Substrate position calibration on a substrate support of a substrate processing system - Patents.com

Abstract

Provided herein is a method and apparatus for substrate position calibration for a substrate support in a substrate processing system. In some embodiments, a method for positioning a substrate on a substrate support includes obtaining a plurality of backside pressure values ​​corresponding to a plurality of different substrate positions on the substrate support by iteratively placing the substrate at a position on the substrate support, vacuum chucking the substrate to the substrate support to measure a backside pressure, and analyzing the plurality of backside pressure values ​​to determine a calibrated substrate position.

Description

[Technical field]

[0001]

[0001] Embodiments of the present disclosure relate generally to substrate processing systems, and more particularly to positioning a substrate on a substrate support in such processing systems. [Background technology]

[0002] In conventional substrate processing systems, such as microelectronic device manufacturing, fine adjustment of the positioning of the substrate on the substrate support is often required to minimize process non-uniformities caused by inaccurate placement of the substrate on the substrate support. One technique for verifying the position of the substrate is to run the process and analyze a process contour map. Process non-uniformities caused by inaccurate substrate placement can then be addressed to improve the process non-uniformity by modifying the substrate placement based on an analysis of the process contour map. Such substrate placement calibration can be performed at start-up or after a substrate support replacement. However, the inventors have observed that it is difficult to determine the amount of adjustment (e.g., stretch and rotate steps) required for the substrate transfer robot. Also, the inventors have found that the results are dependent on the person performing the calibration, and the required iterations of substrate process, measurement, analysis, and hand-off adjustment of the substrate transfer robot are time-consuming.

[0003]

[0003] Accordingly, the present inventors have provided an improved method and apparatus for calibrating the position of a substrate on a substrate support. Summary of the Invention

[0004]

[0004] Provided herein is a method and apparatus for substrate position calibration for a substrate support in a substrate processing system. In some embodiments, a method of positioning a substrate on a substrate support includes obtaining a plurality of backside pressure values ​​corresponding to a plurality of different substrate positions on the substrate support by iteratively placing the substrate at a position on the substrate support, vacuum chucking the substrate to the substrate support to measure a backside pressure, and analyzing the plurality of backside pressure values ​​to determine a calibrated substrate position.

[0005]

[0005] In some embodiments, an apparatus for calibrating a substrate position on a substrate support having a vacuum chuck includes a calibration substrate including a solid disk having a plurality of through holes arranged through the solid disk along a circle having a diameter proximate to an outer diameter of the solid disk.

[0006]

[0006] In some embodiments, an apparatus for calibrating a substrate position on a substrate support having a vacuum chuck includes a calibration substrate including a solid disk having a diameter of about 150 mm, about 200 mm, about 300 mm, or about 450 mm and a thickness of about 450 micrometers to about 1500 micrometers, the solid disk being made from quartz, silicon, silicon carbide, or aluminum nitride, and a plurality of through holes disposed through the solid disk proximate to an outer diameter of the solid disk.

[0007]

[0007] Further embodiments of the present disclosure are described below.

[0008]

[0008] The embodiments of the present disclosure summarized above and described in more detail below can be understood by reference to the exemplary embodiments of the present disclosure shown in the accompanying drawings. However, the accompanying drawings merely illustrate typical embodiments of the present disclosure and therefore should not be considered as limiting the scope, as the present disclosure may admit of other equally effective embodiments. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a flow diagram of a method for positioning a substrate on a substrate support, according to at least some embodiments of the present disclosure. [Diagram 2] 1 is a schematic top view of a substrate support for use in connection with a method of positioning a substrate on a substrate support, according to at least some embodiments of the present disclosure. [Diagram 3] 1 is a schematic side view of a process chamber for use in connection with a method for positioning a substrate on a substrate support, in accordance with at least some embodiments of the present disclosure. [Figure 4] 1 is a schematic partial side view of a substrate support and a substrate used in connection with a method of positioning a substrate on a substrate support, in accordance with at least some embodiments of the present disclosure. [Diagram 5] 1 is a schematic partial side view of another substrate support and substrate used in connection with a method of positioning a substrate on a substrate support, in accordance with at least some embodiments of the present disclosure. [Figure 6] 1 is a schematic partial side view of another substrate support and substrate used in connection with a method of positioning a substrate on a substrate support, in accordance with at least some embodiments of the present disclosure. [Figure 7] 1 is a schematic top isometric view of a substrate for use in connection with a method for positioning a substrate on a substrate support, according to at least some embodiments of the present disclosure. [Figure 8] 1 is a schematic top isometric view of another substrate for use in connection with a method for positioning a substrate on a substrate support, according to at least some embodiments of the present disclosure. [Figure 9] 1 is a schematic top isometric view of another substrate for use in connection with a method for positioning a substrate on a substrate support, according to at least some embodiments of the present disclosure. [Figure 10] 1 is a graph of backside pressure values ​​versus substrate position in connection with a method of positioning a substrate on a substrate support, in accordance with at least some embodiments of the present disclosure. [Figure 11] 1 is an example graph of backside pressure versus substrate position in connection with a method of positioning a substrate on a substrate support, in accordance with at least some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010]

[0020] To facilitate understanding, the same reference numbers have been used, wherever possible, to designate identical elements common to the drawings. The drawings are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further detail.

[0011]

[0021] Embodiments of a method and apparatus for substrate position calibration for a substrate support in a substrate processing system are provided herein. The method and apparatus of the present invention advantageously facilitates calibration of a substrate position on a substrate support without performing any process on the substrate. The present technique also advantageously eliminates the requirement for analysis of process results and contour maps of the process. The present technique is also more repeatable, thus advantageously reducing or eliminating variability in results that is dependent on the operator performing the calibration.

[0012]

[0022] FIG. 1 is a flow diagram of a method 100 for positioning a substrate on a substrate support according to at least some embodiments of the present disclosure. FIGS. 2-9 depict various embodiments of processing equipment used in connection with method 100, which are described in more detail below. Method 100 may be performed any time a substrate is placed on a substrate support for processing. In some embodiments, method 100 may be performed at the start of a substrate run, after maintenance, repair, or installation of a substrate support, after maintenance, repair, or installation of a substrate transfer robot that places the substrate on the substrate support, after bringing a processing chamber online after a shutdown, after changing the process temperature of a process being run, or any time the position of the substrate on the substrate support is deemed inaccurate.

[0013]

[0023] For example, Figure 2 is a schematic top view of a substrate support suitable for use in connection with method 100 in accordance with at least some embodiments of the present disclosure. The configuration and arrangement of components of the substrate support shown in Figure 2 is merely exemplary and is not meant to be limiting. As shown in Figure 2, the substrate support 200 is a vacuum chuck having a body 202 that includes a vacuum region 204 defined between support structures of the substrate support 200.

[0014]

[0024] For example, an outer seal band (seal ring) 206 having an outer diameter larger than the outer diameter of a supported substrate and an inner diameter smaller than the inner diameter of a supported substrate is provided so that a vacuum can be maintained within the vacuum region when the substrate is properly positioned on the seal ring 206. In some embodiments, a plurality of support pins 210 can be disposed on a support surface within the vacuum region 204. A plurality of lift pin openings 212 can also be provided to facilitate selective raising and lowering of the substrate by the lift pins on the substrate support 200. In embodiments in which the lift pins do not form a seal with the substrate support, a corresponding lift pin seal ring 214 can be provided to limit or prevent leakage from the lift pin openings 212 into the vacuum region 204. The seal ring 206, support pins 210, and upper surfaces of the lift pin seal ring 214 collectively form a support surface for the substrate when positioned on the substrate support. At least one opening 208 is provided to couple the vacuum region 204 to a vacuum source (e.g., pump 310 shown in FIG. 3).

[0015]

[0025] FIG. 3 is a schematic side view of a process chamber suitable for use in connection with the method 100 according to at least some embodiments of the present disclosure. The configuration and arrangement of the process chamber components shown in FIG. 3 are merely illustrative and are not meant to be limiting. Additionally, conventional components or other details not necessary for an understanding of the present disclosure are omitted from the figures so as not to obscure the present disclosure. As shown in FIG. 3, the process chamber 304 includes a substrate support, such as the substrate support 200 described above, in an interior region 332 of the process chamber 304. As described above, the substrate support 200 is a vacuum chuck and is coupled to a vacuum source, such as a pump 310 or other suitable vacuum source. A pressure sensor, such as a pressure gauge 330, is operably coupled to the vacuum region 204 to measure the backside pressure of the vacuum region 204. In some embodiments, the substrate support 200 may further include a heater, such as a resistive heater 312 coupled to a heater power supply 314. A substrate 302 is shown disposed on a seal ring 206 of the substrate support 200.

[0016]

[0026] The process chamber 304 includes an opening, such as a slit valve 306, that selectively opens the process chamber 304 to facilitate movement of a substrate into and out of an interior region 332 of the process chamber 304, for example, via a substrate transfer robot 308. Control of the substrate transfer robot 308 facilitates control of the position of the substrate 302 above the substrate support 200, and thus on the substrate support 200, as it is transferred from the substrate transfer robot 308 to the substrate support 200. A number of lift pins 328 may be provided to aid in the transfer of the substrate 302 between the substrate transfer robot 308 and the substrate support 200.

[0017]

[0027] The process chamber 304 is configured to perform one or more of a variety of processes, such as a deposition process. A gas source 316 is coupled to an interior region 332 of the process chamber 304 to supply process gases necessary for substrate processing (e.g., deposition). In addition, the gas source 316 supplies at least one inert gas, such as nitrogen gas or a noble gas (e.g., argon). A pump 326 is coupled to an interior region 332 of the process chamber 304 to maintain a desired pressure within the process chamber and to remove process gases and processing by-products during processing.

[0018]

[0028] In some embodiments, a controller 318 is coupled to components of the process chamber 304, including pressure gauge 330, substrate transfer robot 308, etc., to facilitate control of the process chamber 304. The controller 318 may be any form of general-purpose computer processor that can be used in an industrial environment to control various chambers and sub-processors. The controller includes a central processing unit (CPU) 320, a memory 322, and support circuits 324. The memory, or computer readable medium 322, of the CPU 320 may be one or more of readily available memories such as random access memory (RAM), read only memory (ROM), a floppy disk, a hard disk, or any other form of digital storage, local or remote. The support circuits 324 are coupled to the CPU 320 to support the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input / output circuits and subsystems, etc. The one or more methods and / or processes may generally be stored in memory 322 as software routines that, when executed by CPU 320, cause the process chamber 304 to perform processes, such as the substrate positioning methods and other processes (such as deposition processes) disclosed herein. For example, the methods 100 described herein may be executed automatically under control of controller 318, and a calibrated hand-off position of the substrate transfer robot may be stored for repeated use in transferring substrates until recalibration is desired.

[0019]

[0029] The method 100 generally begins at 102 where multiple backside pressure values ​​are obtained at a corresponding number of different substrate positions on the substrate support. Each backside pressure value is obtained by placing the substrate at a position on the substrate support as shown at 110, vacuum chucking the substrate to the substrate support as shown at 112, and measuring the backside pressure as shown at 114. To facilitate vacuum chucking, the pressure in the interior region 332 of the process chamber is maintained at a pressure higher than the pressure in the vacuum region 204, such as at least about 1 Torr higher than the pressure in the vacuum region 204. For example, in some embodiments, while vacuum chucking the substrate, the pressure in the process chamber including the substrate support (and substrate) is maintained at about 5 Torr (although other pressures may be used). In some embodiments, the pressure is maintained while flowing an inert gas, such as nitrogen gas or a noble gas (e.g., argon, etc.), into the process chamber. In some embodiments, the pressure in the process chamber is optionally increased to a predetermined pressure before measuring the backside pressure as shown at 113. In some embodiments, the predetermined pressure is about 20 to about 40 Torr (although other pressures may be used). In some embodiments, the substrate support may be heated to a first temperature during the placement of the substrate, vacuum chucking the substrate, and measuring the backside pressure value. In some embodiments, the first temperature is the temperature at which a subsequent process (e.g., a deposition process, etc.) is performed.

[0020]

[0030] The placement and chucking of the substrate on the substrate support and the corresponding backside pressure measurements are repeated at different substrate positions, which are obtained by controlling parameters of a substrate transfer robot (e.g., substrate transfer robot 308) that places the substrate on the substrate support. The multiple substrate positions are obtained by adjusting a hand-off position of the substrate transfer robot that moves the substrate into the process chamber and positions the substrate above the substrate support. For example, by controlling the extension and / or rotation of the substrate transfer robot (or other parameters that affect the position of the substrate relative to the substrate support), various positions of the substrate on the substrate support can be obtained and the corresponding backside pressures can be measured.

[0021]

[0031] After acquiring the multiple backside pressure values, the multiple backside pressure values ​​are analyzed to determine a calibrated substrate position, as shown at 104. For example, FIGS. 10 and 11 are graphs of backside pressure values ​​acquired and used in connection with a method of positioning a substrate on a substrate support according to at least some embodiments of the present disclosure. As shown in FIGS. 10 and 11, the measured backside pressure varies depending on the handoff offset (or position) of the substrate transfer robot. The position of the substrate transfer robot determines the position of the substrate positioned on the substrate support, and therefore the position of the substrate on the substrate support when the transfer is completed. FIGS. 10-11 show exemplary data based on a lateral handoff offset. However, the handoff offset (or position) of the substrate transfer robot can be varied two-dimensionally along a substrate transfer plane parallel to the substrate support surface to obtain more accurate substrate positioning data. The control of the substrate transfer robot can be along xy coordinates in the substrate transfer plane using extension and rotation coordinates in the substrate transfer plane, or any other suitable parameters of substrate handoff position control.

[0022]

[0032] When a substrate is positioned on the substrate support and vacuum pressure is applied to hold the substrate, the backside pressure increases with increasing leakage (e.g., increasing leak rate) from the interior region of the process chamber into the vacuum region of the substrate support. In some embodiments, the calibration substrate may be a standard size substrate (e.g., a substrate having dimensions comparable to those of a standard semiconductor wafer size, e.g., about 450 mm, about 300 mm, about 200 mm, about 150 mm, etc., that the substrate support is designed to support). The calibration substrate has a thickness similar to that of a standard semiconductor wafer (e.g., about 450 μm to about 1500 μm) because it is intended to be handled by the same equipment as the production substrates. The calibration substrate may be made of any process-compatible material, such as quartz, silicon, silicon carbide, aluminum nitride, etc.

[0023]

[0033] In some embodiments, the calibration substrate is solid (e.g., has no through holes or perforations formed therein). In such embodiments, the calibration substrate may be a production substrate (e.g., a silicon or semiconductor substrate on which subsequent processes are performed in the same process chamber). In some embodiments, the calibration substrate may be a non-production substrate. In some embodiments, the calibration substrate may be a blank substrate. The blank substrate may be formed of a homogenous material and may be uncoated or uniformly coated.

[0024]

[0034] For example, FIG. 4 is a schematic partial side view of a substrate support and a substrate used in connection with a method of positioning a substrate on a substrate support according to at least some embodiments of the present disclosure. The substrate support shown in FIG. 4 may be as described with respect to FIGS. 2-3 above. As shown in FIG. 4, when a substrate 402 (which is a solid substrate) is positioned on the substrate support, the backside of the substrate is disposed on the seal ring 206. When the substrate 402 is perfectly positioned on the substrate support, the center of the substrate is aligned with the center of the seal ring 206 (e.g., they are concentric), and the edge of the substrate and the outer diameter of the seal ring are equidistantly spaced around the entire circumference of the substrate. However, if the substrate 402 is incorrectly positioned on the substrate support, the edge of the substrate may be miscentered with respect to the seal ring 206, with one edge disposed on a small portion of the seal ring 206, or may be completely off the seal ring 206. Such misalignment may cause various leaks from the interior region of the process chamber into the vacuum region 204 (the amount of leaks depends on the amount of misalignment).

[0025]

[0035] Additionally, other components within the process chamber, such as an edge ring 404, may be positioned around the substrate support to limit the amount of possible misalignment of the substrate 402 on the substrate support. In some embodiments, the width 408 of the seal ring is small enough and the distance 406 between the outer edge of the substrate and an adjacent process chamber component (e.g., the edge ring 404) is large enough to allow sufficient room for substrate misalignment to result in a leak large enough to have a measurable effect on the backside pressure.

[0026]

[0036] For example, FIG. 10 is a graph 1000 illustrating a plot 1006 of substrate transfer robot handoff offset (axis 1002) versus backside pressure (axis 1004). As can be seen from the graph, plot 1006 indicates that the center position of the substrate transfer robot handoff corresponds to the lowest backside pressure measurement. As the substrate transfer robot offset increases in either direction, there is greater leakage, resulting in higher backside pressure measurements. When the substrate transfer robot handoff offset becomes large enough, the edge of the substrate will slip off the seal ring and the backside pressure will rise rapidly, as can be seen from the nearly vertical portion of plot 1006. Thus, in some embodiments, multiple backside pressure values ​​can be analyzed to determine a substrate position having an associated backside pressure value that is the minimum of the multiple backside pressure values ​​or is within a predetermined tolerance of the minimum of the multiple backside pressure values.

[0027]

[0037] In some embodiments, the size of the gap between the edge of the substrate and the edge ring is sufficiently small and the width of the seal ring is sufficiently large that the lateral range of motion of the substrate is limited such that no substantial leakage occurs between the substrate and the seal ring, regardless of the position of the substrate on the substrate support.

[0028]

[0038] For example, FIG. 5 is a schematic partial side view of a substrate support and substrate used in connection with a method of positioning a substrate on a substrate support according to at least some embodiments of the present disclosure. The substrate support shown in FIG. 5 may be as described with respect to FIGS. 2-3 above. As shown in FIG. 5, when a substrate 502 is positioned on the substrate support, the backside of the substrate is disposed on the seal ring 206. When the substrate 502 is fully positioned on the substrate support, the center of the substrate is aligned with the center of the seal ring 206 (e.g., they are concentric), and the edge of the substrate and the outer diameter of the seal ring are equidistantly spaced around the entire circumference of the substrate. However, in embodiments consistent with FIG. 5, the width 508 of the seal ring is large enough relative to the distance 506 between the outer edge of the substrate and an adjacent process chamber component (e.g., edge ring 404) that leakage into the vacuum region 204 due to misalignment of the solid substrate may not occur sufficiently for proper position determination based on backside pressure measurements, or the leakage may be so small that determination is more difficult and imprecise.

[0029]

[0039] Thus, in some embodiments, the substrate 502 may include a plurality of through holes 510 disposed through a portion of the substrate corresponding to the location of a seal ring. As used herein, corresponding to the location of a seal ring means that the through holes are disposed above the seal ring when the substrate is centered above the substrate support. Each of the through holes 510 may have a diameter selected to allow sufficient leakage to facilitate the measurements described herein. In some embodiments, the through holes 510 may have a diameter of about 0.02 inches (about 0.5 mm) to about 0.07 inches (about 1.8 mm), or about 0.03 inches (about 0.75 mm) to about 0.04 inches (about 1 mm). In some embodiments, the through holes 510 are positioned along a circle having a diameter close to but larger than the inner diameter of the seal ring (as shown in FIG. 5). The through holes 510 are positioned such that when the substrate 502 is positioned off-center on the substrate support, the distance 512 between the center of the through hole and the edge of the seal ring (e.g., the edge of the inner diameter shown in FIG. 5) is selected to allow leakage from the interior region of the process chamber through the through holes 510 into the vacuum region 204. For example, in some embodiments, on a 12 inch (300 mm) substrate, the through holes 510 may be centered on a circle having a diameter of about 10.939 inches (about 277.85 mm) to about 11.515 inches (292.48 mm), e.g., about 10.95 inches (about 278.13 mm). The hole locations may be sized for other sized substrates.

[0030]

[0040] Thus, if the substrate 502 is misaligned on the substrate support, one or more of the through-holes 510 will be positioned close to the inner edge of the seal ring 206 or will be positioned beyond the edge of the seal ring 206 and above the vacuum region 204. Such misalignment will result in varying leakage from the interior region of the process chamber into the vacuum region 204 (the amount of leakage will depend on the amount of misalignment). Analysis of such variations in backside pressure measurements based on substrate position can yield a graph similar to plot 1006 shown in FIG. 10, where the backside pressure measurements increase as the offset increases.

[0031]

[0041] Alternatively, in some embodiments, the positions of the through holes are reversed such that when the substrate is centered on the substrate support, the through holes are positioned above the vacuum regions, but when the substrate is misplaced on the substrate support, at least one of the through holes is covered. For example, in some embodiments, the substrate 602 may include a plurality of through holes 610 positioned through a portion of the substrate that corresponds to the vacuum regions 204 and is proximate to the location of the seal ring 206. As used herein, "corresponding to the location of the vacuum region" means that the through holes are positioned above the vacuum regions when the substrate is centered on the substrate support. As used herein, "proximate to the location of the seal ring" means that the through holes are positioned sufficiently proximate to the seal ring such that one or more of the through holes may be positioned above the seal ring when the substrate is off-centered on the substrate support.

[0032]

[0042] In some embodiments, the through-holes 610 are positioned along a circle having a diameter that is close to but smaller than the inner diameter of the seal ring (as shown in FIG. 6). The through-holes 610 are positioned such that when the substrate 602 is centered on the substrate support, the diameter 614 of the through-holes is located entirely or mostly above the vacuum region and close to the edge of the seal ring (e.g., the diametrically inner edge as shown in FIG. 6). The through-holes 610 are further positioned such that when the substrate 602 is positioned off-center on the substrate support, one or more of the through-holes 610 may move over the edge of the seal ring (e.g., the diametrically inner edge as shown in FIG. 6) to reduce leakage from the interior region of the process chamber through the through-holes 610 into the vacuum region 204.

[0033]

[0043] Thus, when the substrate 602 is misaligned on the substrate support, one or more of the through-holes 610 will be positioned partially or completely over the seal ring 206, partially or completely blocking leakage from the interior region of the process chamber into the vacuum region 204 through the through-holes 610. Different amounts of misalignment will result in varying amounts of blocking of leakage from the interior region of the process chamber into the vacuum region 204 (the amount of leakage being dependent on the amount of misalignment). Analysis of such variations in backside pressure measurements based on substrate position can yield a graph similar to plot 1106 shown in FIG. 11, where increasing offsets decrease the backside pressure measurements.

[0034]

[0044] Specifically, FIG. 11 is an exemplary graph 1100 illustrating an exemplary plot 1106 of substrate transfer robot handoff offset (axis 1102) versus backside pressure (axis 1104). Plot 1106 shows that the center position of the substrate transfer robot handoff corresponds to the highest backside pressure measurement. Increasing the substrate transfer robot offset in either direction reduces leakage, resulting in a lower backside pressure measurement. If the substrate transfer robot handoff offset is large enough, the substrate opening moves onto the seal ring, causing a rapid drop in backside pressure, as can be seen from the nearly vertical portion of plot 1106. Thus, a calibrated substrate position can be found by analyzing multiple backside pressure values ​​to determine a substrate position having an associated backside pressure value that is the maximum of the multiple backside pressure values ​​or is within a predetermined tolerance of the maximum of the multiple backside pressure values.

[0035]

[0045] In embodiments in which the calibration substrate has through holes, similar to those shown in Figures 5 and 6, the holes can be arranged in many different ways. The location, number, and diameter of the holes can be selected to obtain the desired accuracy of the substrate position. For example, Figure 7 shows a substrate 700 including a solid disk 702 and multiple sets of through holes 706. The substrate can also include a notch 704 or other positioning feature to facilitate orientation of the substrate. Although three sets of three through holes are shown, there may be more or fewer sets of through holes, and each set may have more or fewer holes than three. The through holes may be equidistantly spaced within each set of through holes, and multiple sets of through holes may be equidistantly spaced. Providing the through holes in sets advantageously allows for a larger open area without using large diameter holes that may be positioned too close to the edge of the substrate. The larger open area allows for a larger difference between the leaking and sealing positions of the substrate, which advantageously improves the ease of calculating the center position. FIG. 8 illustrates a substrate 800 including a solid disk 802 and an exemplary number of through-holes 806. FIG. 18 illustrates sixteen equally spaced through-holes. The substrate 800 also illustrates a positioning notch 804. Providing a larger number of holes advantageously improves the positioning accuracy of the calibration substrate. FIG. 9 illustrates a substrate 900 including a solid disk 902 and an exemplary number of through-holes 906. FIG. 9 illustrates four equally spaced holes. Providing fewer through-holes advantageously simplifies and reduces the cost of manufacturing the calibration substrate. The substrate 900 also illustrates a positioning notch 904.

[0036]

[0046] 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.

Claims

1. 1. A method for positioning a substrate on a substrate support, comprising the steps of: obtaining a plurality of backside pressure values ​​corresponding to a plurality of different substrate positions on a substrate support; placing a substrate at a location on the substrate support; vacuum chucking the substrate to the substrate support and measuring backside pressure; analyzing the plurality of backside pressure values ​​to determine a calibrated substrate position. by repeatedly performing the above steps to obtain a plurality of backside pressure values ​​corresponding to a plurality of different substrate positions on the substrate support. The method includes:

2. maintaining a pressure within a process chamber containing the substrate support greater than the backside pressure; The method of claim 1 further comprising:

3. The method of claim 2 , wherein maintaining a pressure in the process chamber further comprises flowing an inert gas into the process chamber.

4. 2. The method of claim 1 , wherein the plurality of different substrate positions are obtained by adjusting a hand-off position of a substrate transfer robot that moves the substrate into a process chamber containing the substrate support and positions the substrate over the substrate support.

5. 2. The method of claim 1, wherein analyzing the plurality of backside pressure values ​​to determine the calibration substrate position comprises determining a substrate position having an associated backside pressure value that is a minimum of the plurality of backside pressure values ​​or that is within a predetermined tolerance of the minimum of the plurality of backside pressure values.

6. 6. The method of claim 5, wherein the substrate support includes a seal ring supporting an outer edge of the substrate, the substrate being a solid substrate, and positioning the substrate such that the outer edge of the substrate is disposed radially inward of the seal ring increases the leakage rate into a region between the substrate support and a backside of the substrate.

7. 6. The method of claim 5, wherein the substrate support includes a seal ring supporting an outer edge of the substrate, the substrate including a plurality of holes positioned proximate an outer diameter of the substrate that are in alignment with the seal ring when the substrate is centered on the substrate support, and positioning the substrate such that any of the plurality of holes are positioned radially inward of the seal ring increases the rate of leakage into the region between the substrate support and the backside of the substrate.

8. 2. The method of claim 1, wherein analyzing the plurality of backside pressure values ​​to determine the calibration substrate position comprises determining a substrate position having an associated backside pressure value that is a maximum of the plurality of backside pressure values ​​or that is within a predetermined tolerance of a maximum of the plurality of backside pressure values.

9. 10. The method of claim 8, wherein the substrate support includes a seal ring supporting an outer edge of the substrate, the substrate includes a plurality of holes disposed proximate an outer diameter of the substrate at a location disposed radially inward of the seal ring proximate the seal ring when the substrate is centered on the substrate support, and positioning the substrate such that any of the plurality of holes are disposed over the seal ring reduces a leak rate into a region between the substrate support and a backside of the substrate.

10. The method of claim 1 , further comprising maintaining the substrate support at a temperature for a subsequent process while acquiring a plurality of backside pressure values.

11. 10. The method of claim 1, further comprising increasing the pressure in a process chamber containing the substrate support to a predetermined pressure before measuring the backside pressure.

12. The method of claim 11 , wherein the predetermined pressure is from about 20 to about 40 Torr.

13. 10. The method of claim 1, further comprising, when a desired calibration substrate position is obtained, storing said calibration substrate position until recalibration is desired.

14. 10. The method of claim 1, wherein the substrate is a calibration substrate having dimensions comparable to a substrate that the substrate support is designed to support.

15. 10. A non-transitory computer readable medium storing computer instructions that, when executed by at least one processor, cause the at least one processor to perform the method of any one of claims 1 to 9.

16. 20. The non-transitory computer readable medium of claim 15, further comprising maintaining the substrate support at a subsequent process temperature while acquiring a plurality of backside pressure values.

17. 20. The non-transitory computer readable medium of claim 15, further comprising increasing a pressure in a process chamber containing the substrate support to a predetermined pressure prior to measuring backside pressure.

18. 20. The non-transitory computer readable medium of claim 17, wherein the predetermined pressure is from about 20 to about 40 Torr.

19. The non-transitory computer readable medium of claim 15 , further comprising, when a desired calibration substrate position is obtained, storing the calibration substrate position until recalibration is desired.

20. 20. The non-transitory computer readable medium of claim 15, wherein the substrate is a calibration substrate having dimensions comparable to a substrate that the substrate support is designed to support.

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