Apparatus and methods for alignment of a susceptor

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application claims benefit of U.S. Provisional Patent Application Ser. No.: 62/023,625 (Attorney Docket No. 022007USAL) filed Jul. 11, 2014, and U.S. Provisional Patent Application Ser. No.: 62/039,210 (Attorney Docket No. 022007USAL02) filed Aug. 19, 2014, both applications are hereby incorporated by reference herein.

BACKGROUND

00021. Field

0003Embodiments disclosed herein generally relate to semiconductor processing and more specifically to a method and apparatus for aligning a susceptor in a thermal processing chamber.

00042. Description of the Related Art

0005Thermal processing chambers, such as rapid thermal processing (RTP) and epitaxial chambers are employed in semiconductor chip fabrication to create, chemically alter, or etch surface structures on semiconductor substrates. RTP and epitaxial chambers typically heat the substrate using an array of high-intensity lamps. The lamps heat the substrate to temperatures up to or exceeding about 1,000 degrees Celsius in a short period of time. The substrate may then be cooled in the chamber in a short time period when the lamps are powered off. The chambers are typically made of quartz to withstand the high temperature as well as the temperature changes. The large temperature range experienced by the chamber causes significant thermal expansion and contraction. Loose tolerances between parts are generally required with quartz materials to enable the thermal expansion which makes precise alignment of chamber components difficult.

0006Precise alignment of a susceptor, or substrate support, within the chamber is difficult. The typical desired position of the susceptor is to center the susceptor in an X-Y plane of the chamber as well as having the substrate receiving surface of the susceptor parallel to the X-Y plane of the chamber. However, due to design constraints in conventional systems, the susceptor is not reliably placed at the desired position and orientation, which may create multiple processing issues. For example, in conventional systems, it may be chosen to center the susceptor in the X-Y plane, which may result in the susceptor being disposed in a plane that is not parallel (i.e., tilted) relative to the X-Y plane of the chamber. Susceptor tilt will most likely not be the same in multiple chambers, which produces numerous chamber matching issues including pyrometer error, actual temperature differences, gas flow differences, boundary layer effects, wafer sliding, among others.

0007Thus, there is a need for an apparatus and method enabling more precise alignment of a susceptor in a thermal processing chamber.

SUMMARY

0008The embodiments described herein generally relate to methods and apparatus for aligning a susceptor in a thermal processing chamber, such as an epitaxial deposition chamber or a rapid thermal processing chamber, among other chambers utilized to thermally process substrates.

0009In one embodiment, a thermal processing chamber is provided. The thermal process chamber includes a susceptor, a stem coupled to the susceptor, and a motion assembly coupled to the stem, the motion assembly comprising a lateral adjustment device and a tilt adjustment mechanism adapted to position a major surface of the susceptor in plane that is parallel to an X-Y plane of the chamber and position the stem along a longitudinal axis of the chamber.

0010In another embodiment, a thermal processing chamber is provided. The thermal process chamber includes a susceptor, a stem coupled to the susceptor, and a motion assembly coupled to the stem, the motion assembly comprising a lateral adjustment device and a tilt adjustment mechanism adapted to position a major surface of the susceptor in plane that is parallel to an X-Y plane of the chamber and position the stem along a longitudinal axis of the chamber, wherein the motion assembly comprises at least two flexible seals, and wherein the lateral adjustment device comprises an X adjustment plate and a Y adjustment plate that are coupled to adjacent sides of a base plate disposed adjacent to one of the at least two flexible seals.

0011In another embodiment, a stem assembly for coupling a susceptor to a process chamber is provided. The stem assembly includes a pivot mechanism having a stem disposed therethrough, a vertical actuator coupled to the stem, a rotary actuator disposed in a housing coupled to the stem, a first flexible seal coupled between the pivot mechanism and a bracket of the vertical actuator, a second flexible seal coupled to the bracket and a base plate of the rotary actuator, and a motion assembly adapted to move the housing in an X axis, a Y axis and position the susceptor angularly relative to an X-Y plane of the process chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

0012So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

0013<figref idref="DRAWINGS">FIG. 1</figref> illustrates a schematic sectional view of a thermal processing chamber.

0014<figref idref="DRAWINGS">FIG. 2</figref> is a side cross-sectional view of a portion of the process chamber of <figref idref="DRAWINGS">FIG. 1</figref> showing one embodiment of a motion assembly.

0015<figref idref="DRAWINGS">FIG. 3</figref> is an exploded isometric view of one embodiment of an adjustment portion of the motion assembly of <figref idref="DRAWINGS">FIG. 2</figref>.

0016<figref idref="DRAWINGS">FIGS. 4A and 4B</figref> are schematic cross-sectional views showing one embodiment of an installation and alignment procedure of a susceptor.

0017<figref idref="DRAWINGS">FIGS. 5A-5C</figref> are schematic cross-sectional views showing another embodiment of an installation and alignment procedure of a susceptor.

0018To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

0019Embodiments disclosed herein generally relate to methods and apparatus for aligning a susceptor in a thermal processing chamber, such as an epitaxial deposition chamber or a rapid thermal processing chamber, among other chambers utilized to thermally process substrates.

0020<figref idref="DRAWINGS">FIG. 1</figref> illustrates a schematic sectional view of a thermal processing chamber <b>100</b> according to one embodiment. The thermal processing chamber <b>100</b> may be used as an epitaxial deposition chamber, a rapid thermal processing chamber, or other thermal treatment chamber. The process chamber <b>100</b> may be used to process one or more substrates, including the deposition of a material on an upper surface of a substrate <b>102</b>, heating of a substrate <b>102</b>, etching of a substrate <b>102</b>, or combinations thereof. The process chamber <b>100</b> generally includes an array of radiant heating lamps <b>104</b> for heating, among other components, a susceptor <b>106</b> disposed within the process chamber <b>100</b>. The susceptor <b>106</b> may be a disk-like substrate support as shown, or may be a ring-like substrate support (not shown), which supports the substrate from the edge of the substrate, which exposes a backside of the substrate <b>102</b> to heat from the radiant heating lamps <b>104</b>. The susceptor <b>106</b> may be formed from silicon carbide or graphite coated with silicon carbide to absorb radiant energy from the lamps <b>104</b> and conduct the radiant energy to the substrate <b>102</b>, thereby heating the substrate <b>102</b>.

0021The susceptor <b>106</b> is located within the process chamber <b>100</b> between an upper dome <b>108</b> and a lower dome <b>110</b>. The upper dome <b>108</b> and the lower dome <b>110</b>, along with a base ring <b>112</b> that is disposed between the upper dome <b>108</b> and lower dome <b>110</b>, generally define an internal region <b>111</b> of the process chamber <b>100</b>. The substrate <b>102</b> can be transferred into the process chamber <b>100</b> and positioned onto the susceptor <b>106</b> through a loading port (not shown) formed in the base ring <b>112</b>. A process gas inlet <b>114</b> and a gas outlet <b>116</b> may be provided in the base ring <b>112</b>.

0022The susceptor <b>106</b> includes a shaft or stem <b>118</b> that is coupled to a motion assembly <b>120</b>. The motion assembly <b>120</b> includes one or more actuators and/or adjustment devices that provide movement and/or adjustment of the stem <b>118</b> and/or the susceptor <b>106</b> within the internal region <b>111</b>. For example, the motion assembly <b>120</b> may include a rotary actuator <b>122</b> that rotates the susceptor <b>106</b> about a longitudinal axis A of the process chamber <b>100</b>. The longitudinal axis A may include a center of an X-Y plane of the process chamber <b>100</b>. The motion assembly <b>120</b> may include a vertical actuator <b>124</b> to lift and lower the susceptor <b>106</b> in the Z direction. The motion assembly <b>120</b> may include a tilt adjustment device <b>126</b> that is used to adjust a planar orientation of the susceptor <b>106</b> in the internal region <b>111</b>. The motion assembly <b>120</b> may also include a lateral adjustment device <b>128</b> that is utilized to adjust the positioning of the stem <b>118</b> and/or the susceptor <b>106</b> side to side within the internal region <b>111</b>. In embodiments where one or both of the following is necessary, the lateral adjustment device <b>128</b> is utilized to adjust positioning of the stem <b>118</b> and/or the susceptor <b>106</b> in the X and/or Y direction while the tilt adjustment device <b>126</b> adjusts an angular orientation (α) of the stem <b>118</b> and/or the susceptor <b>106</b>. In one embodiment, the motion assembly <b>120</b> includes a pivot mechanism <b>130</b>. As the lower dome <b>110</b> is rigidly fixed to the process chamber <b>100</b> by the base ring <b>112</b>, the pivot mechanism <b>130</b> is utilized to allow the motion assembly <b>120</b> to move the stem <b>118</b> and/or the susceptor <b>106</b> at least in the angular orientation (α) to reduce stresses on the lower dome <b>110</b>.

0023The susceptor <b>106</b> is shown in an elevated processing position but may be lifted or lowered vertically by the motion assembly <b>120</b> as described above. The susceptor <b>106</b> may be lowered to a transfer position (below the processing position) to allow lift pins <b>132</b> to contact the lower dome <b>110</b>. The lift pins <b>132</b> are disposed in holes in the susceptor <b>106</b> and as the susceptor <b>106</b> is lowered, the lift pins <b>132</b> raise the substrate <b>102</b> from the susceptor <b>106</b>. A robot (not shown) may then enter the process chamber <b>100</b> to engage and remove the substrate therefrom though the loading port. A new substrate <b>102</b> may be loaded onto the lift pins <b>132</b> by the robot, and the susceptor <b>106</b> may then be actuated up to the processing position to place the substrate <b>102</b>, with its device side <b>150</b> facing up. The lift pins <b>132</b> include an enlarged head allowing the lift pins <b>132</b> to be suspended in openings by the susceptor <b>106</b> in the processing position. In one embodiment, stand-offs <b>134</b> coupled to the lower dome <b>110</b> are utilized to provide a flat surface for the lift pins <b>132</b> to contact. The stand-offs provide a surface that is parallel to the X-Y plane of the process chamber <b>100</b> and may be used to prevent binding of the lift pins <b>132</b> that may occur if the end thereof is allowed to contact the curved surface of the lower dome <b>110</b>. The stand-offs <b>134</b> may be made of an optically transparent material to allow energy from the lamps <b>104</b> to pass therethrough.

0024The susceptor <b>106</b>, while located in the processing position, divides the internal volume of the process chamber <b>100</b> into a process gas region <b>136</b> that is above the susceptor <b>106</b>, and a purge gas region <b>138</b> below the susceptor <b>106</b>. The susceptor <b>106</b> is rotated during processing by the rotary actuator <b>122</b> to minimize the effect of thermal and process gas flow spatial anomalies within the process chamber <b>100</b> and thus facilitates uniform processing of the substrate <b>102</b>. The susceptor <b>106</b> is supported by the stem <b>118</b>, which is generally centered on the susceptor <b>106</b> and facilitates movement of the susceptor <b>106</b> substrate <b>102</b> in a vertical direction (Z direction) during substrate transfer, and in some instances, processing of the substrate <b>102</b>.

0025In general, the central window portion of the upper dome <b>108</b> and the bottom of the lower dome <b>110</b> are formed from an optically transparent material such as quartz. The thickness and the degree of curvature of the upper dome <b>108</b> may be configured to provide a flatter geometry for uniform flow uniformity in the process chamber.

0026One or more lamps, such as an array of the radiant heating lamps <b>104</b>, can be disposed adjacent to and beneath the lower dome <b>110</b> in a specified manner around the stem <b>118</b>. The radiant heating lamps <b>104</b> may be independently control or controlled in zones in order to control the temperature of various regions of the substrate <b>102</b> as the process gas passes thereover, thereby facilitating the deposition of a material onto the upper surface of the substrate <b>102</b>. While not discussed here in detail, the deposited material may include silicon, doped silicon, germanium, doped germanium, silicon germanium, doped silicon germanium, gallium arsenide, gallium nitride, or aluminum gallium nitride.

0027The radiant heating lamps <b>104</b> may include a radiant heat source, depicted here as a lamp bulb <b>141</b>, and may be configured to heat the substrate <b>102</b> to a temperature within a range of about 200 degrees Celsius to about 1,600 degrees Celsius. Each lamp bulb <b>141</b> can be coupled to a standoff a power distribution board, such as printed circuit board (PCB) <b>152</b>, through which power is supplied to each lamp bulb <b>141</b>. In one embodiment, the radiant heating lamps <b>104</b> are positioned within a lamphead <b>145</b> which may be cooled during or after processing.

0028A circular shield <b>146</b> may be optionally disposed around the susceptor <b>106</b> and coupled to sidewall of the chamber body <b>148</b>. The shield <b>146</b> prevents or minimizes leakage of heat/light noise from the lamps <b>104</b> to the device side <b>150</b> of the substrate <b>102</b> in addition to providing a pre-heat zone for the process gases. The shield <b>146</b> may be made from CVD SiC, sintered graphite coated with SiC, grown SiC, opaque quartz, coated quartz, or any similar, suitable material that is resistant to chemical breakdown by process and purge gases. In some embodiments, the shield <b>146</b> is coupled to a liner <b>163</b> disposed on the base ring <b>112</b>.

0029Substrate temperature is provided by sensors configured to measure temperatures at the bottom of the susceptor <b>106</b>. The sensors may be pyrometers (not shown) disposed in ports formed in the lamphead <b>145</b>. Additionally or alternatively, one or more sensors <b>152</b>, such as a pyrometer, may be directed to measure the temperature of the device side <b>150</b> of the substrate <b>102</b>. A reflector <b>154</b> may be optionally placed outside the upper dome <b>108</b> to reflect infrared light that is radiating off the substrate <b>102</b> and redirect the energy back onto the substrate <b>102</b>. The reflector <b>154</b> may be secured to the upper dome <b>108</b> using a clamp ring <b>156</b>. The reflector <b>154</b> can be made of a metal such as aluminum or stainless steel.

0030Process gas supplied from a process gas supply source <b>172</b> is introduced into the process gas region <b>136</b> through the process gas inlet <b>114</b> formed in the sidewall of the base ring <b>112</b>. The process gas inlet <b>114</b> is configured to direct the process gas in a generally radially inward direction. During a film formation process, the susceptor <b>106</b> is located in the processing position, which is adjacent to and at about the same elevation as the process gas inlet <b>114</b>, thus allowing the process gas to flow generally along flow path <b>173</b> across the upper surface of the substrate <b>102</b>. The process gas exits the process gas region <b>136</b> (along flow path <b>175</b>) through the gas outlet <b>116</b> located on the opposite side of the process chamber <b>100</b> as the process gas inlet <b>114</b>. Removal of the process gas through the gas outlet <b>116</b> may be facilitated by a vacuum pump <b>180</b> coupled thereto.

0031Purge gas supplied from a purge gas source <b>162</b> is introduced to the purge gas region <b>138</b> through a purge gas inlet <b>164</b> formed in the sidewall of the base ring <b>112</b>. The purge gas inlet <b>164</b> is disposed at an elevation below the process gas inlet <b>114</b>. If the circular shield <b>146</b> is used, the circular shield <b>146</b> may be disposed between the process gas inlet <b>114</b> and the purge gas inlet <b>164</b>. In either case, the purge gas inlet <b>164</b> is configured to direct the purge gas in a generally radially inward direction. If desired, the purge gas inlet <b>164</b> may be configured to direct the purge gas in an upward direction. During a film formation process, the susceptor <b>106</b> is located at a position such that the purge gas flows generally along flow path <b>165</b> across a back side of the susceptor <b>106</b>. The purge gas exits the purge gas region <b>138</b> (along flow path <b>166</b>) and is exhausted out of the process chamber through the gas outlet <b>116</b> located on the opposite side of the process chamber <b>100</b> as the purge gas inlet <b>164</b>.

0032<figref idref="DRAWINGS">FIG. 2</figref> is a side cross-sectional view of a portion of the process chamber <b>100</b> of <figref idref="DRAWINGS">FIG. 1</figref> showing one embodiment of a motion assembly <b>200</b>. The motion assembly <b>200</b> may be used as the motion assembly <b>120</b> of <figref idref="DRAWINGS">FIG. 1</figref>. The motion assembly <b>200</b> includes a pivot mechanism <b>130</b> which allows a movable portion <b>205</b>, which is operably coupled to the stem <b>118</b>, to move at least angularly relative to the lower dome <b>110</b>. Dynamic seals <b>206</b>, which may be an elastomeric o-ring, may be coupled between an outer housing <b>207</b> and an inner portion <b>208</b> of the lower dome <b>110</b>. The movable portion <b>205</b> includes the rotary actuator <b>122</b> that is coupled to a rotary stage <b>210</b> disposed in a housing <b>212</b>. In some embodiments, the rotary stage <b>210</b> is operably coupled to the stem <b>118</b> by a tube <b>214</b>. The rotary stage <b>210</b> may be coupled to the tube <b>214</b> by a magnetic coupling. The tube <b>214</b> includes an inner dimension sized to receive an outer diameter of the stem <b>118</b>. The tube <b>214</b> captures and vertically supports the stem <b>118</b>. The tube <b>214</b> and/or the stem <b>118</b> may include fasteners or indexing features (i.e., flats, grooves, and the like) that facilitate positive engagement therebetween to facilitate rotation of the stem <b>118</b> based on rotation of the rotary stage <b>210</b>.

0033The movable portion <b>205</b> also includes a vertical actuator <b>124</b>, which may include a rotary motor <b>216</b> that is operably coupled to the stem <b>118</b>. In one embodiment, the vertical actuator <b>124</b> includes a screw drive <b>218</b> coupled to the rotary motor <b>216</b> and one or more brackets <b>220</b> that are coupled to the stem <b>118</b>. The bracket(s) <b>220</b> may be coupled to the tube <b>214</b> when the tube <b>214</b> is used. Rotation of the screw drive <b>218</b> raises or lowers the stem <b>118</b> (having the susceptor <b>106</b> (shown in <figref idref="DRAWINGS">FIG. 1</figref>) coupled thereto) in the Z direction. A first flexible seal <b>222</b>, such as a bellows, may be disposed between a base <b>224</b> of the vertical actuator <b>124</b> and the one or more brackets <b>220</b>.

0034The motion assembly <b>200</b> also includes an adjustment portion <b>226</b> operably coupled to one or more components of the movable portion <b>205</b>. The adjustment portion <b>226</b> includes the lateral adjustment device <b>128</b> and the tilt adjustment device <b>126</b>. The adjustment portion <b>226</b> also includes a second flexible seal <b>228</b>, such as a bellows. The second flexible seal <b>228</b> is adapted to move independently of the first flexible seal <b>222</b>, and vice-versa. The second flexible seal <b>228</b> allows all components within the motion assembly <b>200</b> to share the same environment as the purge gas region <b>138</b> of the process chamber <b>100</b> up to the rotary stage <b>210</b>, in one embodiment. Thus, a reduced pressure environment may be contained in the motion assembly <b>200</b> while the rotary stage <b>210</b> is in ambient pressures. The second flexible seal <b>228</b> may terminate at a base plate <b>230</b> of the housing <b>212</b> of the rotary stage <b>210</b>.

0035The lateral adjustment device <b>128</b> and the tilt adjustment device <b>126</b> may comprise a manual adjustment apparatus for centering of the stem <b>118</b> as well as adjusting planarity and/or tilt of the stem <b>118</b> and the susceptor <b>106</b> coupled thereto. In some embodiments, the vertical actuator <b>124</b> includes a bracket <b>225</b> that extends vertically from the base <b>224</b>. The bracket <b>225</b> may be integral to the vertical actuator <b>124</b> and may be substantially parallel to a longitudinal axis of the stem <b>118</b>. Substantially parallel as used herein includes parallel (e.g., 0 degrees relative to the longitudinal axis A) as well as a +/−5 degree angle, or less, relative to the longitudinal axis A. The tilt adjustment device <b>126</b> may move the base <b>224</b> laterally in the X and/or the Y direction by pushing or pulling on the bracket <b>225</b>, which may be used to adjust the tilt of the stem <b>118</b> and/or the planarity of the susceptor <b>106</b>. The tilt adjustment device <b>126</b> may be an actuator, a screw, or other adjustable fastener that pushes or pulls on the bracket <b>225</b>. In one embodiment, the lateral adjustment device <b>128</b> may include an X adjustment plate <b>232</b> that is coupled to the base plate <b>230</b> by a fastener <b>234</b>, such as by a bolt or screw. The base plate <b>230</b> may be disposed at an angle that is substantially normal to the stem <b>118</b> and/or parallel to a plane of a surface of the susceptor <b>106</b> (shown in <figref idref="DRAWINGS">FIG. 1</figref>), and the X adjustment plate <b>232</b> may be disposed at an angle that is substantially normal to a plane of the base plate <b>230</b> and/or the rotational axis of the stem <b>118</b>. Substantially normal as used herein includes 90 degrees as well as +/−5 degrees, or less.

0036The X adjustment plate <b>232</b> includes an adjustment feature <b>236</b>, which may be a set screw that contacts a surface of the housing <b>212</b> of the rotary stage <b>210</b>. The adjustment feature <b>236</b> may push and/or pull the housing <b>212</b> to displace the housing <b>212</b> in the X direction. The displacement of the housing <b>212</b> is utilized to center the stem <b>118</b> relative to the lower dome <b>110</b> and/or center the susceptor <b>106</b> relative to the circular shield <b>146</b> (shown in <figref idref="DRAWINGS">FIG. 1</figref>). While not shown in this view, a Y adjustment plate may be coupled to the base plate <b>230</b> and operates similar to the X adjustment plate <b>232</b> except for providing displacement in the Y direction. When the stem <b>118</b> is out of alignment with the longitudinal axis A, which may cause the susceptor <b>106</b> to tilt, the tilt adjustment device <b>126</b> may be utilized to correct the tilt of the susceptor <b>106</b>. The displacement of the housing <b>212</b> may be limited to the portion of the motion assembly <b>200</b> below the base plate <b>230</b> which allows the first flexible seal <b>222</b> to remain on-axis (i.e., centered about the stem <b>118</b>). Any transverse displacement in the assembly is accommodated by the second flexible seal <b>228</b> which moves in the X and/or Y direction while the first flexible seal <b>222</b> remains substantially parallel to the longitudinal axis A. Thus, expansion and contraction of the second flexible seal <b>228</b> is limited or non-existent, which reduces fatigue and extends the lifetime of the second flexible seal <b>228</b>. In some embodiments, the first flexible seal <b>222</b> is substantially limited to movement along the longitudinal axis A of the process chamber <b>100</b> while the second flexible seal <b>228</b> is substantially limited to lateral movement (in the X and Y directions) of the process chamber <b>100</b>. Substantially limited in movement as used herein includes no movement as well as movement within 5 millimeters, or less.

0037<figref idref="DRAWINGS">FIG. 3</figref> is an exploded isometric view of one embodiment of an adjustment portion <b>300</b> of the motion assembly <b>200</b> of <figref idref="DRAWINGS">FIG. 2</figref>. The adjustment portion <b>300</b> includes the X adjustment plate <b>232</b> that is adapted to couple to the base plate <b>230</b> using one or more fasteners <b>234</b>. A Y adjustment plate <b>305</b> may also be coupled to the base plate <b>230</b> at a substantially orthogonal angle relative to the X adjustment plate <b>232</b> using one or more fasteners <b>234</b>. Both of the X adjustment plate <b>232</b> and the Y adjustment plate <b>305</b> include at least one adjustment feature <b>236</b> that contacts a surface <b>310</b> of the housing <b>212</b>. The adjustment feature <b>236</b> may be rotated toward or away from the housing <b>212</b> for transverse adjustment of the housing <b>212</b> and the stem <b>118</b> (shown in <figref idref="DRAWINGS">FIG. 2</figref>) in order to center the stem <b>118</b> in the X-Y plane of the process chamber <b>100</b> (shown in <figref idref="DRAWINGS">FIG. 1</figref>).

0038The adjustment features <b>236</b> utilized on the X adjustment plate <b>232</b> and the Y adjustment plate <b>305</b> may be a set screw that is rotated against the surfaces <b>310</b> of the housing <b>212</b> and pushes the housing <b>212</b> away from a respective plate <b>232</b> or <b>305</b>, in one embodiment. In another embodiment, the adjustment features <b>236</b> may engage the surfaces <b>310</b> such that rotation of the adjustment features <b>236</b> pulls the housing <b>212</b> toward a respective plate <b>232</b> or <b>305</b>.

0039<figref idref="DRAWINGS">FIGS. 4A and 4B</figref> are schematic cross-sectional views showing one embodiment of an installation and alignment procedure <b>400</b> of a susceptor <b>106</b>. The installation and alignment procedure <b>400</b> includes an initial installation of the susceptor <b>106</b>. The susceptor <b>106</b> may be inserted into the tube <b>214</b> (shown in <figref idref="DRAWINGS">FIG. 2</figref>) and coupled to the rotary stage <b>210</b> within the housing <b>212</b> by a magnetically-coupled drive assembly. As shown in <figref idref="DRAWINGS">FIG. 4A</figref>, the susceptor <b>106</b> is off-center (i.e., misaligned in X-Y). As shown in <figref idref="DRAWINGS">FIG. 4B</figref>, the adjustment feature <b>236</b> provided in a bracket <b>405</b> moves the housing <b>212</b> in the X direction, which moves the stem <b>118</b> and the susceptor <b>106</b> in the X direction thereby substantially centering the stem <b>118</b> and the susceptor <b>106</b> relative to the circular shield <b>146</b>. While not shown, the stem <b>118</b> and the susceptor <b>106</b> may be adjusted in the Y direction if needed.

0040<figref idref="DRAWINGS">FIGS. 5A-5C</figref> are schematic cross-sectional views showing another embodiment of an installation and alignment procedure <b>500</b> of a susceptor <b>106</b>. The installation and alignment procedure <b>500</b> includes an initial installation of the susceptor <b>106</b> in the stem assembly similar to <figref idref="DRAWINGS">FIG. 4A</figref>, except the stem <b>118</b> and the susceptor <b>106</b> are tilted relative to the longitudinal axis A and the X-Y plane, respectively, as shown in <figref idref="DRAWINGS">FIG. 5A</figref>.

0041<figref idref="DRAWINGS">FIG. 5B</figref> shows a tilt correction provided by the tilt adjustment device <b>126</b>. The tilt adjustment device <b>126</b> is utilized to push against the bracket <b>405</b> which alleviates the tilt of the susceptor <b>106</b>. Thus, one or both major surfaces <b>505</b>A, <b>505</b>B of the susceptor <b>106</b> may be parallel to the X-Y plane, which provides uniform processing of a substrate (as opposed to a tilted susceptor) which reduces chamber matching problems, among other processing issues.

0042<figref idref="DRAWINGS">FIG. 5C</figref> shows a transverse alignment correction provided by the lateral adjustment device <b>128</b>, which generally centers the susceptor <b>106</b> relative to the circular shield <b>146</b>.

0043Embodiments of the tilt adjustment device <b>126</b> and the lateral adjustment device <b>128</b> provide more precise alignment and/or positioning of a susceptor <b>106</b> in a process chamber. The embodiments disclosed herein provide positioning of a susceptor that may be aligned simultaneously in tilt and centering. The positioning is achieved by providing separate actuation of the tilt alignment and the centering alignment. According to the embodiments, four degrees of freedom in alignment control are provided, such as tilt correction along the X-axis, tilt correction along the Y-axis, translation along the X-axis, and translation along the Y-axis. Correction of tilt may move the entire assembly (i.e., X and Y alignment devices, Z motion alignment and rotation devices). The centering and tilt correction provided by the embodiments reduces chamber matching issues, among other processing non-uniformities. The second flexible seal <b>228</b> may be adapted to move only in X and/or Y directions while the first flexible seal <b>222</b> moves primarily in the vertical (Z) direction. This differs from conventional susceptor assemblies where a single bellows assembly (which may be a bellows device coupled directly to and extending from another bellows device) is typically utilized such that the entire assembly is subject to tilt and multiple cycles of expansion and contraction. However, the first flexible seal <b>222</b> and the separate second flexible seal <b>228</b> limits fatigue of the seals by reducing transverse displacement in the first flexible seal <b>222</b> and reducing expansive/contractive movement in the second flexible seal <b>228</b>.

0044Tilting of the stem <b>118</b> and/or the susceptor <b>106</b> may be inherent due to multiple tolerances when assembling dozens of parts together in the construction of the thermal processing chamber <b>100</b>. The inner portion <b>208</b> of the lower dome <b>110</b> within the pivot mechanism <b>130</b> has no vertical reference. Hence, the tilt adjustment device <b>126</b> is utilized to correct this tilt that may be caused by the tolerances of the parts when assembled. In one embodiment, correction of the tilt may be carried out by using the tilt adjustment device <b>126</b> before any lateral correction is provided. Then centering of the susceptor <b>106</b> (pure X-Y) relative to the circular shield <b>146</b> may be performed using the lateral adjustment device <b>128</b>. Although not impossible, it has been determined that it is difficult to perform X-Y adjustments before tilt adjustment because tilt adjustment affects X-Y centering while X-Y centering does not affect tilt.

0045While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.