacture of integrated circuits and other electronic devices, a plurality of layers of conductive materials, semiconductor materials, and dielectric materials are deposited on or removed from the surface of the substrate. Thin layer conductive materials, semiconductor materials, and dielectric materials can be deposited by some deposition techniques. Common deposition techniques in modern processing include physical vapor deposition (PVD), chemical vapor deposition (CVD), and electrochemical plating (ECP).

When the material layer is continuously deposited and removed, the uppermost surface of the substrate may become uneven and the entire surface needs to be flattened. A planarized surface or "grinding" surface is a method of removing material from the surface of a substrate to form a substantially uniform, flat surface. Flattening helps remove unwanted surface topography and surface defects such as agglomerated materials, lattice damage, scratches, and contaminated layers or materials. Planarization also helps to form features on the substrate by removing excess deposited material used to fill the features and provide a uniform surface for subsequent metallization and processing.

Chemical mechanical planarization or chemical mechanical polishing (CMP) is a common technique used to planarize substrates. CMP uses a chemical composition that selectively removes material from a substrate, typically a slurry or other fluid medium. In the conventional CMP technique, a substrate carrier or a polishing head is mounted on a carrier assembly in a CMP apparatus and placed in contact with the polishing head. The carrier assembly provides controlled pressure to the substrate to push the substrate against the polishing pad. The polishing pad is moved relative to the substrate by an external driving force. The CMP apparatus creates a grinding or rubbing motion between the surface of the substrate and the polishing pad while dispersing the abrasive composition to produce chemically and/or mechanically active and indirectly removing material from the surface of the substrate.

One material that is increasingly used in the fabrication of integrated circuits is copper, due to its desirable electrical properties. However, copper itself has special manufacturing problems. For example, it is difficult to pattern and etch copper, and it is difficult to form copper substrate features using new methods and techniques such as damascene or double damascene. Among the metal damascene methods, the features are defined by dielectric materials and subsequently filled copper. Dielectric materials having a low dielectric constant (in other words, less than about 3) are used in the fabrication of copper damascene. The barrier material is deposited conformally over the feature surface on the dielectric layer prior to deposition of the copper material. The copper material is then deposited over the barrier layer and the environmental field. However, the characteristic copper filling typically results in excess copper material or overload on the surface of the substrate, which must be removed or overloaded to form copper-filled features in the dielectric material and to prepare substrates for subsequent processing. surface.

One of the challenges in grinding copper materials is that the conductive material and the barrier material are typically removed from the surface of the substrate at different rates, both of which can cause excess conductive material to remain as a residue on the surface of the substrate. In addition, the surface of the substrate can have different surface topography depending on the density or size of the features formed in the substrate. The different surface topography along the surface of the substrate removes the copper material at different removal rates, making the effective removal of the copper material from the substrate surface and the final flatness of the substrate surface difficult to achieve.

One solution to grinding copper in low dielectric materials and reducing or minimizing defects above the copper is to grind copper by electrochemical mechanical polishing (ECMP) techniques. ECMP technology removes conductive material from the surface of the substrate by electrochemical dissolution while utilizing reduced mechanical wear compared to conventional CMP methods. Electrochemical dissolution is typically performed by applying an electrical bias between the cathode and the surface of the substrate, removing the conductive material from the surface of the substrate into the surrounding electrolyte. In an electrochemical dissolution process, the substrate is typically moved relative to the polishing pad to promote removal of the material from the surface of the substrate. In one embodiment of the ECMP system, an electrical bias is applied by a conductive contact that protrudes from the polishing pad. During the grinding process, the electrically conductive contact is brought into contact with the surface of the substrate to apply an electrical bias to the substrate.

Some ECMP systems use a conductive ring to bias the substrate during processing. However, the conductive ring may not be able to continuously and/or uniformly contact the substrate surrounding the circumference of the ring, resulting in an uneven electric field across the entire diameter of the substrate, which results in poor processing uniformity. Moreover, near the conductive ring, the electric field strength is generally strong, which can disadvantageously result in faster processing near the edge of the substrate.

An ECMP system that substantially reduces the non-uniformities associated with conductive contact rings used in ECMP processing uses a polishing pad having embedded conductive elements therein. The conductive element (eg, a plurality of brushes) protrudes from the polishing pad to contact the substrate to be treated on the polishing pad.

After several grinding cycles, the conductive elements need to be replaced to ensure good grinding performance. In addition, it is difficult to handle the polishing pad without damaging the conductive elements. Therefore, it is often impossible to know the overall life of the polishing pad. Thus, the need to replace conductive elements and polishing pads can adversely affect the cost of consumables.

Therefore, there is a need for improved grinding equipment.

[Summary of the Invention]

Aspects of the present invention generally provide methods and apparatus for abrading layers on a substrate using electrochemical deposition techniques, electrochemical dissolution techniques, abrasive techniques, and/or combinations thereof. In one aspect, an apparatus for polishing a substrate includes a polishing pad assembly having a conductive pad, a pad, and a conductive layer for biasing by a power source. The polishing pad assembly is configured as a single body that is easily replaceable in an electrochemical processing system.

In another embodiment, an apparatus for abrading a substrate includes a disk having a first electrode and a second electrode, the first electrode and the second electrode being coupled to the bottom of the disk. A dielectric pad is disposed in the disk and has a first opening and a second opening formed through the dielectric pad. The first electrode portion extends through the first opening while the second electrode portion extends through the second opening.

In another aspect of the invention, a method for electrochemically treating a substrate is provided. In one embodiment, a method for electrochemically treating a substrate includes the steps of: positioning a substrate in contact with a surface of a dielectric pad, the dielectric pad having a first opening formed in the surface and a second opening, the substrate and the dielectric pad are moved relative to each other, a first conductive path is formed between the anode and the substrate through the first opening, and a cathode and the substrate are formed through the second opening A second conductive path is created between.

[Embodiment]

Unless otherwise defined herein, the words and phrases used herein are intended to be in the ordinary and Chemical mechanical milling should be broadly interpreted and includes, but is not limited to, abrasion of the substrate surface by chemical activity, mechanical activity, or a combination of chemical and mechanical activity. Electropolishing should be broadly interpreted and includes, but is not limited to, the application of electrochemical activity to planarize the substrate. Electrochemical mechanical polishing (ECMP) should be broadly interpreted and includes, but is not limited to, the use of electrochemical activity or a combination of electrochemical and mechanical activity to remove material from the surface of the substrate while planarizing the substrate. Electrochemical mechanical plating (ECMPP) should be widely interpreted and includes, but is not limited to, the use of electrochemical activity or a combination of electrochemical and mechanical activity to electrochemically deposit material on a substrate while planarizing it. Deposited material.

Anodic dissolution should be broadly interpreted and includes, but is not limited to, the direct or indirect application of an anodic bias to a substrate that causes the conductive material to be removed from the surface of the substrate into the surrounding electrolyte solution. Openings are to be interpreted broadly and include, but are not limited to, perforations, holes, openings, grooves, channels or passages formed partially or completely through the object. Moreover, the use of the term "substantially" to modify "flat" is intended to describe a surface having no surface roughness at a macroscopic or global level.

1 is a cross-sectional view of one embodiment of a processing bath 100 in which at least one of the procedures including anodic dissolution, plating, and grinding procedures can be performed. Processing tank 100 typically includes a disk 104 and a polishing head 102. The substrate 108 is held in the polishing head 102 and then lowered to the disk 104 in a face down (e.g., back up) during processing. The electrolyte is allowed to flow into the disk 104 and contact the surface of the substrate while the polishing head 102 positions the substrate 108 in contact with the polishing pad assembly 122. The substrate 108 and the polishing pad assembly 122 disposed in the disk 104 are moved relative to each other to provide a polishing action (or an action that enhances plating uniformity). The grinding action is typically among a number of other actions, including at least one of the actions defined by orbital motion, rotational motion, linear motion, or curvilinear motion, or a combination thereof. The lapping action can be accomplished by moving one or both of the abrading head 102 and the disk 104 simultaneously. The polishing head 102 can be stationary or driven to provide relative movement of at least a portion between the disk 104 and the substrate 108 sandwiched by the polishing head 102. In the particular embodiment illustrated in FIG. 1, the abrading head 102 is coupled to the drive system 110. The drive system 110 moves the polishing head 102 in at least one of a rotational motion, an orbital motion, a sweep motion, or a combination thereof.

The polishing head 102 typically holds the substrate 108 during processing. In one embodiment, the abrading head 102 includes a housing 114 that encloses the bladder 116. When the bladder 116 is in contact with the substrate, the gas in the bladder can be withdrawn to create a vacuum between the two, thereby securing the substrate to the polishing head 102. In addition, the bladder 116 can be inflated to compress the substrate into contact with the polishing pad assembly 122 held on the disk 104. The buckle 138 is coupled to the outer cover 114 and confines the substrate 108 to prevent the substrate from slipping out of the polishing head 102 during processing. A grinding head that can be used to obtain the benefits of the present invention is TITANHEAD^TMThe carrier head is commercially available from Applied Materials, Inc. (Santa Clara, California). Another example of a polishing head that can be used to obtain the benefits of the present invention is described in U.S. Patent No. 6,159,079, issued on Dec.

The disc 104 is typically made of a plastic such as fluoropolymer, Teflon®, perfluoroalkoxy (PFA), polyethylene (PE), polyphenylether oxime (PES) or with electroplating or electropolishing. Made of other materials that are chemically compatible. The disk 104 includes a bottom portion 144 and side walls 146 that define a container that can receive the polishing pad assembly 122.

Sidewall 146 includes a port 118 formed through the sidewall to allow electrolyte to drain from disk 104. A port 118 is coupled to the valve 120 to selectively drain or retain the electrolyte in the disk 104. The disk 104 is rotatably supported above the base 106 by bearings 134. Drive system 136 is coupled to disk 104 and rotates disk 104 during processing. The receiving tray 128 is disposed on the base 106 and confines the disk 104 to collect a working fluid, such as an electrolyte, that flows through the port 118 through the disk 104 during and/or after processing.

The electrolyte delivery system 132 is typically disposed adjacent to the disk 104. The electrolyte delivery system 132 includes a nozzle or outlet 130 that is coupled to an electrolyte supply source 142. The outlet 130 causes an electrolyte or other working fluid to flow from the electrolyte supply source 142 into the disk 104. During processing, the electrolyte typically provides an electrical path to bias the substrate 108 and drive an electrochemical process to remove and/or deposit material on the substrate 108.

An electrolyte that can be used to treat substrate 108 can cause metal (e.g., copper, aluminum, tungsten, gold, silver) or other materials to be electrochemically removed from substrate 108 and/or deposited onto the substrate. The electrolyte solution may contain a commercially available electrolyte. For example, in the removal of the copper-containing material, the electrolyte may contain a sulfuric acid-based electrolyte or a phosphate-based electrolyte and potassium phosphate (K)₃PO₄) or a combination thereof. The electrolytic solution may also contain a sulfuric acid-based electrolyte derivative (such as copper sulfate) and a phosphate-based electrolyte derivative (such as copper phosphate). An electrolyte having a perchloric acid-acetic acid solution and a derivative thereof can also be used. Furthermore, the present invention contemplates the use of electrolyte compositions conventionally used in electroplating or electropolishing procedures, including electroplating or electropolishing additives conventionally used, such as brighteners. In one aspect of the electrolyte solution, the electrolyte can be made from a composition having a concentration between about 0.2 and about 1.2 moles of the solution, such as copper sulfate.

For example, copper sulfate (CuSO) can be used.₄) as an electrolyte. One source of electrolyte solutions for electrochemical procedures (e.g., copper plating, copper anodic dissolution, or combinations thereof) is sold under the tradename ULTRAFILL 2000 by Shipley Leonel, a subsidiary of the Philadelphia-based Rohm and Hass division. Another example of an electrolyte is described in U.S. Patent Application Serial No. (No. 6712), the entire disclosure of which is incorporated herein by reference. Capabilities, high removal rates, and smooth surface treated electrolytes."

A processing device 150 can be provided proximate to the disk 104 to periodically process or regenerate the polishing pad assembly 122. Typically, the processing device 150 includes an arm 152 that is coupled to a post 154 that is adjusted to position such that the processing element 158 sweeps across the entire polishing pad assembly 122. The processing element l58 is coupled to the arm 152 by a shaft 156 to permit clearance between the arm l52 and the wall 146 of the disk 104 when the processing element 158 is lowered into contact with the polishing pad assembly 22. The processing element 158 is typically a diamond or tantalum carbide disk that can be patterned to cause the surface of the polishing pad assembly 12 to become a predetermined surface condition/state that enhances process uniformity. A processing element 158, which can be used to obtain the benefit of the present invention, is described in U.S. Patent Application Serial No. 09/676,280, filed on Sep. .

Power source 124 is coupled to polishing pad assembly 122 by electrical leads 11 (shown as ll2A-B). Power source 24 applies an electrical bias to polishing pad assembly 122 to drive the electrochemical procedure detailed below. The wire 11 passes through a slip ring l26 disposed under the disk 104. When the disc 104 rotates, the slip ring l26 can cause a continuous electrical connection between the power source l24 and the polishing pad assembly l22. The wire l12 is typically a wire, ribbon or other conductor that is compatible with the working fluid, or has a coating or coating that protects the wire 11 from damage by the working fluid. Examples of materials that can be used for wire l12 are among many other materials, including insulated copper, graphite, titanium, platinum, gold, and HASTELOY.^. The coating disposed around the wire 11 may include a polymer such as fluorocarbon, polyvinyl chloride (PVC), polyamide or the like.

2 is an exploded cross-sectional view showing one embodiment of a polishing pad assembly 122 that is movably disposed in the disk 104. While the illustrated polishing pad assembly 22 is used in electrochemical mechanical polishing (ECMP), the present invention contemplates the use of electrically conductive grinding media (mats) in other manufacturing processes associated with electrochemical activity. Examples of such procedures utilizing electrochemical activity include electrochemical deposition involving the use of conventional bias application devices (e.g., edge contact and electrochemical mechanical plating (ECMPP) including combined electrochemical deposition and chemical mechanical polishing). In the case of the polishing pad assembly 22, a uniform bias is applied to the substrate on which the conductive material is to be deposited. The polishing pad assembly 12 includes an element including both an anode and a cathode of the electrochemical cell, and both the anode and the cathode can be removed from the disk 104 by merely using the used polishing pad assembly 22, and then have a new power. The new polishing pad assembly 122 of the component is inserted into the disk 104 while being replaced.

The polishing pad assembly 12 described in FIG. 2 includes a conductive pad 202 that is coupled to the pad 204. Pad 204 is attached to electrode 206. Typically, the conductive pads 202, pads 204, and electrodes 206 are secured together to form a unitary body that allows the polishing pad assembly 22 to be easily removed and replaced from the disk 104. Typically, the conductive pads 202, pads 204, and electrodes 206 are adhered or bonded to each other. In the particular embodiment illustrated in Figure 2, the conductive pads 202, pads 204 and electrodes 206 are permanently bonded together using an adhesive. Or by means of other methods or combinations thereof, among other numerous methods including stitching, bonding, heat staking, riveting, locking and clamping, the conductive pad 202, the pad 204 and the electrode 206 are combined. .

The conductive pad 202 includes a dielectric pad body 260 and one or more conductive elements 262. The conductive element 262 is connected to the power source 14 via a wire 1222A and is in contact with the surface of the substrate which is disposed on the dielectric pad body 260 during processing. A number of methods can be utilized that facilitate a good electrical connection between the conductive element 262 and the power source l24, such as by soldering, overlapping, brazing, clamping, crimping, riveting, snapping, conductive bonding, or by other means. The method, or a device that facilitates a good electrical connection between the wire l12A and the conductive element 262, connects the wire 112A to the conductive element 262.

The dielectric pad body 260 is typically made of a polymeric material that is compatible with the procedural chemistry, examples of which include polyurethanes, polycarbonates, fluoropolymers, polytetrafluoroethylene (PTFE), polytetrafluoroolefins (PTFAs). Polyphenylene sulfide (PPS) or a combination thereof, and other abrasive materials used to polish the surface of the substrate. The dielectric pad body 260 may also contain a filler and/or a foam to be foamed. Exemplary materials for exemplification include those made from polyurethane and/or polyurethane mixed with a filler, which is commercially available from Freudenberg's FX9 pad. Other conventional abrasive materials (e.g., a layer of compressible material) may also be used as the dielectric pad body 260. Compressible materials include, but are not limited to, soft materials such as compressed felt fibers that are leached with polyurethane or foam. The thickness of the dielectric pad body 260 is typically between about 10 and about 100 mils.

The dielectric pad body 260 has a first side 208 and a second side 210. During processing, the first side 208 is brought into contact with the substrate 108 (shown in phantom in the second figure). The first side 208 can include grooves, embossments, or other texture to enhance abrasive performance. The dielectric pad body 260 can be solid impermeable electrolyte, permeable electrolyte or porous. The first side 208 further includes one or more slots 264 or other features that can hold the conductive element 262. In the particular embodiment illustrated in FIG. 2, the dielectric pad body 260 is porous, having a plurality of apertures 212 through which the electrolyte can flow and a plurality of slots 264 having conductive elements 262 disposed therein.

Conductive element 262 can comprise a conductive polymer, a polymeric composite comprising a conductive material, a conductive metal or polymer, a conductive filler, a graphite material, or a conductive dopant material, or a combination thereof. Conductive element 262 typically has an overall electrical resistance or overall surface resistance of about 10 ohm-cm or less. In the particular embodiment illustrated in FIG. 2, conductive element 262 is a plurality of electrically conductive fibers, seats and/or flexible jaws, such as carbon fibers or other electrically conductive compliant (ie, flexible) that are in contact with the substrate during processing. )material. Alternatively, the conductive element 262 can be a roller, a ball, a rod, a rod, a screen, or other shape that facilitates conductive contact between the substrate disposed on the conductive pad 202 and the power source 124. An example of a conductive pad that can be used to obtain the benefits of the present invention is described in U.S. Provisional Patent Application Serial No. 60/342, No. 28, filed on Jan. 19, 2011. No. (Patent Agent File Number No. 6636 / CMP/CMP/RKK), entitled "Method and Apparatus for Surface-Oriented Surface Grinding"; and U.S. Patent Application Serial No. 10, filed on Dec. 27, 2001 /033, 732, the entire contents of each of which is incorporated herein by reference.

The pad 204 is connected to the second electrode 210 of the dielectric pad body 260. Pad 204 is typically made of a material that is softer or more compliant than the material of dielectric pad body 260. The difference in hardness or hardness gauge between the dielectric pad body 260 and the liner 204 can be selected to produce the desired abrasive/plating performance. Pad 204 can also be compressible. Examples of suitable gasket materials include, but are not limited to, foamed polymers, elastomers, felts, impregnated felts, and plastics that are compatible with the abrasive chemistry.

The gasket 204 has a first side 214 and a second side 216. The first side 214 is coupled to the second side 210 of the dielectric pad body 260. Pad 204 typically has a thickness in the range of from about 5 to about 100 mils, and in one embodiment, is about 5 mils thick. The liner 204 can be a solid impermeable electrolyte, a permeable electrolyte, or a porous one. In one embodiment illustrated in FIG. 2, liner 204 is configured to pass electrolyte through the liner, and the liner can be permeable, having a hole formed through the liner or a combination thereof. In the particular embodiment illustrated in Figure 2, the liner 204 is a porous body having a plurality of openings 218 through which electrolyte can flow. The opening 218 of the gasket 204 is generally (but not necessarily) aligned with the opening 212 of the dielectric pad body 260.

Electrode 206 typically includes materials to be deposited or to be removed, such as copper, aluminum, gold, silver, tungsten, and other materials that can be electrochemically deposited on substrate 108. For electrochemical removal procedures (eg, anodic dissolution), electrode 206 can include a non-consumable electrode of a material other than the deposited material, such as platinum for copper dissolution. This non-consumable electrode is used in conjunction with the planarization procedure for both electrochemical deposition and removal.

Alternatively, electrode 206 can be a consumable. When the polishing pad assembly 122 may be easily replaced as a unit, can be quickly and efficiently replace the polishing pad of the total to 122 and 206 to be regularly electrode does not substantially affect the amount of processing. Moreover, the electrode 206 can be configured to have a similar lifetime to the conductive pad 202 so that replacement of the polishing pad assembly 122 can complement both the electrode 206 and the conductive pad 202. Moreover, the electrode 206 is recessed from the first side 208 of the dielectric pad body 260 (in other words, in a spatially separated relationship), the first side 208 of the dielectric pad body 260 can be easily handled without damaging the electrode. 202 or a situation that causes damage or scratching of the substrate. The polishing pad assembly 122 is treated as appropriate during substrate processing.

The electrode 206 has a first side 220 and a second side 222. The first side 220 of the electrode 206 is coupled to the second side 216 of the gasket 204. Electrode 206 can be a solid impermeable electrolyte, a permeable electrolyte or a porous one. In the particular embodiment illustrated in Figure 2, electrode 206 is configured to pass an electrolyte through the electrode. Electrode 206 can be permeable, having a hole formed through the electrode or a combination thereof. The thickness of the electrode 206 can range from foil to greater than 100 mils.

The second side 222 of the electrode 206 is disposed on the bottom portion l44 of the disk 104. The second side 222 is connected to a wire 1212, which is typically passed through a disk 104 to a power source 124 (as shown in FIG. 1) along with a wire 11A (connected to a dielectric pad body 260). A number of methods can be utilized that facilitate a good electrical connection between the electrode 206 and the power source l24, such as by soldering, overlapping, brazing, clamping, crimping, riveting, snapping, conductive bonding, or by Other methods or devices that facilitate a good electrical connection between the wires l12A-B and the electrodes 206 connect the wires 11B to the second side 222. Alternatively, the wires ll2A-B can pass over the side wall 146 of the disk 104 to the power source l24 to eliminate the liquid seal surrounding the wires l12A-B and the disk 104. Depending on the situation

The wires 112A-B are connected to the power source l24 using a single open circuit 266 that is typically configured in the disk 104 to further facilitate the removal of the polishing pad assembly 122. The second side 222 of the electrode 206 can be bonded to the bottom portion 144 of the disk 104 by a removable adhesive to prevent movement of the polishing pad assembly 122 during the grinding process while permitting the polishing pad assembly 22 to be replaced. The polishing pad assembly l22 can be clamped, snapped or fastened to the disk 104 by other methods.

When the polishing pad assembly 12 is disposed directly on the bottom portion 44 of the disk 104, there is typically no intervening member, and the side walls 146 of the disk 104 can be much shorter than conventional designs to form shallow processing grooves. This shallow design of the disk 104 facilitates minimizing the amount of electrolyte used during processing. Since only a small amount of electrolyte is required at this time, it is most cost-effective to dispense the electrolyte after a single use, and it is also possible to dispense with the current state of the art system for the expensive electrolyte circulation and monitoring systems currently in use. Demand.

3A-B depict a specific embodiment of two alternative polishing pad assemblies. Referring to FIG. 3A, the polishing pad assembly 300 includes a conductive pad 302 that is coupled to the pad 304 and the electrode 306 to form a single, replaceable body that enables the polishing pad assembly 300 to be easily removed from the disk 104. In addition to replacement. Typically, the conductive pad 302, pad 304, and electrode 306 are bonded or bonded to each other as the polishing pad assembly 122 described above. The conductive pad 302 includes a dielectric pad 332 and one or more conductive members 332 that are similar to the conductive pads 202. Electrode 306 is configured to resemble electrode 206 of polishing pad assembly 122. Pad 304 is generally similar to pad 204 except that pad 304 does not include an aperture.

Referring to FIG. 3B, the polishing pad assembly 310 includes a conductive pad 302 that is coupled to the pad 312 and the electrode 314 to form a single, replaceable body that enables the polishing pad assembly 310 to be easily removed from the disk 104. In addition to replacement. Typically, the conductive pads 302, pads 312, and electrodes 314 are bonded or bonded to each other as the polishing pad assembly 122 described above. Conductive pad 302 and pad 314 are configured to resemble conductive pad 202 and pad 314 of polishing pad assembly 122. Electrode 312 is generally similar to electrode 206 except that electrode 312 includes an aperture 316 formed through the electrode that allows electrolyte to pass through electrode 312. In one embodiment, the openings 212, 316, and 318 are aligned to cause electrolyte to flow through the polishing pad assembly 310 with minimal resistance.

The main operation mode of the processing tank 100 is explained mainly with reference to FIG. During operation, the substrate 108 is held in the polishing head 102 and moved over the polishing pad assembly 122 disposed in the disk 104. The polishing head 102 is lowered toward the disk 104 to position the polishing pad assembly 122 at a location in contact with the substrate 108 or at least proximate to the substrate. The electrolyte is supplied to the polishing head 102 through the outlet 130 and into the polishing pad assembly 122 through the openings 212, 218 in the upper layers of the polishing pad assembly 122 (ie, the conductive pads 202 and pads 204).

The power source 124 applies a bias voltage between the conductive elements 262 of the conductive pads 202 and the electrodes 206 of the polishing pad assembly 122 by rotating the tube segments l40. Conductive element 262 is in contact with the substrate and biases the substrate. The electrolyte filled in the openings 21, 218 between the electrode 206 and the substrate 108 provides a conductive path between the power source l24 and the substrate 108 to drive the electrochemical polishing process by anodic dissolution. This results in the removal of a conductive material (e.g., copper) deposited on the surface of the substrate 108.

The substrate 108 and the polishing pad assembly 12 are moved relative to each other to uniformly grind the surface of the substrate. Typically, a contact force of about 6 psi or less is used to hold the substrate 108 against the polishing pad assembly 122. When grinding a substrate containing a low dielectric constant material, a contact force of about 2 psi or less can be used.

During the anodic dissolution process, the electrode 206 of the polishing pad assembly 12 is biased as a cathode, and the conductive pad 202 and substrate 108 are biased as an anode. Applying a bias will cause the deposited material to be removed from the surface of the substrate. This biasing can include applying a voltage of about 15 Volts or less to the surface of the substrate. The copper-containing material can be dissolved from the surface of the substrate into the electrolyte using a voltage between about 0.1 Volts and about 10 volts. Alternatively, the bias voltage can be between about 0.1 milliamps/cm²And about 50 mil1iamps/cm²The current density between, or for a 200 mm substrate, is between about 0.lamps to about 20 amps. A conventional polishing apparatus that applies a bias voltage to a substrate by a conductive pad 202 than a substrate is biased by a periphery of the substrate to provide a more uniform dissolution of the conductive material (eg, metal) from the surface of the substrate to the electrolyte. Among them.

The bias applied to perform the anodic dissolution procedure can vary depending on the power and the manner of application, depending on the user's requirements in removing the material from the surface of the substrate. For example, the conductive pad 202 can be provided with a time varying anode potential. The bias voltage can also be applied by electrical pulse modulation techniques. In a specific embodiment, the electrical pulse modulation technique includes applying a constant current density or a constant voltage over the substrate during the first time period, and then applying a rectification voltage over the substrate during the second time period, and repeating the first And the second step. For example, electrical pulse modulation techniques can use a variable potential between about -0.1 volts and about -15 volts to between about 0.1 volts and about 15 volts.

The electrically conductive material may be removed from at least a portion of the surface of the substrate at a rate of between about 15,000 Å/min or less, such as between about 100 Å/min and about 1,500 Å/min. In one embodiment of the invention, the thickness of the copper material to be removed is less than 12,000 Å, and a voltage can be applied to the polishing pad assembly 12 to provide between about 100 /min and about 8,000 Å/min. The rate of removal.

4A-B depicts another embodiment of a processing tank 400. The processing tank 400 is generally similar to the processing tank 100 described above except that at least the first electrode 402 and the second electrode 404 are coupled to the disk 406 and separated from the polishing pad assembly 408 disposed in the disk 406.

The disk 406 generally includes a sidewall 410 and a bottom 412. Each electrode 402, 404 is connected to the bottom portion 42 of the disk 406 in a spatially separated relationship. Each of the electrodes 402, 404 is connected to a different pole of the power supply 418 via individual wires 414, 416 through a slip ring 440 disposed below the disk 406.

In the specific embodiment illustrated in Figure 4A, the first electrode 402 is configured as a non-consumable anode, typically made of a noble metal such as platinum, gold, graphite, or the like. The second electrode 404 is configured as a cathode, which is typically made of a highly conductive material, examples of which are precious metals, aluminum, and copper among many other materials.

The polishing pad assembly 408 generally includes a dielectric body 430 having an abrasive surface 420 and an opposite second surface 422 for contacting the substrate during processing. At least a first opening 424 and a second opening 426 are formed between the abrasive surface and the second surface 420, 422 by the polishing pad assembly 408. When the polishing pad assembly 408 is disposed at the bottom 412 of the disk 406, the first and second apertures 424, 426 are individually configured to receive the first and second electrodes 402, 404. The thickness of the body 430 is selected to maintain the electrodes 402, 404 under the polishing pad 420 during the polishing process, thereby substantially preventing the electrodes 402, 404 from contacting the substrate 108 being processed on the polishing pad assembly 408. In one embodiment, the electrodes 402, 404 protruding above the bottom 412 of the disk 406 have a recess of less than about 50 mils. In one embodiment, the electrode has an abrasive surface 420 from the body 430 of about 10 To a recess of approximately 30 mils. The polishing pad assembly 408 can optionally include a pad 432 (shown in phantom in Figure 4A) coupled to the second surface 422 to provide greater control over the abrasive properties of the polishing pad assembly 408.

The openings 424, 426 (and electrodes 402, 404) are typically spaced or configured to periodically expose at least a portion of each opening 424, 426 to the atmosphere during processing. In other words, when the substrate 108 substantially covers the openings 424, 426 during processing, the periodically exposed portions of the openings 424, 426 release the gas present between the electrodes 402, 404 and the substrate 108, thus Improve grinding uniformity. Alternatively, the present invention contemplates the use of a high electrolyte flow rate to purge the gases present between the electrodes 402, 404 and the substrate 108. When the substrate 108 has not directly covered the electrodes, no power is supplied to the electrodes 402, 404.

As depicted in the top view of one embodiment of the body 430 of Figure 4C, the apertures 424, 426 are configured to have a greater distance than the opposite outer edges 452, 454 of the diameter of the substrate to be grounded, while The distance between the inner edges 456, 458 of the openings 424, 426 that are smaller than the diameter of the substrate to the outer edges 452, 454 of the opposing openings.

Moreover, when the electrodes 402, 404 have recesses below the abrasive surface 420 of the body 430, the polishing pad assembly 408 can be processed without damaging the electrodes 402, 404. Therefore, in the case where the electrical properties of the trench 400 are not deteriorated, it is advantageous to increase the life of the polishing pad assembly 408. Since only the main body 430 is replaced during operation (and when there is a pad 432 in use), it is advantageous to minimize both consumable cost and replacement speed.

During operation, when power supply 418 applies a bias to each of electrodes 402, 404, the area in each opening 424, 426 between electrodes 402, 404 and substrate 108 is filled with electrolyte and becomes two Separate electrochemical cells 460, 462. In the trench 402 above the second electrode 404, OH ions will migrate toward the second electrode 404 and generate O₂bubble. H^＋Ions migrate to the metal surface (on the substrate) and generate H₂. Reach H₂The electrons required to generate are provided by a simultaneous process in the battery 460 above the first electrode 402. In the battery 460, Cu or other metal film present on the surface of the substrate 108 loses electrons into the electrolyte, and metal ions (such as H)⁺) will migrate to the first electrode 402. This dual battery program completes the current loop without grinding the metal film on substrate 10 by contact with the solid conductor.

Figure 5 depicts a specific embodiment of a polishing system 500 having an over-electrochemical electrochemical deposition and/or chemical mechanical polishing (e.g., mechanical polishing (ECMP) or electrochemical mechanical plating (ECMPP) station) Processing tank 502. The processing tank 502 generally includes a disk 542 and a polishing head assembly 510 having a disk assembly 506 disposed above the disk and the polishing head assembly 510 supported above the disk assembly 506 by a polishing head assembly bracket 552. The disk assembly 506 is generally similar to the disk 104 described above and can be coupled to the disk 542 or to one or more bearings 508 (one of which is shown) rotated above the disk 542. Alternatively, the disk assembly 506 can be configured similar to the disk 406 using the polishing pad assembly 408.

The polishing head assembly 510 includes a polishing head 512 that can hold the substrate 108 and be movable to position the substrate 108 in contact with the polishing pad assembly 122, the polishing pad assembly being attached to the process It remains in the disk assembly 506. The polishing head 515 is generally similar to the polishing head 102 described above.

The abrading head assembly 510 is typically mounted to a grinding head assembly bracket 552 that includes a support post 554 and a cantilevered spoke 556. The support post 554 is mounted to the base 542 of the grinding system 500, and the cantilevered spokes 556 are laterally projecting from the upper portion of the support post 554. The support post 554 can provide rotation relative to the vertical axis along the support post to permit lateral movement of the polishing head assembly 510. The abrading head assembly 510 is attached to a device plate 560 disposed at the end of the cantilevered radiation 556. The lower end of the cantilevered spoke 556 is coupled to a cantilevered radiating actuator 520, such as a pneumatic cylinder, mounted on a support post 554. The cantilevered actuator 520 provides a pivotal movement relative to the cantilevered spoke 556 that engages between the cantilevered spoke 556 and the support post 554. When the cantilevered actuator 520 is retracted, the cantilevered spokes 556 will remove the abrasive head assembly 510 from the disk assembly 506 to provide the space needed to remove or load the substrate from the disk assembly 506 of the grinding system 500. . When the cantilevered actuator 520 is extended, the cantilevered projection 556 moves the polishing head assembly 510 and the substrate 108 toward the disk assembly 506 to contact the polishing pad assembly 122 held in the disk assembly 506. .

The abrading head assembly 510 generally includes a grinding head 512 and a grinding head actuator 558. Grinding head actuator 558 is coupled to device plate 560 and includes a grinding head shaft 562 that extends downwardly through device plate 560. The lower end of the grinding head shaft 562 is coupled to the grinding head 512 to allow the grinding head 512 to move vertically.

In addition, the abrading head actuator 558 can be configured to provide rotation of the abrading head 512. During the anodic dissolution procedure, the relative motion between the substrate and the abrading head 512 generally improves the grinding effect. The polishing head 512 can also be rotated when the polishing head 51 is lowered to bring the substrate into contact with the polishing pad assembly 122 disposed in the disk assembly 506 and when the polishing head 512 is in the raised or partially raised position. At elevated or partially elevated positions, the abrading head 512 can be rotated to remove electrolyte from the abrading head 512.

Figure 6 depicts a specific embodiment of a grinding system 600 having an electrochemical mechanical polishing (ECMP) station or a chemical mechanical polishing station for electrochemical deposition and/or chemical mechanical polishing (e.g., disposed on a base 606). At least one processing tank 602 of 604). Substrate transfer mechanism 608 is coupled to base 606 for transporting the substrate between processing tank 602 and grinding station 604. Treatment tank 602 is generally similar to treatment tank 100 described above.

The transfer mechanism 608 typically includes at least one polishing head 620 that is similar to the polishing head 102 described above. In the particular embodiment illustrated in Figure 6, the transport mechanism 608 includes a transport device, such as a rotary magazine 622, which rotatably supports a plurality of polishing heads 620 (three are shown). Each of the polishing heads 620 is coupled to the rotary rack by an arm 626. One arm 626 and grinding head 620 are removed to display transfer station 628. One type of transfer station that can be used to obtain the benefits of the present invention is described in U.S. Patent No. 6,156,124, issued to A.S.

Each of the polishing heads 620 can be selectively positioned over one of the processing tank 602 and the polishing station 604 to process the substrate. The substrate can be continuously processed by any of the processing tank 602 and/or the polishing station 604 while maintaining the substrate in a single polishing head 620. A drive system 624 is coupled to each of the polishing heads 620 to facilitate a grinding action between at least a portion of the polishing station 604 between the substrate and the processing tank 602 or below the drive system. &lt;/ RTI&gt; &lt;RTIgt; &lt;/ RTI&gt; &lt;RTIgt; &lt;/ RTI&gt; &lt;RTIgt; &lt;/ RTI&gt; &lt;RTIgt; &lt;/ RTI&gt; &lt;RTIgt; &lt;/ RTI&gt; &lt;RTIgt; &lt;/ RTI&gt; &lt;RTIgt;

The polishing station 604 typically includes a rotatable platform 610 that supports abrasive material 615. The abrasive material 612 is typically made of a polymeric material that is compatible with the procedural chemistry, examples of which include polyurethanes, polycarbonates, fluoropolymers, polytetrafluoroethylene (PTFE), polytetrafluoroolefins (PTFAs), poly Phenyl sulfide (PPS) or a combination thereof, and other abrasive materials used to polish the surface of the substrate. The abrasive material 612 may also contain a filler and/or a foam to be foamed. Exemplary prior art materials include those made from polyurethanes and/or polyurethanes mixed with fillers, which are commercially available from Freudenberg. FX9 pad. Other conventional abrasive materials (e.g., a layer of compressible material) may also be used as the abrasive material 612. Compressible materials include, but are not limited to, soft materials such as compressed felt fibers that are leached with polyurethane or foam. Alternatively, the abrasive material 612 may be in the form of abraded mesh layers containing a plurality of abrasive elements suspended in a polymeric binder that is stretched between the rollers disposed on each side of the platform 610. Typically, a grinding medium (e.g., a slurry, deionized water, or other liquid or abrasive compound) is provided between the abrasive material 612 and the substrate supported in the polishing head 620 to promote removal of the material from the substrate. A pulverizing system that can be used to obtain the benefits of the present invention is described in U.S. Patent No. 6,244,935, issued to Jun.

Figure 7 is another embodiment of a processing tank 700 that uses a polishing pad assembly 702 similar to the polishing pad assembly 310 described above. Processing tank 700 typically includes a tray 704 that holds substrate 108 within the tray during processing. The disk 704 typically includes a carrier 706 and a buckle 708. Carrier 706 is used to support the substrate within the tray 704. Buckle 708 is attached to carrier 706 and confines substrate 108 to substantially limit movement of the substrate during processing.

The polishing head 710 is movably disposed above the disk 704. The polishing pad assembly 702 is securely attached to the outer cover 720 of the polishing head 710. The polishing pad assembly 702 and the conductive pads 302 of the polishing pad assembly 702 are brought together toward the disk 704 and the electrodes 314. The electrolyte enters the polishing head 710 through an inlet 724 formed in the outer cover 720. The electrolyte flows from the inlet 724 through the polishing pad assembly 702 to the substrate 108 disposed in the disk 704. Alternatively, the disk 704 can be filled with electrolyte to a level that can wet the electrode 314 of the polishing pad assembly 702 inside the polishing head 710.

The outer head 720 of the polishing head 710 generally includes a vent 722 formed in the polishing head. Gas generated at electrode 314 (or otherwise on the surface of the substrate) will pass through the opening in polishing pad assembly 702 and exit housing 720 via vent 722. The exhaust gas can improve program uniformity by preventing electrical insulation of the surface of the substrate by replacing the electrolyte with bubbles. A treatment tank that can be used to obtain the benefits of the present invention is described in U.S. Provisional Patent Application Serial No. 60/342,281, filed on Dec. 19, 2001, which is hereby incorporated by reference.

Accordingly, the present invention substantially reduces the amount of consumables used in the process by minimizing the amount of electrolyte used and promoting polishing pad processing. In addition, when the polishing pad is always a single body, the replacement of the polishing pad assembly can be minimized. For its part, the electrochemical treatment efficiency of the substrate can be improved.

While the above is directed to the various embodiments of the present invention, other or further embodiments of the present invention may be devised without departing from the basic scope of the invention. Determined.

Simple illustration

The invention as briefly described in the Summary of the Invention will be described in more detail with reference to the specific embodiments of the invention illustrated in the drawings. It is to be understood, however, that the appended claims

Figure 1 is a cross-sectional view showing one embodiment of the treatment tank of the present invention;

Figure 2 is an exploded cross-sectional view of one embodiment of a polishing pad assembly;

3A-B are various embodiments of conductive pads;

4A-B is a partial cross-sectional view of another embodiment of a processing tank;

4C is a plan view of a specific embodiment of the polishing pad assembly shown in the processing tank of FIG. 4A;

Figure 5 is a cross-sectional view of another embodiment of a processing tank;

Figure 6 is a plan view of one embodiment of a grinding system;

Figure 7 is a cross-sectional view of another embodiment of a processing tank. To help understand, use the same reference number to represent the same component that is common to several schemas.

Main component symbol description

L00. . . Processing tank

L04. . . plate

108. . . Substrate

L14. . . Cover

1l8. . . Port

L22. . . Abrasive pad assembly

L24. . . power supply

L28. . . Undertaking

132. . . Conveyor system

L36. . . Drive System

142. . . Electrolyte supply

L46. . . Side wall

152. . . Arm

156. . . axis

202. . . Conductive pad

206. . . electrode

2l0. . . Second side

214. . . First side

218. . . Opening

222. . . Second side

262. Conductive component

300. . . Abrasive pad assembly

L02. . . Grinding head

L06. . . Base

L10. . . Drive System

1l6. . . bag

120. . . valve

122A, 122B. . . wire

L26. . . Slip ring

130. . . Export

L34. . . Bearing

138. . . Buckle

144. . . bottom

150. . . Processing device

L54. . . pillar

L58. . . Processing component

204. . . pad

208. . . First side

212. . . Opening

2l6. . . Second side

220. . . First side

260. . . Dielectric pad body

264. . . groove

302. . . Conductive pad

304. . . pad

3l0. . . Abrasive pad assembly

3l4. . . electrode

400. . . Processing tank

404. . . Second electrode

408. . . Abrasive pad assembly

412. . . bottom

418. . . power supply

422. . . Second surface

426. . . Second opening

432. . . pad

452, 454. . . Outer edge

460, 462. . . Electrochemical battery

502. . . Processing tank

508. . . Bearing

5l2. . . Grinding head

552. . . support

556. . . Cantilever

560. . . Device board

600. . . Grinding system

604. . . Grinding station

608. . . Substrate transfer mechanism

6l2. . . Abrasive material

622. . . Rotary rack

306. . . electrode

3l2. . . pad

316, 3l8. . . Opening

402. . . First electrode

406. . . plate

410. . . Side wall

4l4, 416. . . wire

420. . . Abrasive surface

424. . . First opening

430. . . Dielectric body

440. . . Slip ring

456, 458. . . Inner edge

500. . . Grinding system

506. . . Disk assembly

5l0. . . Grinding head assembly

520. . . Cantilever actuator

554. . . Support column

558. . . Grinding head actuator

562. . . Grinding head shaft

602. . . Processing tank

606. . . Base

610. . . platform

620. . . Grinding head

624. . . Drive System

626. . . arm

700. . . Processing tank

704. . . plate

708. . . Buckle

720. . . Cover

724. . . Entrance

628. . . Transfer station

702. . . Abrasive pad assembly

706. . . vehicle

7l0. . . Grinding head

722. . . Vent