Wafer lift pin mechanism for preventing local backside deposition

Abstract

An apparatus includes a lifting pin for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber. The lifting pin includes a tapered top end that tapers downwards and a columnar bottom end. The apparatus includes a lifting pin bracket for supporting the bottom end of the lifting pin.

Description

Technical Field

[0001] This disclosure relates generally to a substrate processing system, and more specifically to a lifting pin mechanism for preventing localized backside deposition on a semiconductor wafer. Prior Technology

[0002] The background description provided herein is for the purpose of generally presenting the context of this disclosure. The work of the inventors currently listed, to the extent described in this Prior Art section, and in any respect that may not otherwise be considered Prior Art at the time of filing, is neither explicitly nor implicitly considered Prior Art detrimental to this disclosure.

[0003] Substrate processing systems are used to deposit, etch, ashing, clean, or otherwise process films on substrates (e.g., semiconductor wafers). A substrate processing system typically includes a processing chamber, a gas distribution device, and a substrate support assembly. During processing, the substrate is arranged on the substrate support assembly. Different gas mixtures can be introduced into the processing chamber. Radio frequency (RF) plasma and / or heat can be used to activate chemical reactions.

[0004] Lifting pins are used to allow the transport and removal of substrates from a processing chamber using a robotic arm. Typically, the upper end of the lifting pin is flush with or below the upper surface of the substrate support assembly. The bottom of the lifting pin is located in and held in place by a lifting pin holder. During substrate transport or removal, the lifting pin rises relative to the upper surface of the substrate support assembly to elevate the substrate and provide a gap between the substrate and the substrate support assembly. This gap between the substrate and the substrate support assembly allows for the insertion or removal of the end effector of the robotic arm. Summary of the Invention

[0005] An apparatus includes a lifting pin for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber. The lifting pin includes a tapered top end that tapers downwards and a columnar bottom end. The apparatus includes a lifting pin support for supporting the bottom end of the lifting pin.

[0006] Among other features, the device further includes a top plate of a substrate support assembly having a tapered aperture that tapers downwards. When the lifting pin is in the lowered position, the tip of the lifting pin hangs from the tapered aperture. The device further includes an annular structure disposed at the base of the substrate support assembly to support the lifting pin bracket and to raise and lower the semiconductor substrate relative to the top plate. When the lifting pin is in the lowered position, the lifting pin bracket is suspended above the annular structure.

[0007] Among other features, the device further includes a pad disposed in a slot within the annular structure. When the annular structure raises the lifting pin to lift the semiconductor substrate from the top plate, the lifting pin support rests on the pad. The device further includes a retainer disposed on the pad surrounding the lifting pin support when the lifting pin rests on the pad.

[0008] In another feature, the substrate support assembly includes a top plate with a tapered hole that tapers downwards. When the lifting pin is in the lowered position, the tapered hole supports the top of the lifting pin, which then hangs from the tapered hole.

[0009] In another feature, when in the lowered position, the top of the lifting pin is suspended from the conical hole at a predetermined distance from the top surface of the top plate of the substrate support assembly.

[0010] In another feature, the device further includes an annular structure disposed at the base of the substrate support assembly to support the lifting pin bracket and raise and lower the semiconductor substrate relative to the substrate support assembly.

[0011] In another feature, when in the lowered position, the top of the lifting pin is suspended from a conical hole in the top plate of the base plate support assembly, and the conical hole in the top plate tapers downward; and the lifting pin bracket supporting the bottom of the lifting pin is suspended above the annular structure.

[0012] In another feature, the device further includes a pad disposed in a slot of the annular structure. When the annular structure raises the lifting pin to lift the semiconductor substrate from the top plate, the lifting pin support rests on the pad.

[0013] In another feature, the device also includes an annular retainer arranged on the gasket.

[0014] In another feature, when the lifting pin bracket rests on the pad, the annular retainer surrounds the base of the lifting pin bracket.

[0015] Among other features, the lift pin further includes a groove near its bottom. The lift pin bracket includes a ball lock to engage with the groove.

[0016] In another feature, the lifting pin, lifting pin bracket, gasket, and retainer are made of ceramic material.

[0017] Among other features, a system includes a plurality of lifting pins for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber. Each lifting pin includes a tapered apex with a downward taper and a columnar base. The system further includes a plurality of lifting pin supports. Each lifting pin support is used to support the base of a corresponding lifting pin. The system further includes a top plate of the substrate support assembly, the top plate including a plurality of tapered holes with a downward taper. When the lifting pins are in the lowered position, the apex of the lifting pin is suspended from the tapered hole. The system further includes an annular structure disposed at the base of the substrate support assembly to support the lifting pin supports and raise and lower the semiconductor substrate relative to the top plate. When the lifting pins are in the lowered position, the lifting pin supports are suspended above the annular structure.

[0018] In another feature, the system further includes a plurality of pads, each disposed in a plurality of slots within the annular structure. When the annular structure raises the lifting pins to lift the semiconductor substrate from the top plate, the lifting pin supports rest on the corresponding pads. The raised semiconductor substrate is parallel to the top plate.

[0019] In another feature, the system further includes a plurality of retainers disposed on each of a plurality of gaskets. When the lifting pin bracket rests on the gasket, the retainers surround each of the plurality of lifting pin brackets.

[0020] Among other features, the lifting pin includes a first conical portion, a second portion extending from the first conical portion, and a third columnar portion including a groove. The third columnar portion extends from the second portion and is inserted into a bracket that includes a ball lock to lock into the groove.

[0021] Among other features, the lift pin assembly includes a lift pin for raising and lowering the semiconductor substrate relative to the substrate support assembly within the processing chamber, and a lift pin holder for supporting the bottom end of the lift pin. The lift pin has a downwardly tapered top and a columnar bottom. The lift pin system includes a groove near the bottom end. The lift pin holder system includes a ball lock for locking into the groove.

[0022] Among other features, a system includes a lifting pin assembly and a substrate support assembly. The substrate support assembly includes a top plate having a downwardly tapered hole. When the lifting pin is in the lowered position, the lifting pin is suspended from the top surface of the top plate at a predetermined distance from the tapered hole, with the top end of the lifting pin supported by the tapered hole.

[0023] Among other features, the system includes a top plate for a lifting pin assembly and a substrate support assembly. The top plate of the substrate support assembly includes a tapered hole that tapers downwards. When the lifting pin is in the lowered position, the tip of the lifting pin hangs from the tapered hole. The system further includes an annular structure disposed at the base of the substrate support assembly to support the lifting pin support and to raise and lower the semiconductor substrate relative to the top plate. When the lifting pin is in the lowered position, the lifting pin support is suspended above the annular structure.

[0024] Among other features, the system further includes a gasket and a retainer. The gasket is disposed in a slot of the annular structure. When the annular structure raises the lifting pin to lift the semiconductor substrate from the top plate, the lifting pin support rests on the gasket. When the lifting pin rests on the gasket, the retainer is disposed on the gasket surrounding the lifting pin support.

[0025] Further applications of this disclosure will become apparent from the detailed description, the scope of the claims, and the accompanying drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Simple Explanation of the Diagram

[0026] A more comprehensive understanding of this disclosure will be gained through detailed descriptions and accompanying drawings, in which:

[0027] Figures 1A and 1B show examples of substrate processing systems;

[0028] Figure 2 shows an example of a substrate support assembly used in the substrate processing system of Figures 1A and 1B;

[0029] Figure 3 shows a first example of a lifting pin used with the substrate support assembly of Figure 2;

[0030] Figure 4 shows a second example of a lifting pin used with the substrate support assembly of Figure 2;

[0031] Figure 5 shows a second example of a lifting pin in more detail;

[0032] Figure 6 shows the second lifting pin in the raised position;

[0033] Figure 7 shows the second lifting pin in the lowered position;

[0034] Figure 8 shows a cross-sectional view of the second lifting pin, the lifting pin bracket assembly, the gasket, and the gasket retainer;

[0035] Figure 9 shows the gasket retainer in more detail;

[0036] Figures 10A and 10B show a ball-lock type lifting pin bracket assembly used with the substrate support assembly of Figure 2;

[0037] Figures 11A and 11B show a fork-lock type lifting pin bracket assembly used with the substrate support assembly of Figure 2; and

[0038] Figure 12 schematically shows a slotted lifting ring used in conjunction with the substrate support assembly of Figure 2.

[0039] In the illustration, the illustration labels can be reused to identify similar and / or identical elements. Implementation

[0040] This disclosure provides a novel design for a wafer lift pin that prevents wafer backside deposition near the lift pin hole location in the ESC pedestal. The lift pin design prevents localized flow of process gas to the wafer backside and also prevents deposition on the wafer backside by reducing the gap variation between the lift pin and the wafer.

[0041] Typically, a lift pin passes through a circular hole or aperture in the stage, where it contacts and lifts the wafer. There is a gap between the hole through which the lift pin passes and the lift pin itself. The lift pin is cylindrical and allows process gases to reach the back side of the wafer. Furthermore, when the lift pin is in the lowered position, its height is relative to a movable ring a few inches away. Therefore, the height of the lift pin relative to the wafer depends on many factors, such as the height of the movable ring and the thermal expansion of the lift pin and stage assembly.

[0042] The lift-pin design disclosed herein solves the back-side deposition problem by enclosing the process gas flow to the back side of the wafer and by increasing the repeatability of the lift-pin height relative to the pedestal and wafer. Specifically, the lift-pin has a tapered tip that engages with a matching tapered feature in the lift-pin bore of the pedestal. This engaging cone seals the lift-pin bore of the process gas flow. When the lift-pin is in the lowered position, the lift-pin height is set using this tapered pedestal bore, which also defines the height of the lift-pin relative to the pedestal surface. Specifically, during the lowered position, the tapered tip of the lift-pin hangs down from the tapered pedestal bore, and the lift-pin does not contact the lift ring that would move the lift-pin to the upper position. This eliminates variations in lift-pin height caused by factors such as actuator position, manufacturing tolerances of individual components, and thermal expansion.

[0043] By attaching a ceramic weight assembly (e.g., a ceramic lift pin holder) to the bottom of the lift pin, the lift pin of this disclosure is forced down onto the pedestal. This weight assembly is made entirely of ceramic material to prevent corrosion and thus prevent wafer placement and defect problems. This ceramic weight assembly can be easily removed from the bottom of the lift pin with one hand. This maintains the ability to remove the lift pin from the top of the pedestal for easy disassembly and maintenance. For example, the ceramic weight assembly may comprise a ball-lock type or fork-lock type lift pin holder made of ceramic material.

[0044] For example, the lift pins disclosed herein are made of sapphire. The tapered tips of the lift pins have complex mechanical functions precisely setting the drop height of the lift pin. The rise height of the lift pins is determined by the lift ring. The rise height of each lift pin is further adjusted by thin sapphire shims. Each shim is secured by a metal or ceramic ring, which acts as a weight to prevent the shim from falling out of the mating hole in the lift ring. Ceramic rings can be thinner than metal rings and do not corrode, thus preventing contamination problems. Using the tapered tips of the lift pins to seal the lift pin holes prevents process gases from flowing to the wafer back side. Directly positioning the lift pins relative to the pedestal allows for more repeatable lift pin positions during deposition and all other wafer processing. These and other features of the lift pin design are explained in detail below.

[0045] This disclosure is organized as follows. First, examples of a substrate processing system are shown and described with reference to Figures 1A and 1B. An example of a substrate support assembly including a lifting pin and a lifting pin bracket assembly is shown and described with reference to Figure 2. Examples of lifting pin designs and lifting pin bracket assemblies are shown and described with reference to Figures 3-9. A ball-lock type lifting pin bracket assembly is shown and described with reference to Figures 10A and 10B. A fork-lock type lifting pin bracket assembly is shown and described with reference to Figures 11A and 11B. An annular platform (i.e., a lifting ring) having a slot in which a shim can be installed is shown and described with reference to Figure 12. Although only two examples of substrate processing systems are shown, the lifting pin designs described herein can be used with any other type of substrate processing system.

[0046] Figure 1A shows a substrate processing system 10 including a processing chamber 12, which surrounds other components of the substrate processing system 10 and contains RF plasma (if used). The substrate processing system 10 includes a spray head 14 and a substrate support assembly 16. A substrate 18 is disposed on the substrate support assembly 16. The spray head 14 introduces and dispenses processing gases during the processing of the substrate 18.

[0047] If plasma is used, it can be direct plasma or remote plasma. In this example, RF generation system 30 generates an RF voltage and outputs it to spray head 14 or substrate support assembly 16 (another is DC ground, AC ground, or floating). By way of example only, RF generation system 30 may include RF voltage generator 32 that generates an RF voltage fed to spray head 14 or substrate support assembly 16 by matching network 34. Alternatively, plasma may be delivered by remote plasma source 36.

[0048] The gas delivery system 40 includes one or more gas sources 42-1, 42-2, ..., 42-N (collectively referred to as gas sources 42), where N is a positive integer. Gas sources 42 supply one or more etching gas mixtures, precursor gas mixtures, cleaning gas mixtures, ashing gas mixtures, etc., to the processing chamber 12. Vaporized precursors may also be used. Gas sources 42 are connected to manifold 48 via valves 44-1, 44-2, ..., 44-N (collectively referred to as valves 44) and mass flow controllers 46-1, 46-2, ..., 46-N (collectively referred to as mass flow controllers 46). The output of manifold 48 is supplied to the processing chamber 12. By way of example only, the output of manifold 48 is supplied to spray heads 14.

[0049] Heater 50 can be connected to a heater coil (not shown) arranged in the substrate support assembly 16. Heater 50 can be used to control the temperature of the substrate support assembly 16 and the substrate 18. Valve 60 and pump 62 can be used to discharge reactants from the processing chamber 12. Controller 70 can be used to control the components of the substrate processing system 10. By way of example only, controller 70 can be used to control the flow of processing gases, monitor processing parameters such as temperature, pressure, and power, activate and extinguish plasma, and remove reactants.

[0050] Figure 1B shows another example of a substrate processing chamber 80 comprising an upper processing chamber 82 and a lower processing chamber 84, the lower processing chamber 84 including a substrate support assembly 16. An induction coil 86 is arranged around the upper processing chamber 82. An RF generation system 30 outputs RF power to the induction coil 86 to generate plasma 88 in the upper processing chamber 82. A spray head 90 filters ions and delivers free radicals to the lower processing chamber 84. The spray head 90 can also be used to supply secondary gases, such as precursor gases from the gas delivery system 40-2, to the lower processing chamber 84.

[0051] Figure 2 shows an example of the substrate support assembly 16 in more detail. The substrate support assembly 16 can be arranged in processing chambers such as those shown in Figures 1 and 2, or any other substrate processing chamber. The substrate support assembly 16 includes a substrate support plate (also called a top plate) 110, support columns 112, and a base 114. The base 114 may include an annular platform or structure (also called a lifting ring, as shown and described in Figure 12) in which the lifting pins and lifting pin support assemblies of this disclosure can be mounted. In some examples, the support columns 112 are movable relative to the base 114.

[0052] The lifting pin bracket assembly 120 (shown generally here and in detail in Figures 10A-11B below) is disposed below the base plate support plate 110 on the base 114. The lifting pin bracket assembly 120 includes a base 126, a lifting pin 130, and a lifting pin bracket 134. In some examples, the lifting pin bracket assembly 120 and the lifting pin 130 are generally cylindrical. The lifting pin 130 includes an annular groove 131 for locking the lifting pin 130 into the lifting pin bracket assembly described below with reference to Figures 10A-11B.

[0053] One or more guide elements 140 may be used to help guide the lifting pin 130. In some examples, the guide element 140 includes a cylindrical support 143 attached to the bottom surface of the substrate support plate 110. The cylindrical support 143 includes a hole 145 for receiving the middle portion of the lifting pin 130. Similarly, the substrate support plate 110 includes a hole 141 (generally shown here, but specifically shown later in Figures 3-8) for receiving the upper portion of the lifting pin 130.

[0054] During use, the base 114 can be raised and lowered relative to the substrate support plate 110 (e.g., using the controller 70 and a suitable actuator) to change the height of the tip of the lifting pin 130 relative to the upper surface of the substrate support plate 110. Therefore, the lifting pin 130 lifts the substrate 122 above the substrate support plate 110 or positions it to receive the substrate 122 for loading the substrate 122 onto the substrate support plate 110. A gap, as shown in 148, is provided between the substrate 122 and the upper surface of the substrate support plate 110.

[0055] When substrate 122 is placed on the upper surface of substrate support plate 110 for processing, a small gap exists between substrate 122 and the upper surface of substrate support plate 110. Processing gas can diffuse through this gap, causing deposition on the back side of substrate 122. Processing gas can also flow through another small gap existing between hole 141 and lifting pin 130, resulting in deposition on the back side of substrate 122, as shown in further detail in FIG3.

[0056] Figure 3-8 shows a ball-lock type lifting pin bracket assembly 120, which is described by way of example only. Any other lifting pin bracket assembly may be used alternatively, such as the fork-type lifting pin bracket assembly shown and described later with reference to Figures 11A and 11B.

[0057] Figure 3 shows the structure of the lifting pin 130 and the hole 141 in more detail. The hole 141 can be cylindrical (as shown in Figure 2) or conical (as shown in Figure 3). Throughout the following description, the hole 141 is conical and is referred to as the conical hole 141. The conical hole 141 tapers downwards like a funnel or in the shape of the letter Y as shown in the figure. As shown, there is a small gap 150 between the cylindrical portion of the lifting pin 130 and the conical hole 141. Process gas can flow through the gap 150, causing deposition on the back side of the substrate 122.

[0058] Furthermore, the lifting pin 130 and the lifting pin bracket assembly 120 are resting on the lifting ring in the base 114 of the substrate support plate 110, regardless of whether the lifting pin 130 is in the raised position (to lift the substrate 122) or in the lowered position (after placing the substrate on the top plate 110). Therefore, when the lifting pin 130 is in the lowered position, the height of the lifting pin 130 (referred to as the lowering height of the lifting pin or the lowering position height) will vary due to factors such as the height of the lifting ring, the thermal expansion of the lifting pin 130 and the various components of the substrate support assembly 16.

[0059] According to the novel lifting pin design disclosed herein, as described below with reference to Figures 4-8, the problem of backside deposition is solved by closing or blocking the flow of processing gas to the back side of substrate 122 and by increasing the repeatability of the lifting pin height relative to substrate support assembly 16 and substrate 122. This lifting pin design makes the height of the lifting pin independent of the height of the lifting ring and the thermal expansion of the various components of substrate support assembly 16.

[0060] Figure 4 shows the design of the lifting pin 200 according to this disclosure. Specifically, the lifting pin 200 has a tapered or tapered tip 202. The tapered tip 202 of the lifting pin 200 (also referred to as the tip or tip portion) engages with a tapered hole 141 in the top plate 110 of the substrate support assembly 16. This engagement of the tapered tip 202 with the tapered hole 141 closes or blocks the lifting pin hole in the top plate 110 leading to the flow of processed gas, as shown at 204.

[0061] The engagement of the tapered tip 202 with the tapered hole 141 also defines the gap or distance between the top surface of the tapered tip 202 and the top surface of the top plate 110 (or the bottom of the substrate 122). When the lifting pin 200 is in the lowered position, the lifting pin 200 is suspended from the tapered hole 141 (at point 204), thereby defining the gap or distance between the top surface of the tapered tip 202 and the top surface of the top plate 110 (or the bottom of the substrate 122).

[0062] The bottom end of the lifting pin 200 is cylindrical and is inserted into the lifting pin support assembly 206. A ball-lock type lifting pin support assembly is shown here only as an example. Any other lifting pin support assembly can be used alternatively, such as the fork-type lifting pin support assembly shown and described with reference to Figures 11A and 11B. The bottom cylindrical portion of the lifting pin includes an annular groove 208. The lifting pin support assembly 206 shown in this example includes a ball lock 210 that engages with the annular groove 208 to securely hold the lifting pin 200 within the lifting pin support assembly 206.

[0063] The lifting ring (shown and described with reference to FIG. 12) in the base 114 of the substrate support assembly 16 includes a plurality of slots 212. The number of slots is equal to the number of lifting pins 200 (e.g., at least 3). Thin pads 214 are arranged in each slot 212. When the lifting ring uses the lifting pins 200 to lift the substrate 122, the lifting pin support assembly 206 rests on the corresponding pads 214.

[0064] The thickness of each shim 214 is selected to compensate for manufacturing tolerances associated with the lifting pin 200, the lifting pin support assembly 206, the slot 212 in the lifting ring, and the lifting ring itself. In other words, when the lifting pin 200 is used to raise (or lower) the substrate 122, the lifting pins 200 need to have equal heights in order to keep the substrate 122 parallel to the top plate 110. Shims 214 of appropriate thickness are used to fine-tune the height of each lifting pin 200 in the raised position, so that the substrate 122 remains parallel to the top plate 110 when raised (or lowered) by the lifting pin 200. For example, the lifting pin 200 and the shims 214 can be made of sapphire.

[0065] The retainer 216 is arranged around the periphery of each pad 214. The retainer 216 is annular. When the lifting pin bracket assembly 206 is placed on the corresponding pad 214 while lifting the base plate 122, the retainer 216 surrounds the lifting pin bracket assembly 206. The retainer 216 can be made of metal (e.g., aluminum) or preferably of ceramic material. Some ceramic materials may have a higher specific gravity than metals (e.g., aluminum). Therefore, using ceramic materials can help reduce the thickness or height of the retainer 216 while still having sufficient weight.

[0066] When in the lowered position, the lifting pin 200 is suspended from the tapered hole 141 by the weight of the lifting pin support assembly 206, which is made of ceramic material. The lifting pin support assembly 206 is suspended above the lifting ring. That is, when the lifting pin 200 is in the lowered position (e.g., after the substrate is placed on the top plate 110), the lifting pin support assembly 206 does not contact the lifting ring and does not rest on the pad 214. During the suspension of the lifting pin 200 from the tapered hole 141, the weight of the retainer 216, made of metal (e.g., aluminum) or ceramic material, securely holds the pad 214 in the slot 212. That is, the weight of the retainer 216 prevents the pad 214 from moving or slipping out of the slot 212.

[0067] Since the lifting pin 200 is suspended from the tapered hole 141 in the descending position and does not contact the lifting ring, the descending height of the lifting pin 200 does not change due to factors including manufacturing tolerances and thermal expansion of various components. Therefore, the positioning of the lifting pin 200 directly relative to the substrate support assembly 16 (i.e., relative to the top plate 110 of the substrate support assembly 16 rather than relative to the lifting ring) provides a more repeatable lifting pin position and height during deposition and other wafer processing.

[0068] Figure 5 shows examples of different views of the lifting pin 200. Features of the lifting pin 200 are shown in detail. For example, different views of the tapered tip 202 of the lifting pin 200 are shown. The annular groove 208 of the lifting pin 200 is also shown in detail.

[0069] Figure 6 shows the lifting pin 200 in the raised or extended position (i.e., the substrate 122 is raised from the top plate 110 of the substrate support assembly 16). In the raised or extended position, the lifting pin bracket assembly 206 is suspended on the lifting pin 200 and rests on the base 114 of the substrate support assembly 16 (more specifically, on the pad 214 in the slot 212 of the lifting ring). To illustrate the contact between the lifting pin bracket assembly 206 and the base 114, other components such as the slot 212, pad 214, and retainer 216, which have already been shown and described with reference to Figure 4, are omitted and will not be described further.

[0070] Figure 7 shows the lifting pin 200 in the lowered position (i.e., after the substrate 122 has been placed on the top plate 110 of the substrate support assembly 16). In the lowered position, the lifting pin bracket assembly 206 is suspended on the lifting pin 200 without contacting or resting on the base 114 of the substrate support assembly 16. Instead, the lifting pin 200 is suspended from the tapered hole 141 (as shown in Figure 4), and the lifting pin bracket assembly 206 is suspended above the base 114. Therefore, there is a gap or distance 220 between the lifting pin bracket assembly 206 and the base 114. To illustrate the separation (i.e., the gap 220) between the lifting pin bracket assembly 206 and the base 114, other details such as the slot 212, the gasket 214, and the retainer 216, which have already been shown and described with reference to Figure 4, are omitted and will not be described further.

[0071] Figure 8 shows a cross-sectional view of the lifting pin bracket assembly 206, in which the lifting pin 200 is inserted. In this view, the lifting pin 200 and the lifting pin bracket assembly 206 are resting (i.e., arranged) on the gasket 214 (i.e., the lifting pin 200 is in the raised position), and the retainer 216 is surrounding the base of the lifting pin bracket assembly 206.

[0072] Figure 9 shows the gasket retainer 216 in more detail. As mentioned above, each gasket 214 used with the corresponding lifting pin 200 and lifting pin bracket assembly 206 can have a different thickness to fine-tune the height of the lifting pin 200 by taking into account the manufacturing tolerances in the lifting pin 200, slot 212 and lifting ring.

[0073] Figures 10A-12 show in detail various examples and components of the lifting pin bracket assembly 206. Figures 10A and 10B show a ball-lock type lifting pin bracket assembly (hereinafter referred to as the ball-lock bracket assembly) used in the examples shown in Figures 4-8. Figures 11A and 11B show a fork-lock type lifting pin bracket assembly (hereinafter referred to as the fork-lock bracket assembly) which can be used to replace the ball-lock bracket assembly shown in Figures 4-8. Figure 12 shows an annular platform (also referred to as a lifting ring) having a slot 212 into which a gasket 214 can be installed. All structures, components, and parts shown in Figures 10A-12 can be made of non-metallic materials. For example, all structures, components, and parts shown in Figures 10A-12 are made of ceramic materials. In addition, the lifting pin 200 is also made of a non-metallic material (e.g., sapphire).

[0074] Figures 10A and 10B show a ball lock bracket assembly 260. The ball lock bracket assembly 260 includes a base 262 and a top (also referred to as a cover) 264. The base 262 includes a ball lock 266, which locks the lifting pin 200 when it is inserted into the base 262. The top 264 is mounted on the base 262 by sliding it down onto the ball lock 266. As the top 264 slides on the ball lock 266, it is locked into the base 262 by an annular element (not shown) that projects radially from a rod portion of the base 262 and mates with a corresponding element (not shown) in the top 264.

[0075] Figure 10A shows the ball lock bracket assembly 260 with its top 264 not fully attached (i.e., not locked) to the base 262. Figure 10B shows the ball lock bracket assembly 260 with its top 264 fully attached (i.e., locked) to the base 262. After the top 264 is fully attached (i.e. locked) to the base 262, the lifting pin 200 can be inserted into the ball lock bracket assembly 260 through the opening 268 in the top 264. After the lifting pin 200 is inserted downward toward the base 262 through the opening 268, the lifting pin 200 is locked into the ball lock bracket assembly 260 by gently pushing it downward on the top 264. The circular groove 208 surrounding the lifting pin 200 (as shown in Figure 4) slides over the ball lock 266 (element 210 in Figure 4) and is locked into the ball lock 266. To unlock and release the lifting pin 200 from the ball lock bracket assembly 260, slightly pull up the top 264, and the lifting pin 200 will be removed from the ball lock bracket assembly 260. The circular groove 208 around the lifting pin 200 will then be unlocked and released from the ball lock 266.

[0076] Figures 11A and 11B show a fork lock bracket assembly 300. The fork lock bracket assembly 300 includes a base 302 and a top (also referred to as a cover) 304. Before mounting the top 304 onto the base 302, a lifting pin 200 is inserted through an opening 306 located at the center of the top 304. By sliding the top 304 down along the lifting pin 200 into the base 302, the top 304 is mounted onto the base 302. The top 304 then slides down the lifting pin 200 toward the base 302. The lifting pin 200 is then locked into and remains locked in the base 302 as described below.

[0077] After the top 304 is mounted on the base 302, the fork lock bracket assembly 300 looks similar to the ball lock bracket assembly 260 shown in FIG. 10B. Therefore, for simplicity, the diagram of the fork lock bracket assembly 300 with the top 304 mounted on the base 302 is not shown. To remove the lifting pin 200 from the fork lock bracket assembly 300, the top 304 is pulled up and removed from the base 302. When the top 304 is pulled up and removed from the base 302, the lifting pin 200 is unlocked from the base 302 (i.e., from the fork lock bracket assembly 300) and can be removed from the base 302.

[0078] Figure 11A shows the base 302 of the fork lock bracket assembly 300 in more detail. Figure 11A shows various views of the base 302. The base 302 includes various views of a cylindrical portion 310 that defines the lower part (or base) of the base 302. The base 302 includes a slot 312 for receiving the lifting pin 130. The slot 312 extends vertically from the cylindrical portion 310. The slot 312 is typically a C-shaped structure that defines a cavity 314 for receiving and retaining the lifting pin 200. The slot 312 is typically a hollow, circular, or elliptical tubular structure, a portion of which is cut and removed along the length (i.e., height) of the slot 312 to make the slot 312 a C-shaped structure. The cavity 314 extends through the slot 312 into the cylindrical portion 310.

[0079] Detail B in Figure 11A shows the design of the slot 312, which allows the lifting pin 200 to be inserted into and held in the base 302 (i.e., in the fork lock bracket assembly 300). The slot 312 has a series of radii that allow the lifting pin 200 to be inserted off-center from the centerline of the base 302 and then slide into the centerline. At the distal end (i.e., the end opposite the cylindrical portion 310), the slot 312 includes a smaller (inner) radius or inner diameter portion that is locked against the annular groove 208 surrounding the lifting pin 200 (as shown in Figure 4). The inner radius or inner diameter portion of the slot 312 near the apex of the slot 312 engages with the annular groove 208 on the lifting pin 200, which locks the lifting pin 200 into the slot 312 and the base 302. The sliding surface of the slot 312 has a radius that matches the insertion portion of the slot 312 and is chamfered both above and below to guide the lifting pin 200 to lock onto the base 302. The outer radius of the slot 312 is matched with the inner radius of the slot 312, so that the top 304 slides down the slot 312 and holds the lifting pin 200 in the cavity 314 in the slot 312.

[0080] Figure 11B shows the top 304 of the fork lock bracket assembly 300 in more detail. The top 304 is cylindrical in shape and includes a hollow structure that matches the slot 312 of the base 302. The top 304 includes an opening 306. The diameter of the opening 306 matches the diameter of the lifting pin 200. The top 304 includes a first cylindrical hollow portion 330 having the diameter of the opening 306 and extending from the opening 306 along the center of the top 304. The top 304 also includes a second cylindrical hollow portion 332 extending from a distance from the opening 306 along the center of the top 304. When the top 304 is mounted on the base 302, the second cylindrical hollow portion 332 matches and surrounds the slot 312 of the base 302. When the top 304 is mounted on the base 302, the opening 306 is aligned with a portion of the cavity 314 near the top of the slot 312.

[0081] Figure 12 schematically shows a slotted annular structure (also called a lifting ring) 400, which can be contained in the base 114 of the substrate support assembly 16 shown in Figure 2. The lifting ring 400 has an inner diameter and an outer diameter. The lifting ring 400 includes a plurality of slots 212. The slots 212 are designed to hold the pads 214 shown in Figures 4-8. For illustrative purposes only, the slots 212 are shown as circular. In practice, the slots 212 can be nearly circular near the outer edge of the lifting ring 400 to allow the pads 214 to slide in and out of the slots 212. Alternatively, the slots can be perfectly circular as shown, and the pads 214 can be inserted into the slots 212 and held in the slots 212 by retainers 216.

[0082] The number of slots 212 is equal to the number of lifting pins 200 used in conjunction with the substrate support assembly 16. For each slot 212, a portion of the lifting ring 400 is removed (etched out or carved) to form a slot 212 with a uniform depth. For example, the slot 212 can be formed by machining or etching a near-circular portion starting from the top surface of the lifting ring 400. The depth of each slot 212 is less than the thickness of the lifting ring 400, and this depth is sufficient to install the gasket 214 into the slot 212. The top of each slot 212 is flush with the top surface of the lifting ring 400. The slot 212 is coplanar with the lifting ring 400.

[0083] The above description is illustrative in nature and is in no way intended to limit the scope of this disclosure, its application, or its uses. The broad teachings of this disclosure can be implemented in various forms. Therefore, although this disclosure contains specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the accompanying drawings, specification, and appended claims. It should be understood that one or more steps within the method can be performed in different orders (or simultaneously) without altering the principles of this disclosure. Furthermore, although each of the embodiments described above is characterized by certain features, any one or more of those features described for any embodiment in this disclosure may be implemented in features of any other embodiment and / or combined with features of other embodiments, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments for each other remains within the scope of this disclosure.

[0084] Various terms are used herein to describe spatial and functional relationships between components (e.g., modules, circuit elements, semiconductor layers, etc.), including "connected," "joined," "coupled," "adjacent," "next to," "above," "under," and "placed between." Unless explicitly stated as "direct," the relationship between the first and second components described above can be a direct relationship where no other intermediate components exist between the first and second components, or an indirect relationship (spatially or functionally) involving one or more intermediate components. As used herein, at least one of the terms A, B, and C should be interpreted using the non-exclusive logical "OR" to represent the logic (A or B or C), and should not be interpreted as representing "at least one A, at least one B, and at least one C."

[0085] In some implementations, the controller is part of the system, which may be part of the examples described above. Such a system may include semiconductor processing equipment comprising one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, airflow systems, etc.). These systems may be integrated with electronic equipment to control operations before, during, and after the processing of semiconductor wafers or substrates. The electronic equipment may be referred to as a "controller," which can control various components or sub-components of one or more systems. Depending on the processing requirements and / or the type of system, the controller may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer tools and other transfer tools, and / or load locks connected to or connected to a specific system.

[0086] In a broad sense, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware storing program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers (e.g., software) that execute program instructions. Program instructions can be instructions passed to the controller in the form of various individual settings (or program files), defining operating parameters for performing specific processes on or for a semiconductor wafer or system. In some embodiments, operating parameters may be part of a recipe defined by a process engineer to complete one or more processing steps during the manufacture of one or more of the following: layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer grains.

[0087] In some implementations, the controller may be part of or coupled to a computer, which may be integrated into, coupled to, or networked with the system, or a combination thereof. For example, the controller may be located in the "cloud" or may be all or part of the wafer fab's mainframe computer system, thus allowing remote access to wafer processing. The computer may initiate remote access to the system to monitor the current progress of manufacturing operations, examine the history of past manufacturing operations, examine trends or performance metrics from multiple manufacturing operations, change parameters of the current process, set process steps to continue the current process, or start a new process. In some examples, the remote computer (e.g., a server) may provide process recipes to the system via a network, which may include a local area network or the Internet. The remote computer may include a user interface that allows parameters and / or settings to be input or programmed, and then transmitted from the remote computer to the system. In some examples, the controller receives instructions in the form of data specifying parameters for each process step to be performed during one or more operations. It should be understood that the parameters are specific to the type of process to be performed and the type of tool the controller uses to interface with or control it. Therefore, as mentioned above, a distributed controller can be implemented, for example, by comprising one or more discrete controllers networked together and operating towards a common purpose, such as the processing and control described herein. An example of a distributed controller for this purpose is one or more integrated circuits in a chamber that communicate with one or more integrated circuits at a remote location (e.g., at the platform level or as part of a remote computer), which combine to control the processing within the chamber.

[0088] System examples may include plasma etching chambers or modules, deposition chambers or modules, spin cleaning chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in semiconductor wafer fabrication and / or production, without any limitation.

[0089] As described above, depending on one or more processing steps the tool needs to perform, the controller may communicate with one or more of the following: other tool circuits or modules, other tool assemblies, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the plant, a main computer, another controller, or a tool for transporting materials to and from the tool location and / or loading port of the semiconductor manufacturing plant.

[0090] 10: Substrate Processing System 12: Processing Room 14: Sprayer Head 16: Substrate support assembly 18:Substrate 30: RF generation system 32: RF voltage generator 34: Matching Network 36: Remote plasma source 40: Gas delivery system 40-2: Gas delivery system 42, 42-1, 42-2, 42-N: Gas source 44, 44-1, 44-2, 44-N: Valve 46, 46-1, 46-2, 46-N: Mass flow controller 48: manifold 50: Heater 60: Valve 62: Pump 70: Controller 80: Substrate Processing Chamber 82: Upper Processing Room 84: Lower Processing Room 86: Induction coil 88: Plasma 90: Spray head 110: Substrate support plate, top plate 112: Support column 114: Base 120: Lifting Pin Bracket Assembly 122:Substrate 126: Base 130: Lifting pin 131: Annular groove 134: Lifting Pin Bracket 140: Guiding element 141: Kong 143: Cylindrical support component 145: Kong 148: Gap 150: Gap 200: Lifting pin 202: Cutting Edge 204: points 206: Lifting Pin Bracket Assembly 208: Annular groove 210: Ball Lock 212: Slot 214: Gasket 216: Fixture 220: Gap or distance 260: Ball Lock Bracket Assembly 262: Base 264: Top 266: Ball Lock 268: Opening 300: Fork Lock Bracket Assembly 302: Base 304: Top 306: Opening 310: Cylindrical section 312: Slot 314: Cavity 330: The first cylindrical hollow section 332: The second cylindrical hollow section

Claims

1. A substrate processing apparatus comprising: a lifting pin for raising and lowering a semiconductor substrate relative to a substrate support assembly in a processing chamber, wherein the lifting pin includes: a tapered top end having a downwardly tapered portion; and a columnar bottom end; and a lifting pin bracket for supporting the bottom end of the lifting pin; a top plate of the substrate support assembly including a hole; and a support structure disposed at a base of the substrate support assembly to support the lifting pin bracket and raise and lower the semiconductor substrate relative to the top plate, wherein when the lifting pin is in a lowered position, the lifting pin bracket is suspended above and separated from the support structure; and wherein... When the lifting pin is in the lowered position, the top end of the lifting pin engages with and hangs from the hole, and the hole is closed due to the weight of the lifting pin bracket suspended above the support structure.

2. The device of claim 1, further comprising: a pad disposed in a slot of the support structure, wherein the lifting pin support rests on the pad when the support structure raises the lifting pin to lift the semiconductor substrate from the top plate; and a retainer disposed on the pad surrounding the lifting pin support when the lifting pin rests on the pad.

3. The device of claim 1, wherein the hole in the top plate is conical and tapers downward, wherein when the lifting pin is in the lowered position, the conical hole supports the top of the lifting pin, and the lifting pin hangs from the conical hole.

4. The device of claim 3, wherein, in the lowered position, the top end of the lifting pin is suspended from the conical hole at a predetermined distance from one of the top surfaces of the top plate of the substrate support assembly.

5. The device as requested in item 1, wherein the support structure is a ring structure.

6. The device of claim 5, wherein the hole in the top plate is conical and tapers downward and wherein, when in the lowered position: the lifting pin bracket supporting the bottom end of the lifting pin is suspended above the annular structure.

7. The device of claim 6, further comprising a pad disposed in a slot of the annular structure, wherein the lifting pin support rests on the pad when the annular structure raises the lifting pin to lift the semiconductor substrate from the top plate.

8. The device of claim 7, further comprising an annular retainer disposed on the gasket.

9. The device of claim 8, wherein when the lifting pin bracket rests on the pad, the annular retainer surrounds a base of the lifting pin bracket.

10. The device of claim 1, wherein the lifting pin further includes a groove near the bottom end, and wherein the lifting pin bracket includes a ball lock to lock into the groove.

11. The device of claim 2, wherein the lifting pin, the lifting pin bracket, the gasket, and the retainer are made of a ceramic material.

12. A substrate processing system comprising: a plurality of lifting pins for raising and lowering a semiconductor substrate relative to a substrate support assembly in a processing chamber, wherein each lifting pin includes: a top end having a downwardly tapered cone shape; and a bottom end having a column shape; and a plurality of lifting pin supports, each lifting pin support being used to support the bottom end of a corresponding lifting pin; a top plate of the substrate support assembly including a plurality of downwardly tapered conical holes; and an annular structure disposed at a base of the substrate support assembly to support the lifting pin supports and raise and lower the semiconductor substrate relative to the top plate, wherein when the lifting pins are in a lowered position, the lifting pin supports are suspended above and separated from the annular structure; and wherein when the lifting pins are in the lowered position, the top ends of the lifting pins hang from the conical holes, and the conical holes are closed due to the weight of the lifting pin supports suspended above the annular structure.

13. The system of claim 12, further comprising: a plurality of pads respectively disposed in a plurality of slots of the annular structure, wherein when the annular structure raises the lifting pins to lift the semiconductor substrate from the top plate, the lifting pin supports are resting on each of the plurality of pads, and wherein the raised semiconductor substrate is parallel to the top plate.

14. The system of claim 13 further comprises: a plurality of retainers disposed on each of the plurality of gaskets, wherein when the lifting pin supports rest on the gaskets, the retainers surround each of the lifting pin supports.

15. A lifting pin comprising: a first conical portion; a second portion extending from the first conical portion; and a third columnar portion including a groove, the third columnar portion extending from the second portion and inserted into a bracket, the bracket including a ball lock locking into the groove.

16. A lifting pin assembly comprising: a lifting pin for raising and lowering a semiconductor substrate relative to a substrate support assembly in a processing chamber, wherein the lifting pin includes: a tapered top end having a downwardly tapered shape; a columnar bottom end; and a groove near the bottom end; and a lifting pin bracket for supporting the bottom end of the lifting pin, wherein the lifting pin bracket includes a ball lock for locking into the groove.

17. A system comprising the lifting pin assembly and substrate support assembly of claim 16, wherein the substrate support assembly includes a top plate having a downwardly tapered hole, wherein when the lifting pin is in a lowered position, the lifting pin is suspended from a top surface of the top plate at a predetermined distance from the top surface of the top plate, with the top end of the lifting pin supported by the tapered hole.

18. A system comprising the lifting pin assembly of claim 16, the system further comprising: a top plate of the substrate support assembly, the top plate including a downwardly tapered aperture, wherein when the lifting pin is in a lowered position, the tip of the lifting pin is suspended from the tapered aperture; and an annular structure disposed at a base of the substrate support assembly to support the lifting pin support and to raise and lower the semiconductor substrate relative to the top plate, wherein when the lifting pin is in the lowered position, the lifting pin support is suspended above the annular structure.

19. The system of claim 18, further comprising: a pad disposed in a slot of the annular structure, wherein the lifting pin support rests on the pad when the annular structure raises the lifting pin to lift the semiconductor substrate from the top plate; and a retainer disposed on the pad surrounding the lifting pin support when the lifting pin rests on the pad.

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