Manufacturing method of semiconductor device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a method for manufacturing a protruding electrode of a semiconductor device to a semiconductor device, and more particularly to a method for manufacturing a protruding electrode of a semiconductor device used for bare chip mounting in which the semiconductor device is directly connected to a substrate.

【0002】

[Conventional technology]

Bare chip mounting, in which a semiconductor device is directly connected to a substrate, is an ideal mounting method for electronic devices that are becoming smaller year by year. Among them, flip-chip mounting in which the element forming surface of a semiconductor device is connected toward the substrate side is a mounting method that has attracted particular attention.

【0003】

Among the protruding electrodes of the semiconductor device used for flip chip mounting, a straight wall-shaped protruding electrode suitable for miniaturization will be described with reference to the drawings. 8 to 10 are cross-sectional views showing a method of manufacturing a semiconductor device.

【0004】

First, the projection electrode structure of the prior art will be described with reference to FIG. As shown in FIG. 10, the semiconductor device 10 arranges a connection electrode pad 12 for connecting to the outside on the semiconductor element forming surface of the silicon substrate 11. A protective film 13 for the purpose of protecting the semiconductor element is provided so that the connection electrode pad 12 is exposed at the opening. The common electrode film 14 is provided on the connection electrode pad 12. Further, a protruding electrode 17 is formed on the common electrode film 14.

【0005】

Next, a method of manufacturing a protruding electrode in the prior art will be described. As shown in FIG. 8, the semiconductor device 10 is formed with a thickness of 1 μm on the element forming surface of the silicon substrate 11 in order to connect the connection electrode pad 12 made of aluminum to the outside. Further, a protective film 13 for the purpose of protecting the semiconductor element is formed on the entire surface of the silicon substrate 11 including the connection electrode pad 12. The protective film 13 is generally formed by using an inorganic film such as a phosphorus-containing silicon oxide film or a silicon nitride film, an organic film such as a polyimide resin, or a laminated structure thereof, and the film thickness is 3 μm. After that, the protective film 13 is opened so that the connection electrode pad 12 is exposed by photosoligraphy and etching in which an exposure development process is performed using a predetermined mask.

【0006】

The common electrode film 14 is formed on the entire surface of the silicon substrate 11 by a method such as a sputtering method or a vacuum vapor deposition method. The common electrode film 14 sequentially forms aluminum with a thickness of 0.8 μm, chromium with a thickness of 0.01 μm, and copper with a thickness of 0.8 μm.

【0007】

As shown in FIG. 9, a plated resist 16 made of a photosensitive resist is formed with a thickness of 20 μm on the entire surface of the common electrode film 14 formed on the silicon substrate 11. After that, an opening is provided on the common electrode film 14 on the connection electrode pad 12 by photolithography in which an exposure development process is performed using a predetermined mask. Further, a protruding electrode 17 made of gold is formed with a height of 15 μm by an electrolytic plating method.

【0008】

As shown in FIG. 10, the unnecessary plating resist 16 is removed, and the common electrode film 14 is removed by using the protruding electrode 17 as an etching mask.

【0009】

[Problems to be Solved by the Invention]

In order to improve the efficiency of mass productivity with the progress of semiconductor device manufacturing technology, the diameter of the semiconductor device 11 (wafer) has been increasing, and the 8-inch semiconductor device 11 has become the mainstream. When a common electrode film 14 having an aluminum thickness of 0.8 μm, a chromium thickness of 0.01 μm, and a copper thickness of 0.8 μm is formed on an 8-inch semiconductor device 11, the film stress of the common electrode film 14 causes the 8-inch semiconductor device 11 to have a thickness of 100 μm or more. Concave warp occurs. The warp of the concave semiconductor device 11 having a thickness of 100 μm or more has some adverse effects on the manufacturing process from the formation of the common electrode film 14 to the removal of the common electrode film 14.

【0010】

The first adverse effect is that vacuum adsorption failure occurs in the plating resist forming process. The plating resist is generally applied by rotation. As shown in FIG. 5, the plating resist 16 is dropped on the surface of the semiconductor device 10 vacuum-fixed to the spin head 21, and then the spin head 21 is rotated at high speed. Form the plating resist 16. At this time, if the semiconductor device 10 is warped, the vacuum leaks and the adsorption force is reduced. If this attractive force loses to the centrifugal force of the semiconductor device 10 rotating at high speed, the semiconductor device 10 will come off from the spin head 21 and be damaged.

【0011】

The second adverse effect is that abnormal gold deposition failure occurs on the back surface of the semiconductor device in the protrusion electrode forming process. As shown in FIG. 6, the projection electrode 17 is formed by electrolytic plating, and the plating electrode needle 23 is set up on the semiconductor device 10 installed on the plating jig 22. The plated electrode needle 23 penetrates the plated resist formed in the semiconductor device 10 and connects to the common electrode film.

【0012】

As shown in FIG. 7, the plating jig 22 installed in the semiconductor device 10 and the anode electrode 24 are arranged so as to face each other in the non-cyanide plating solution 25, and the current density is 0.1 to 0.5 A / dm.² A protruding electrode is formed by controlling with a plating power supply so as to become.

【0013】

When the concave warped semiconductor device 10 is installed on the plating jig 22, a gap is generated between the semiconductor device 11 and the plating jig 22, and the plating solution 22 wraps around the back surface of the semiconductor device 11 to form the semiconductor device. Gold is also deposited on the back surface of 10.

【0014】

The height dimension formed by the protrusion electrode 17 is calculated from the opening area of the plating resist 16 to control the height formed by the protrusion electrode 17. Therefore, depending on the amount of gold deposited on the back surface of the semiconductor device 10, an error occurs in the height formed by the protruding electrode 17, and an outer shape defect occurs.

【0015】

As described above, the concave warp of the semiconductor device has various shapes and adverse effects from the formation of the common electrode film to the step of removing the unnecessary common electrode film other than the protruding electrode portion.

【0016】

[Purpose of the Invention] An object of the present invention is to solve the above problems and to provide a method for manufacturing a semiconductor device having excellent mass productivity by reducing concave warpage of the semiconductor device.

【0017】

[Means for solving problems]

In order to solve the above object, the following means are adopted in the method for manufacturing a semiconductor device of the present invention.

【0018】

In the method for manufacturing a semiconductor device of the present invention, a step of forming a protective film on the surface of a semiconductor device having a connection electrode pad, which is an element forming surface, and patterning the protective film so that the electrode pad opens, and a common electrode A step of forming a film on the front surface of the semiconductor device, a step of forming a stress relief film on the back surface of the semiconductor device, a step of forming a plating resist on the surface of the semiconductor device, and a step of forming the plating resist so that the protrusion electrode forming region opens. A step of forming a protruding electrode by plating in the opening of the plating resist, a step of removing the plating resist, and a step of removing the common electrode film and the stress relaxation film of the portion other than the base of the protruding electrode. It is characterized by having and.

【0019】

In the method for manufacturing a semiconductor device of the present invention, a step of forming a protective film on the surface of the semiconductor device having a connection electrode pad, which is an element forming surface, and patterning the protective film so that the electrode pad opens, and stress relaxation. A step of forming a film on the back surface of the semiconductor device, a step of forming a common electrode film on the surface of the semiconductor device, a step of forming a plating resist on the entire surface of the semiconductor device, and a step of opening the plating resist on the protrusion electrode forming region. The step of patterning as described above, the step of forming a protruding electrode by plating in the opening of the plating resist, the step of removing the plating resist, and the step of removing the common electrode film and the stress relaxation film of the portion other than the base of the protruding electrode. It is characterized by having a process.

【0020】

[Action] The method for manufacturing a semiconductor device according to the present invention is characterized in that a stress relaxation film having the same film structure as a common electrode film arranged on the element forming surface of the semiconductor device is provided on the back surface of the semiconductor device. The stress of the common electrode film, which strongly affects the concave warp of the semiconductor device, is canceled by the stress of the stress relaxation film, and the concave warp of the semiconductor device can be reduced.

【0021】

It is possible to suppress adverse effects on the manufacturing process such as plating wraparound on the back surface of the semiconductor device and poor vacuum adsorption of the semiconductor device induced by the concave warp of the semiconductor device.

【0022】

In the present invention, it is possible to manufacture a semiconductor device having excellent mass productivity with less concave warpage of the semiconductor device even if the diameter of the semiconductor device (wafer) is increased and further reduced.

【0023】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a method of manufacturing a semiconductor device in the best mode for carrying out the present invention will be described with reference to the drawings. 1 to 5 and 7 are sectional views showing a manufacturing method of the semiconductor device of the present invention, and FIG. 6 is a plan view showing a manufacturing method of the semiconductor device of the present invention.

【0024】

A method for manufacturing a protruding electrode according to an embodiment of the present invention will be described. As shown in FIG. 1, the semiconductor device 10 is formed with a thickness of 1 μm in order to connect the connection electrode pad 12 made of aluminum to the outside on the element forming surface of the silicon substrate 11.

【0025】

Further, a protective film 13 for the purpose of protecting the semiconductor element is formed on the entire surface of the silicon substrate 11 including the connection electrode pad 12. The protective film 13 is generally formed by using an inorganic film such as a phosphorus-containing silicon oxide film or a silicon nitride film, an organic film such as a polyimide resin, or a laminated structure thereof, and the film thickness is 2 μm. After that, the protective film 13 is opened so that the connection electrode pad 12 is exposed by photosoligraphy and etching in which an exposure development process is performed using a predetermined mask.

【0026】

Next, a common electrode film 14 is sequentially formed on the entire surface of the silicon substrate 11 with a thickness of 0.8 μm for aluminum, 0.01 μm for chromium, and 0.8 μm for copper by a method such as a sputtering method or a vacuum vapor deposition method. ..

【0027】

As shown in FIG. 2, the stress relief film 15 having the same film structure as the common electrode film 14 is sequentially formed on the entire back surface of the silicon substrate 11 with a thickness of 0.8 μm for aluminum, 0.01 μm for chromium, and 0.8 μm for copper. Is formed by a method such as a sputtering method or a vacuum vapor deposition method.

【0028】

Next, as shown in FIG. 5, a plating resist 16 made of a thick film liquid photosensitive resist is applied to the entire surface of the silicon substrate 11. The coating method of the plating resist 16 is generally rotary coating. After dropping the plating resist 16 on the surface of the semiconductor device 10 vacuum-fixed to the spin head 21, the spin head 21 is rotated at high speed to thicken the plating resist 16. Form 20 μm.

【0029】

As shown in FIG. 3, an opening is provided in the plating resist 16 of the portion of the common electrode film 14 on the connection electrode pad 12 by photolithography in which an exposure development process is performed using a predetermined mask.

【0030】

Next, the protruding electrode 17 made of gold is formed by electroplating to a thickness of 15 μm. In the electrolytic plating method, as shown in FIG. 6, the plating electrode needle 23 is set up on the semiconductor device 10 installed on the plating jig 22. The plated electrode needle 23 penetrates the plated resist formed in the semiconductor device 10 and connects to the common electrode film.

【0031】

As shown in FIG. 7, the plating jig 22 installed in the semiconductor device 10 and the anode electrode 24 are arranged so as to face each other in the non-cyanide plating solution 25, and the current density is 0.1 to 0.5 A / dm.² A protruding electrode is formed by controlling with a plating power supply so as to become.

【0032】

As shown in FIG. 4, the plating resist 16 that is no longer needed is removed with a resist stripping solution. Further, the common electrode film 14 and the stress relaxation film 15 other than the base portion of the protruding electrode 17 are removed. Copper, which is the upper layer metal of both the common electrode film 14 and the stress relaxation film 15, is removed by etching with Meltex's copper etching solution Enstrip C (trade name).

【0033】

Next, chromium of the middle metal of the common electrode film 14 and aluminum of the lower metal are etched and removed with a mixed solution of ammonium cerium nitrate, potassium ferricyanide and sodium hydroxide.

【0034】

In the method for manufacturing a semiconductor device according to the present invention, a method of forming a stress relaxation film having the same configuration as the common electrode film on the back surface of the semiconductor device for the purpose of canceling the stress of the common electrode film that causes the concave warp of the semiconductor device. It was adopted. In the manufacturing method of the prior art, the warp of the concave semiconductor device measured after forming the common electrode film on a 5-inch wafer having a thickness of 620 μm was 120 μm. In the method for manufacturing a semiconductor device according to the present invention, the amount of warpage of a concave semiconductor device can be reduced to 50 μm, which is less than half that of the conventional method.

【0035】

As a result, the semiconductor device is damaged due to poor vacuum adsorption in the plating resist forming process, and the plating solution in the gap between the plating jig and the semiconductor device in the protruding electrode forming process, which has been a problem in the manufacturing method of the prior art. Abnormal precipitation of gold due to wraparound has been eliminated, and it has become possible to provide a method for manufacturing a semiconductor device having excellent mass productivity.

【0036】

An embodiment of the present invention has been described by taking a common electrode film having a film structure of aluminum, chromium, and copper as an example. However, a metal multilayer film of aluminum, titanium, and copper, a metal multilayer film of titanium-palladium, and titanium and gold have been described. Metal multilayer film, titanium-platinum metal multilayer film, titanium-tungsten alloy and baradium metal multilayer film, titanium-tungsten alloy and gold metal multilayer film, titanium-tungsten alloy and platinum metal multilayer film, etc. It can also be applied to a common electrode film using.

【0037】

Further, the embodiment of the present invention has been described by the manufacturing method in the order of common electrode film formation and stress relaxation film formation, but the same effect can be obtained by adopting the manufacturing method in the order of stress relaxation film formation and stress relaxation film formation. can get. Further, since the same effect can be obtained even if the common electrode film and the stress relaxation film do not have exactly the same configuration, the film thickness of the stress relaxation film is selected according to the size and thickness of the semiconductor device (wafer) and the semiconductor device. It is possible to almost eliminate the concave warp of the.

【0038】

[Effect of the invention]

As is clear from the above description, the method for manufacturing a semiconductor device according to the present invention is characterized in that a stress relaxation film having the same film structure as the common electrode film arranged on the element forming surface of the semiconductor device is installed on the back surface of the semiconductor device. It is said.

【0039】

As a result, the stress of the common electrode film, which strongly affects the concave warp of the semiconductor device, is canceled by the stress of the stress relaxation film, and the concave warp of the semiconductor device can be reduced. As a result, it is possible to suppress adverse effects on the manufacturing process such as plating wraparound on the back surface of the semiconductor device and poor vacuum adsorption of the semiconductor device, which are induced by the concave warp of the semiconductor device.

【0040】

In the present invention, it is possible to manufacture a semiconductor device having excellent mass productivity with less concave warpage of the semiconductor device even if the diameter of the semiconductor device (wafer) is increased and further reduced.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing which shows the manufacturing method of the semiconductor device in embodiment of this invention.

[Figure 2]

It is a top view which shows the manufacturing method of the semiconductor device in embodiment of this invention.

[Fig. 3]

It is a top view which shows the manufacturing method of the semiconductor device in embodiment of this invention.

[Fig. 4]

It is sectional drawing which shows the manufacturing method of the semiconductor device in embodiment of this invention.

[Fig. 5]

It is sectional drawing for demonstrating the manufacturing method of the semiconductor device in embodiment of this invention and the prior art.

[Fig. 6]

It is a plane for demonstrating the manufacturing method of the semiconductor device in embodiment of this invention and the prior art.

[Fig. 7]

It is sectional drawing for demonstrating the manufacturing method of the semiconductor device in embodiment of this invention and the prior art.

[Fig. 8]

It is sectional drawing which shows the semiconductor device for demonstrating the prior art.

[Fig. 9]

It is sectional drawing which shows the semiconductor device for demonstrating the prior art.

[Fig. 10]

It is sectional drawing which shows the semiconductor device for demonstrating the prior art.

[Explanation of symbols]

10: Semiconductor device 11: Silicon substrate 12: Connection electrode pad 13: Protective film 14: Common electrode film 15: Stress relaxation film 16: Plating resist 17: Projection electrode