Susceptor support

Abstract

To provide a chemical vapor deposition (CVD) device that provides uniform heating for a susceptor support for supporting a substrate by eliminating arbitrary ununiformity in radiation in an energy source.SOLUTION: A susceptor support 150 supporting a susceptor 105 supporting a substrate 108 in a processing chamber 100 includes a shaft 170, a plate 172 with a first major surface coupled to the shaft, and a support element 174 extending from a second major surface 173 of the plate. The plate may be made of a material that is optically transparent to the radiation energy from a plurality of energy sources 102 disposed below the plate. The plate may have a thickness that is small enough to minimize radiation transmission loss and large enough to be thermally and mechanically stable to support the susceptor during processing. The thickness of the plate may range from about 2 to about 20 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Disclosed herein is an apparatus for semiconductor processing. More specifically, embodiments disclosed herein relate to a susceptor support for supporting a susceptor in a deposition process. [Background technology]

[0002] In the manufacture of integrated circuits, deposition processes such as chemical vapor deposition (CVD) or epitaxy processes are used to deposit films of various materials on semiconductor substrates. Epitaxy is a process widely used in semiconductor processing to form very thin layers of material on semiconductor substrates. These layers often define some of the smallest features of the semiconductor devices and can have high quality crystal structures if the electrical properties of crystalline materials are desired. Typically, deposition precursors are delivered to a processing chamber in which the substrate is located, and the substrate is heated to a temperature favorable for the growth of a material layer with specific properties.

[0003] Conventionally, the substrate is placed on a susceptor, which is supported by three or more arms extending from a shaft. A number of energy sources, such as lamps, may be placed below the substrate to heat the backside of the substrate. The susceptor is typically used to eliminate any non-uniformity in the radiation from the energy source. The radiation from the energy source is blocked by the arms of the susceptor support, resulting in non-uniformity that cannot be adequately eliminated by the susceptor, resulting in non-uniform heating of the susceptor.

[0004] Therefore, there is a need for an improved apparatus for supporting a susceptor. Summary of the Invention

[0005] Embodiments disclosed herein relate to a susceptor support for supporting a susceptor in a deposition process. In one embodiment, the apparatus includes a shaft and a plate having a first major surface coupled to the shaft. The plate includes quartz, fused silica, alumina, sapphire, or yttria, and the plate has a thickness within a range from about 2 mm to about 20 mm. The apparatus further includes a support element extending from a second major surface of the plate.

[0006] In another embodiment, an apparatus includes a shaft and a plate having a first major surface coupled to the shaft, the plate comprising quartz, fused silica, alumina, sapphire, or yttria, the apparatus further includes a support element extending from a second major surface of the plate, the support element having a height within a range from about 30 mm to about 60 mm.

[0007] In another embodiment, a processing chamber includes a first enclosure member, a second enclosure member, and a susceptor support. At least a portion of the susceptor support is disposed between the first enclosure member and the second enclosure member. The susceptor support includes a shaft and a plate having a first major surface coupled to the shaft. The plate includes quartz, fused silica, alumina, sapphire, or yttria, and the plate has a thickness within a range of about 2 mm to about 20 mm. The apparatus further includes a support element extending from the second major surface of the plate. The processing chamber further includes a plurality of energy sources disposed facing the second enclosure member.

[0008] So that the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, will be obtained by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure is open to other equally effective embodiments, and therefore, that the accompanying drawings illustrate only typical embodiments of the present disclosure, and should not be considered as limiting the scope of the present disclosure. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of a processing chamber according to one embodiment described herein. [Figure 2A] FIG. 2 is a perspective view of a susceptor support according to one embodiment described herein. [Figure 2B] 2B is a schematic cross-sectional view of the susceptor support of FIG. 2A. [Figure 2C] 1 is a schematic cross-sectional view of a support element according to one embodiment described herein. [Figure 2D] 1 is a schematic cross-sectional view of a support element according to one embodiment described herein. [Figure 2E] 1 is a schematic cross-sectional view of a support element according to one embodiment described herein. [Figure 3A] FIG. 2 is a perspective view of a susceptor support according to another embodiment described herein. [Figure 3B] FIG. 2 is a perspective view of a susceptor support according to another embodiment described herein. [Figure 4A] FIG. 2 is a perspective view of a susceptor support according to another embodiment described herein. [Figure 4B] FIG. 2 is a perspective view of a susceptor support according to another embodiment described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] For ease of understanding, wherever possible, the same reference numbers have been used to designate identical elements that are common to multiple figures. Furthermore, elements in one embodiment may be advantageously adapted for use in other embodiments described herein.

[0011] The embodiments described herein generally relate to a susceptor support for supporting a susceptor in a deposition process. The susceptor support includes a shaft, a plate having a first major surface coupled to the shaft, and a support element extending from a second major surface of the plate. The plate may be made of a material that is optically transparent to radiant energy from a plurality of energy sources disposed below the plate. The plate may have a thickness that is small enough to minimize radiation transmission losses and large enough to be thermally and mechanically stable to support the susceptor during processing. The thickness of the plate may be in a range of about 2 mm to about 20 mm. The support element may be disposed on the plate or may be integrally formed with the plate. The support element may be provided at one or more locations on the plate outside of a substrate processing diameter. The substrate processing diameter is generally the diameter of the plate that is covered by a substrate disposed on the susceptor during processing.

[0012] 1 is a schematic cross-sectional view of a processing chamber 100, according to one embodiment. The processing chamber 100 may be used for processing one or more substrates, including deposition of material on a deposition surface 116 of the substrate 108. The processing chamber 100 includes, among other components, a plurality of energy sources 102 for heating a backside 104 of a substrate 108 disposed within the processing chamber 100. The plurality of energy sources 102 may be a plurality of heat lamps. The substrate 108 may be supported by a susceptor 105. The susceptor 105 is supported by a susceptor support 150. The susceptor 105 may be made of silicon carbide or graphite with a coating of silicon carbide. The susceptor support 150 includes a shaft 170, a plate 172 coupled to the shaft 170, and a support element 174 extending from the plate 172. The shaft 170 is connected to the center of a first major surface 171 of the plate, and a support element 174 extends from a second major surface 173 of the plate opposite the first major surface 171. The plate 172 is a disk and can be made from a material that is optically transparent to the radiant energy from the multiple energy sources 102 disposed below the plate 172. Optically transparent means that the material transmits most of the radiant energy and very little is reflected and / or absorbed. In one embodiment, the plate is made from quartz, such as fused silica. In other embodiments, the plate 172 is made from alumina, sapphire, or yttria.

[0013] The plate 172 may have a thickness that is small enough to minimize radiation transmission losses and large enough to be thermally and mechanically stable to support the susceptor during processing. The plate thickness may be in the range of about 2 mm to about 20 mm, such as about 4 mm to about 8 mm. The support element 174 may be provided on the plate 172 at one or more locations outside the substrate processing diameter of the plate 172. The substrate processing diameter is generally the diameter of the plate 172 that is covered by the substrate 108 placed on the susceptor 105 during processing. In other words, the support element 174 is not positioned directly under the substrate 108. In one embodiment, the substrate 108 has a diameter of about 300 mm, and the support element 174 is positioned on the plate 172 at a diameter larger than 300 mm, such as about 310 mm to about 360 mm. The plate 172 may have a diameter that is comparable to or larger than the diameter of the susceptor 105. In one embodiment, the plate 172 has a diameter of about 370 mm. In comparison to conventional susceptor supports, the plate 172 provides a uniform medium for the radiant energy to pass through. Furthermore, the support element 174 is not positioned directly below the substrate 108, and therefore the support element 174 does not impede the radiant energy from the multiple energy sources 102 to the backside 104 of the substrate 108. The distance D between the susceptor 105 and the plate 172 may provide more uniform heating of the substrate 108. The distance D may be in the range of about 10 mm to about 60 mm, such as about 30 mm to about 60 mm, and may be, for example, about 40 mm.

[0014] At least a portion of the susceptor support 150 is positioned within the processing chamber 100 between the first enclosure 128 and the second enclosure 114. A substrate 108 may be brought into the processing chamber 100 through the loading port 103 and positioned on the susceptor 105. The susceptor 105 and plate 172, while positioned within the processing position, divide the interior volume of the processing chamber 100 into a processing gas region 156 (between the substrate 108 and the first enclosure 128) and a purge gas region 158 (between the plate 172 and the second enclosure 114). To minimize the effects of spatial specificities of heat and process gas flow within the processing chamber 100 and thus facilitate uniform processing of the substrate 108, the susceptor support 150 may be rotated about its central axis. The susceptor support 150 moves the susceptor 105 axially 134 during loading and unloading, and in some cases while the substrate 108 is being processed.

[0015] Generally, the first enclosure 128 and the second enclosure 114 are formed from an optically transparent material such as quartz. The first enclosure 128 and the second enclosure 114 are thin to minimize thermal memory, typically having a thickness between about 3 mm and about 10 mm, for example about 4 mm. The first enclosure 128 can be thermally controlled by introducing a thermal control fluid, such as a cooling gas, into the thermal control volume 136 through the inlet portal 126 and withdrawing the thermal control fluid through the outlet portal 130. In an embodiment, the cooling fluid circulating through the thermal control volume 136 can reduce deposition on the interior surface of the first enclosure 128. The second enclosure 114 can have a conical shape to withstand the vacuum conditions inside the processing chamber 100. In one embodiment, the second enclosure 114 is made from quartz. Quartz is optically transparent to the radiant energy from the multiple energy sources 102 .

[0016] Optionally, a reflector 122 may be placed on the outside of the first enclosure 128 to reflect radiation emanating from the substrate 108 back to the substrate 108. The reflected radiation improves the efficiency of heating by containing heat that might otherwise escape the processing chamber 100. The reflector 122 may be made of a metal, such as aluminum, brass, or stainless steel.

[0017] The multiple energy sources 102 may be adapted to heat the substrate 108 to a temperature in a range of about 200 degrees Celsius to about 1,400 degrees Celsius, such as about 300 degrees Celsius to about 1,350 degrees Celsius. The multiple energy sources 102 may be positioned in a compartmented housing 145. Each energy source 102 may be disposed inside a tube 143. Multiple thermal radiation sensors 140, which may be pyrometers, may be disposed in the housing 145 to measure the thermal emission of the substrate 108. The sensors 140 are typically disposed at different locations in the housing 145 to facilitate viewing different locations of the substrate 108 during processing. Sensing the thermal emission from different locations of the substrate 108 facilitates comparing the amount of thermal energy (e.g., temperature) at different locations of the substrate 108 to determine whether temperature anomalies or non-uniformities exist. Such non-uniformities may result in non-uniformities in film production, such as thickness and composition. Typically at least two sensors 140 are used, although more than two may be used. Various embodiments may use three, four, five, six, seven, or more sensors 140.

[0018] A thermal sensor 118 may be disposed within the reflector 122 to monitor the thermal condition of the first enclosure 128 or to monitor the thermal condition of the substrate 108 from a perspective opposite that of the sensor 140. Such monitoring may be useful, for example, to determine whether there is an error in the data received from the sensor 140, as compared to the data received from the sensor 140. The thermal sensor 118 may in some cases be an assembly of sensors, the assembly employing more than one individual sensor. Thus, the processing chamber 100 may employ one or more sensors disposed to receive radiation emitted from a first side of the substrate and one or more sensors disposed to receive radiation from a second side of the substrate opposite the first side.

[0019] A controller 160 receives data from the sensors 140 and, based on the data, individually adjusts the power distributed to each energy source 102 or individual groups of energy sources 102. The controller 160 may include power supplies 162 that individually power the various energy sources 102. The controller 160 is set to a particular temperature profile, and based on comparing the data received from the sensors 140, the controller 160 adjusts the power to the energy sources 102 to match the observed thermal data to the particular temperature profile.

[0020] FIG. 2A is a perspective view of a susceptor support 200, according to one embodiment. The susceptor support 200 may be used in the processing chamber 100 of FIG. 1 in place of the susceptor support 150. As shown in FIG. 2A, the susceptor support 200 includes a shaft 170, a plate 172 coupled to the shaft 170, and a number of support elements 203 extending from the plate 172. In one embodiment, the support elements 203 are a number of cylindrical posts that are positioned outside the substrate processing diameter on the plate 172. A number of through holes 201 may be formed in the plate 172 to allow a number of lift pins to pass therethrough. Corresponding through holes may be formed in the susceptor 105 to allow a number of lift pins to pass therethrough.

[0021] The support elements 203 may be made of any suitable material, such as quartz, fused silica, silicon carbide, silicon nitride, graphite coated with silicon carbide, graphite coated with glassy carbon, graphite coated with silicon nitride, glassy carbon, graphite, quartz coated with silicon carbide, or quartz coated with glassy carbon. Each of the support elements 203 may have a height in a range of about 4 mm to about 60 mm, such as about 30 mm to about 60 mm, and a diameter 220 in a range of about 5 mm to about 15 mm, such as about 10 mm. The susceptor 105 (FIG. 1) may be supported directly by the support elements 203 or by pins or caps disposed in or on the support elements 203. In one embodiment, the plate 172 is made of fused silica, the support elements 203 are made of fused silica, and the pins are made of solid silicon carbide.

[0022] The shaft 170 may include a first portion 202, a second portion 204, a spacer 206, and a connector 208. The first portion 202 and the second portion 204 may be made from fused silica, and the spacer 206 may be made from opaque quartz.

[0023] FIG. 2B is a schematic cross-sectional view of the susceptor support 200 of FIG. 2A. As shown in FIG. 2B, the support elements 203 may be coupled to the plate 172. Each support element 203 may include an opening 210 for placing a pin therein. And the susceptor 105 may be supported by the pin disposed in the opening 210. Each support element 203 may include a wall 213 and a portion 212 having a tapered shape. The tapered portion 212 may be connected to the wall 213 and may have a flat upper end surface 222. The portion 212 may engage with a corresponding recess formed on the back side of the susceptor 105 for fixing the susceptor 105. Other suitable methods may be used to fix the susceptor 105 to the support elements 203.

[0024] The tapered shape of the portion 212 may have a straight taper, a segmented taper, or a curved taper. For example, the tapered shape may be a cone. And the tapered portion may form an angle with the wall 213 of the support element 203. The angle may be between about 1° and about 30°, such as about 15°, toward the central axis 215 of the support element 203. As another example, as shown in FIG. 2C, the tapered shape may be a curved portion 224 that is substantially tangent to the wall 213. In that case, the curved portion 224 contacts the wall 213 and curves toward the central axis 215 of the support element 203. Thus, the curved portion 224 may be a rounded end of the support element 203. Or, the curved portion 224 may have the curved taper described above with a flat top surface 222, as shown in FIG. 2C.

[0025] The tapered portion may have a single radius of curvature or may have multiple radii of curvature. In one embodiment, portion 212 has a linear tapered shape that is joined to flat top surface 222 at a curved interface portion 226, as shown in FIG. 2D. Flat top surface 222 may have a diameter 228 that is less than diameter 220 of support element 203, e.g., between about 30% and about 80% of diameter 220 of support element 203. Interface portion 226 may have a radius of curvature that is less than diameter 228 of flat top surface 222, e.g., between about 5% and about 20% of the diameter of the flat top surface. Note that, as mentioned above, curved interface portion 226 may also be used to join curved portion 224 (FIG. 2C) to flat top surface 222. The curved interface section 226 may also be used to join section 212 with a curved top section, using a curved or straight taper, meaning that the top section is not flat.

[0026] Other tapered shapes may be used as well. For example, the tapered shape may include threading in some embodiments to attach an end portion, such as a silicon carbide tip, to the support element 203. In one embodiment, as shown in FIG. 2E, the portion 212 may rise from a step 234 formed in the support element 203. The step 234 may have a side diameter 230 that is 1% to 25%, for example about 5%, of the diameter 220 of the support element 203. The step 234 may include a portion 232 that is substantially perpendicular to the side diameter 230. The portion 232 may then be connected to the top surface 222. Although the side diameter 230 is shown in FIG. 2E as being perpendicular to the wall 213, in other embodiments the side diameter 230 may not be perpendicular to the wall 213. In another embodiment, the entire support element 203 may be conical or frusto-conical. The shape is from where the support element 203 joins the plate 172 to substantially near the end of the support element 203, the end having any desired end features for engaging the susceptor 105. Finally, as discussed above, the taper may be segmented. In one embodiment, the portion 212 may have a frusto-conical first section having a contour that forms a first angle with the wall 213 and a frusto-conical second section having a contour that forms a second angle with the first section, thereby tapering the portion 212 with a linear contour, but forming an angle with the wall 213 that is not constant. For a segmented taper, any number of sections may be used.

[0027] 3A is a perspective view of a susceptor support 300 according to another embodiment described herein. As shown in FIG. 3A, the susceptor support 300 includes a shaft 170, a plate 172 coupled to the shaft 170 at a first major surface 171, and a support element 302 extending from a second major surface 173 of the plate 172. The support element 302 can be a hollow cylinder and have an inner diameter 304 larger than a diameter of the substrate 108 (FIG. 1). In one embodiment, the substrate 108 has a diameter of about 300 mm, and the support element 302 has an inner diameter 304 larger than 300 mm, such as about 310 mm to about 360 mm. The plate 172 can have a diameter similar to or larger than a diameter of the susceptor 105. In one embodiment, the plate 172 has a diameter 306 of about 370 mm. The susceptor 105 can be supported by the support element 302. Alternatively, the substrate 108 may be directly supported by the support element 302. The support element 302 may be welded or bonded to the plate 172, formed integrally with the plate 172, or disposed within a groove formed in the plate 172 to secure the support element 302. The support element 302 may be made from any suitable material, such as quartz, fused silica, silicon carbide, silicon nitride, silicon carbide coated graphite, glassy carbon coated graphite, silicon nitride coated graphite, glassy carbon, graphite, silicon carbide coated quartz, or glassy carbon coated quartz. The support element 302 may have a height within a range of about 30 mm to about 60 mm to have a distance D (FIG. 1) of about 30 mm to about 60 mm.

[0028] The support element 302 may have a thickness 308 in the range of about 2 mm to about 50 mm. The thickness may be constant or may vary with height, orientation, or both. In one embodiment, the radial cross-section of the support element 302 has a square shape, and in another embodiment, the radial cross-section of the support element 302 has a trapezoid shape. The radial cross-section may be constant or may vary with orientation.

[0029] 3B is a perspective view of a susceptor support 320 according to another embodiment described herein. As shown in FIG. 3B, the susceptor support 320 includes a shaft 170, a plate 172 coupled to the shaft 170 at a first major surface 171, and a plurality of support elements 322 extending from a second major surface 173 of the plate 172. Each of the plurality of support elements 322 may have a curvature that follows the curvature of the plate 172. In other words, each support element 322 may have an outer surface 326 that is substantially parallel to a thickness surface 328 of the plate 172. The lengths of the outer surfaces 326 of the plurality of support elements 322 may be the same or different. Adjacent support elements 322 are separated by spaces 324, and the spaces 324 may have the same or different dimensions. The number of support elements 322 may be in the range of 2 to 10, such as 3 to 6.

[0030] The support elements 322 may be made of any suitable material, such as quartz, fused silica, silicon carbide, silicon nitride, silicon carbide coated graphite, glassy carbon coated graphite, silicon nitride coated graphite, glassy carbon, graphite, silicon carbide coated quartz, or glassy carbon coated quartz. Each of the support elements 322 may have a height within a range of about 30 mm to about 60 mm to have a distance D (FIG. 1) of about 30 mm to about 60 mm. The multiple support elements 322 are positioned outside the substrate processing diameter of the plate 172.

[0031] FIG. 4A is a perspective view of a susceptor support 400 according to another embodiment described herein. As shown in FIG. 4A, the susceptor support 400 includes a shaft 170, a plate 172 coupled to the shaft 170 at a first major surface 171, a plurality of support elements 203 extending from a second major surface 173 of the plate 172, and a support element 302 extending from the second major surface 173. The susceptor 105 is supported by the support elements 203, and the support elements 302 are used to block radiant energy coming from the support elements 203. As a result, the radiant energy received by the substrate 108 is from the radiant energy passing through a portion of the plate 172 surrounded by the support elements 302. The support elements 302 may have a diameter larger than the diameter of the substrate 108. And the support elements 203 are disposed outside the support elements 302 on the plate 172. The distance between each support element 203 and support element 302 may be within a range of about 1 mm to about 10 mm. When the susceptor 105 is directly supported by the support elements 203, the height of the support elements 302 may be less than the height of each support element 203. When the susceptor 105 is supported by pins disposed within the support elements 203, the height of the support elements 302 may be greater than the height of each support element 203.

[0032] 4B is a perspective view of a susceptor support 410 according to another embodiment described herein. As shown in FIG. 4B, the susceptor support 410 includes a shaft 170, a plate 172 coupled to the shaft 170 at a first major surface 171, a plurality of support elements 203 extending from a second major surface 173 of the plate 172, and a plurality of support elements 322 extending from the second major surface 173. The susceptor 105 is supported by the support elements 203, and the support elements 322 are used to block radiant energy coming from the support elements 203. As a result, the radiant energy received by the substrate 108 is from radiant energy passing through a portion of the plate 172 surrounded by the support elements 322. The support elements 322 may be positioned adjacent to the support elements 203 to block radiant energy from the support elements 203. In one embodiment, there are three support elements 203 and three support elements 322 positioned adjacent to the support elements 203. The distance between each support element 203 and the corresponding support element 322 can be in the range of about 1 mm to about 10 mm. When the susceptor 105 is directly supported by the support elements 203, the height of each support element 322 can be less than the height of each support element 203. When the susceptor 105 is supported by pins disposed within the support elements 203, the height of each support element 322 can be greater than the height of each support element 203.

[0033] While the forgoing 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, the scope of which is defined by the following claims.

Claims

1. shaft, a plate having a first major surface coupled to the shaft, the plate comprising quartz, fused silica, alumina, sapphire, or yttria, and having a thickness within a range of about 2 mm to about 20 mm; and the apparatus comprising a support element extending from a second major surface of the plate.

2. The apparatus of claim 1 , wherein the plate has a thickness within a range of about 4 mm to about 8 mm.

3. The apparatus of claim 1 , wherein the support element comprises a hollow cylinder.

4. The apparatus of claim 1 , wherein the support element comprises a plurality of cylindrical posts.

5. The apparatus of claim 4 , wherein a cylindrical post of the plurality of cylindrical posts includes a wall and a tapered portion connected to the wall.

6. The device of claim 5 , wherein the tapered portion comprises a linear taper.

7. The device of claim 5 , wherein the tapered portion comprises a curved taper.

8. 5. The apparatus of claim 4, further comprising a hollow cylinder extending from said second major surface of said plate, said plurality of cylindrical posts being positioned outside said hollow cylinder.

9. shaft, a plate having a first major surface coupled to the shaft, the plate comprising quartz, fused silica, alumina, sapphire, or yttria; and an apparatus comprising: a support element extending from a second major surface of the plate, the support element having a height within a range of about 10 mm to about 60 mm.

10. The apparatus of claim 9 , wherein the support element comprises a plurality of cylindrical posts.

11. The apparatus of claim 10 , wherein a cylindrical post of the plurality of cylindrical posts includes a wall and a tapered portion connected to the wall.

12. The device of claim 11 , wherein the tapered portion comprises a linear taper.

13. A processing chamber comprising: A first enclosure member; A second enclosure member; A susceptor support, a plurality of energy sources disposed facing the second enclosure member; At least a portion of the susceptor support is disposed between the first enclosure member and the second enclosure member, and the susceptor support is shaft, a plate having a first major surface coupled to the shaft, the plate comprising quartz, fused silica, alumina, sapphire, or yttria, and having a thickness within a range of about 2 mm to about 20 mm; and A processing chamber comprising a support element extending from a second major surface of the plate.

14. 14. The processing chamber of claim 13, further comprising a susceptor disposed on the susceptor support, wherein a distance between the susceptor and the susceptor support is in a range from about 10 mm to about 60 mm.

15. The processing chamber of claim 13 , wherein the support element comprises a plurality of cylindrical posts.

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