Wafer lift pin mechanism for preventing localized backside deposition

Abstract

To provide a wafer lift pin which prevents deposition on the rear surface of a wafer by preventing local flow of process gas to the rear surface of the wafer and suppressing variation in lift pin gap with respect to the wafer.SOLUTION: The substrate support assembly comprises lift pins 200 for raising and lowering a semiconductor substrate 122 relative to a substrate support plate 110 in the processing chamber. The lift pin includes a tip 202 having a downwardly tapered conical shape and a lower end portion having a cylindrical shape. The substrate support assembly includes a lift pin holder assembly 206 that holds the lower ends of the lift pins.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Application No. 62 / 978,914, filed February 20, 2020, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates generally to substrate processing systems, and more particularly to a lift pin mechanism for preventing localized backside deposition on semiconductor wafers. [Background technology]

[0003] The background discussion provided herein is intended to provide a general overview of the contents of the present disclosure. The work of the presently named inventors, as well as aspects of the specification that may not otherwise qualify as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art to the present disclosure to the extent that they are described in this Background section.

[0004] Substrate processing systems may be used to deposit, etch, ash, clean, or otherwise process films on substrates, such as semiconductor wafers. Substrate processing systems typically include a processing chamber, a gas distribution apparatus, and a substrate support assembly. During processing, the substrate is placed on the substrate support assembly. Various gas mixtures may be introduced into the processing chamber. Radio frequency (RF) plasma and / or heat may be used to activate chemical reactions.

[0005] Lift pins may be used to load and remove substrates from a processing chamber by a robotic arm. Typically, the upper ends of the lift pins are flush with or below the top surface of the substrate support assembly. The lower ends of the lift pins are located and held within a lift pin holder. When loading or unloading a substrate, the lift pins rise relative to the top surface of the substrate support assembly to lift the substrate and provide clearance between the substrate and the substrate support assembly. The clearance between the substrate and the substrate support assembly allows for insertion and removal of an end effector of the robotic arm. Summary of the Invention

[0006] The apparatus includes lift pins for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber, the lift pins having an upper end with a downwardly tapering conical shape and a lower end with a cylindrical shape, and a lift pin holder for holding the lower end of the lift pin.

[0007] In other features, the apparatus further comprises a top plate of the substrate support assembly including a conical bore that tapers downwardly, with the upper ends of the lift pins suspended from the conical bore when the lift pins are in the lower position, and a ring-shaped structure disposed at the base of the substrate support assembly for supporting a lift pin holder and for raising and lowering the semiconductor substrate relative to the top plate, with the lift pin holder suspended above the ring-shaped structure when the lift pins are in the lower position.

[0008] In other features, the apparatus further includes a shim disposed in the slot of the ring-shaped structure, the lift pin holder resting on the shim when the ring-shaped structure raises the lift pins to lift the semiconductor substrate from the top plate, and a retainer surrounding the lift pin holder when the lift pin holder rests on the shim and positioned on the shim.

[0009] In other features, the substrate support assembly includes a top plate having a downwardly tapering conical bore from which the lift pins are suspended, with the conical bore supporting the upper ends of the lift pins when the lift pins are in a lowered position.

[0010] In another feature, in the lower position, the upper ends of the lift pins are suspended from the conical bores at a predetermined distance from the upper surface of the top plate of the substrate support assembly.

[0011] In other features, the apparatus further comprises a ring-shaped structure disposed at a base of the substrate support assembly for supporting the lift pin holder and for raising and lowering the semiconductor substrate relative to the substrate support assembly.

[0012] In another feature, in the lower position, the upper ends of the lift pins are suspended from downwardly tapering conical bores within the top plate of the substrate support assembly, and a lift pin holder that holds the lower ends of the lift pins is suspended above a ring-shaped structure.

[0013] In other features, the apparatus further comprises a shim disposed in the slot of the ring-shaped structure, wherein the lift pin holder rests on the shim when the ring-shaped structure raises the lift pins to lift the semiconductor substrate off the top plate.

[0014] In other features, the device further comprises an annular retainer disposed over the shim.

[0015] In another feature, an annular retainer surrounds a base portion of the lift pin holder when the lift pin holder is placed on the shim.

[0016] In other features, the lift pin further comprises a groove proximate the lower end, and the lift pin holder comprises a ball lock for securing within the groove.

[0017] In other features, the lift pins, lift pin holders, shims, and retainers are made from a ceramic material.

[0018] In yet another feature, a system includes a plurality of lift pins for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber. Each lift pin includes an upper end having a downwardly tapered conical shape and a lower end having a cylindrical shape. The system further includes a plurality of lift pin holders. Each lift pin holder is configured to hold a respective lower end of a lift pin. The system further includes a top plate of the substrate support assembly including a plurality of downwardly tapered conical bores. The upper ends of the lift pins are suspended from the conical bores when the lift pins are in a lower position. The system further includes a ring-shaped structure disposed at a base of the substrate support assembly for supporting the lift pin holder and for raising and lowering the semiconductor substrate relative to the top plate. The lift pin holder is suspended above the ring-shaped structure when the lift pins are in a lower position.

[0019] In other features, the system further includes a plurality of shims respectively disposed in the plurality of slots of the ring-shaped structure, and the lift pin holder is placed on each shim when the ring-shaped structure raises the lift pins to raise the semiconductor substrate from the top plate, so that the raised semiconductor substrate is parallel to the top plate.

[0020] In other features, the system further includes a plurality of retainers disposed on each of the shims, the retainers surrounding each of the lift pin holders when the lift pin holders are placed on the shims.

[0021] In yet another feature, the lift pin includes a first conical portion, a second portion extending from the first conical portion, and a third cylindrical portion including a groove, the third cylindrical portion extending from the second portion and inserted into a holder including a ball lock that secures within the groove.

[0022] In still other features, a lift pin assembly includes lift pins for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber, and a lift pin holder for holding a lower end of the lift pin. The lift pin has an upper end having a downwardly tapering conical shape and a lower end having a cylindrical shape. The lift pin includes a groove adjacent to the lower end. The lift pin holder includes a ball lock for securing within the groove.

[0023] In still other features, a system includes a lift pin assembly and a substrate support assembly, the substrate support assembly including a top plate having a downwardly tapering conical bore, the lift pins suspended from the conical bore a predetermined distance above an upper surface of the top plate, with the conical bore supporting upper ends of the lift pins when the lift pins are in a lowered position.

[0024] In yet another example, a system includes a lift pin assembly and a top plate of a substrate support assembly. The top plate of the substrate support assembly includes a conical bore that tapers downward. Upper ends of the lift pins are suspended from the conical bore when the lift pins are in a lowered position. The system further includes a ring-shaped structure disposed at a base of the substrate support assembly for supporting a lift pin holder and for raising and lowering the semiconductor substrate relative to the top plate. The lift pin holder is suspended above the ring-shaped structure when the lift pins are in a lowered position.

[0025] In still other features, the system further includes a shim and a retainer. The shim is disposed within the slot of the ring-shaped structure. The lift pin holder rests on the shim when the ring-shaped structure raises the lift pins to lift the semiconductor substrate off the top plate. The retainer is disposed on the shim to surround the lift pin holder when the lift pin holder rests on the shim.

[0026] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0027] The present disclosure will become more fully understood from the detailed description and the accompanying drawings below.

[0028] [Figure 1A] FIG. 1A is a diagram illustrating an example of a substrate processing system. [Figure 1B] FIG. 1B is a diagram illustrating an example of a substrate processing system.

[0029] [Figure 2] FIG. 2 illustrates an example of a substrate support assembly that may be used in the substrate processing system of FIGS. 1A and 1B.

[0030] [Figure 3] FIG. 3 illustrates a first example of a lift pin for use with the substrate support assembly of FIG.

[0031] [Figure 4] FIG. 4 illustrates a second example of a lift pin for use with the substrate support assembly of FIG.

[0032] [Figure 5] FIG. 5 shows a second example of a lift pin in more detail.

[0033] [Figure 6] FIG. 6 shows the second lift pin in the upper position.

[0034] [Figure 7] FIG. 7 shows the second lift pin in a lower position.

[0035] [Figure 8]FIG. 8 is a cross-sectional view of the second lift pin, the lift pin holder assembly, the shim, and the shim retainer.

[0036] [Figure 9] FIG. 9 shows the shim retainer in more detail.

[0037] [Figure 10A] FIG. 10A illustrates a ball-lock lift pin holder assembly for use with the substrate support assembly of FIG. [Figure 10B] FIG. 10B illustrates a ball-lock lift pin holder assembly for use with the substrate support assembly of FIG.

[0038] [Figure 11A] FIG. 11A illustrates a fork-lock lift pin holder assembly for use with the substrate support assembly of FIG. [Figure 11B] FIG. 11B illustrates a fork-lock lift pin holder assembly for use with the substrate support assembly of FIG.

[0039] [Figure 12] FIG. 12 is a schematic diagram of a slotted lift ring for use with the substrate support assembly of FIG.

[0040] In the drawings, reference numbers may be reused to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0041] This disclosure provides a novel wafer lift pin design that prevents deposition on the backside of the wafer in proximity to the lift pin holes in the ESC pedestal. This lift pin design prevents localized process gas flow to the backside of the wafer and reduces variations in the lift pin gap to the wafer, thereby preventing deposition on the backside of the wafer.

[0042] Typically, the lift pins pass through circular holes or bores in the pedestal, where they can contact and lift the wafer. The holes through which the lift pins pass provide clearance for the lift pins. The lift pins are cylindrical, allowing process gases to reach the backside of the wafer. Also, when the lift pins are in their lowered position, their height is relative to a movable ring, which is several inches away. Therefore, the height of the lift pins relative to the wafer depends on many factors, including the height of the movable ring and the thermal expansion of the lift pin and pedestal assembly.

[0043] The lift pin design disclosed herein solves the problem of backside deposition by both blocking the flow of process gas to the wafer backside and increasing the repeatability of the lift pin height relative to the pedestal and wafer. Specifically, the lift pins have tapered tips that engage matching tapered features in the lift pin holes in the pedestal. This engaged taper seals the lift pin holes against the flow of process gas. This taper also determines the height of the lift pin relative to the pedestal surface by utilizing the tapered pedestal holes to set the lift pin height when the lift pins are in the lower position. Specifically, while the lift pins are in the lower position, the tapered tips of the lift pins are suspended from the tapered pedestal holes, and the lift pins do not contact the lift ring that moves them to the upper position. This eliminates variations in lift pin height caused by factors such as actuator position, manufacturing tolerances, and thermal expansion of various components.

[0044] The lift pins of the present disclosure are depressed into the pedestal by attaching a ceramic weight (e.g., ceramic lift pin holder) assembly to the bottom of the lift pin. This weight assembly is made entirely of ceramic material to prevent corrosion, thereby preventing wafer placement and defect issues. The ceramic weight assembly is easily removable from the bottom of the lift pin with a single hand operation. This maintains the ability of the lift pin to be removable from the top surface of the pedestal for easy disassembly and maintenance. For example, the ceramic weight assembly may include a ball-lock lift pin holder or a fork-lock lift pin holder made of ceramic material.

[0045] For example, the lift pins of the present disclosure are made of sapphire. The conical tips of the lift pins have intricate features machined into them to precisely set the lift pin's lower elevation. The lift ring determines the lift pin's upper elevation. The upper elevation of each lift pin is further adjusted with thin sapphire shims. Each shim is held in place by a metal or ceramic ring that acts as a weight to prevent the shim from exiting its corresponding hole in the lift ring. Ceramic rings can be made thinner than metal rings and do not corrode, preventing contamination issues. The conical tips of the lift pins are used to block the lift pin holes, preventing the flow of process gases against the backside of the wafer. Positioning the lift pins directly relative to the pedestal allows for more repeatable lift pin positioning during deposition and any other wafer processing. These and other features of the lift pin design are described in more detail below.

[0046] The present disclosure is organized as follows: First, an example substrate processing system is shown and described with reference to FIGS. 1A and 1B. An example substrate support assembly including lift pins and a lift pin holder assembly is shown and described with reference to FIG. 2. Example lift pin designs, along with lift pin holder assemblies, are shown and described with reference to FIGS. 3-9. A ball-lock lift pin holder assembly is shown and described with reference to FIGS. 10A and 10B. A fork-lock lift pin holder assembly is shown and described with reference to FIGS. 11A and 11B. A ring-shaped platform (i.e., lift ring) having slots into which shims can be installed is shown and described with reference to FIG. 12. While only two example substrate processing systems are shown, the lift pin designs described herein can be used in other types of substrate processing systems.

[0047] 1A shows a substrate processing system 10 including a processing chamber 12 that contains an RF plasma (if used) and surrounds other components of the substrate processing system 10. The substrate processing system 10 includes a showerhead 14 and a substrate support assembly 16. A substrate 18 is disposed on the substrate support assembly 16. The showerhead 14 introduces and distributes process gases during processing of the substrate 18.

[0048] If a plasma is used, the plasma can be a direct plasma or a remote plasma. In this example, an RF generation system 30 generates and outputs an RF voltage to either the showerhead 14 or the substrate support assembly 16 (with the other being connected to digital ground, analog ground, or floating). By way of example only, the RF generation system 30 may include an RF voltage generator 32 that generates an RF voltage that is supplied to the showerhead 14 or the substrate support assembly 16 by a matching network 34. Alternatively, the plasma may be supplied by a remote plasma source 36.

[0049] The gas delivery system 40 includes one or more gas sources 42-1, 42-2, ..., 42-N (collectively, gas sources 42), where N is a positive integer. The gas sources 42 deliver 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. The gas sources 42 are connected to a manifold 48 by valves 44-1, 44-2, ..., 44-N (collectively, valves 44) and mass flow controllers 46-1, 46-2, ..., 46-N (collectively, mass flow controllers 46). The output of the manifold 48 is delivered to the processing chamber 12. By way of example only, the output of the manifold 48 is delivered to the showerhead 14.

[0050] A heater 50 may be connected to a heater coil (not shown) disposed on the substrate support assembly 16. The heater 50 may be used to control the temperature of the substrate support assembly 16 and the substrate 18. Valves 60 and pumps 62 may be used to evacuate reactants from the processing chamber 12. A controller 70 may be used to control components of the substrate processing system 10. By way of example only, the controller 70 may be used to control the flow of process gases, monitor process parameters such as temperature, pressure, and power, strike and extinguish the plasma, remove reactants, etc.

[0051] 1B shows another example of a substrate processing chamber 80 including an upper chamber 82 and a lower chamber 84, which contain a substrate support assembly 16. An inductive coil 86 is disposed around the upper chamber 82. An RF generation system 30 outputs RF power to the inductive coil 86 to generate a plasma 88 within the upper chamber 82. A showerhead 90 filters ions and delivers radicals to the lower chamber 84. The showerhead 90 may also be used to deliver a secondary gas, such as a precursor gas, from a gas delivery system 40-2 to the lower chamber 84.

[0052] FIG. 2 shows an example of a substrate support assembly 16 in more detail. The substrate support assembly 16 may be disposed within a processing chamber such as that shown in FIGS. 1A and 1B or any other substrate processing chamber. The substrate support assembly 16 includes a substrate support plate (also referred to as a top plate) 110, support posts 112, and a base 114. The base 114 may include a ring-shaped platform or structure (also referred to as a lift ring, shown and described with reference to FIG. 12) within which the lift pins and lift pin holder assemblies of the present disclosure may be mounted. In some examples, the support posts 112 move relative to the base 114.

[0053] Lift pin holder assembly 120 (shown generally here and more specifically in FIGS. 10A-11B below) is disposed below substrate support plate 110 on base 114. Lift pin holder assembly 120 includes a base portion 126, lift pins 130, and lift pin holders 134. In some examples, lift pin holder assembly 120 and lift pins 130 are generally cylindrical. Lift pins 130 include circular grooves 131 that are useful for securing lift pins 130 within the lift pin holder assembly, which will be described below with reference to FIGS. 10A-11B below.

[0054] One or more guide elements 140 may be used to help guide the lift pins 130. In some examples, the guide elements 140 include cylindrical supports 143 attached to the bottom surface of the substrate support plate 110. The cylindrical supports 143 include bores 145 for accommodating the middle portions of the lift pins 130. Similarly, the substrate support plate 110 includes bores 141 (shown generally here and more specifically in Figures 3-8 below) for accommodating the upper portions of the lift pins 130.

[0055] In use, the base 114 may be raised and lowered (e.g., using the controller 70 and suitable actuators) relative to the substrate support plate 110 to vary the height of the upper ends of the lift pins 130 relative to the upper surface of the substrate support plate 110. As a result, the lift pins 130 are positioned to either lift the substrate 122 above the substrate support plate 110 or to receive and mount the substrate 122 on the substrate support plate 110. A clearance is provided between the substrate 122 and the upper surface of the substrate support plate 110, as indicated at 148.

[0056] When the substrate 122 is placed on the upper surface of the substrate support plate 110 for processing, a small gap exists between the substrate 122 and the upper surface of the substrate support plate 110. Process gases can diffuse through this gap and cause deposition on the backside of the substrate 122. Process gases can also flow through another small gap that exists between the bore 141 and the lift pins 130, shown in more detail in FIG. 3, causing deposition on the backside of the substrate 122.

[0057] 3-8, a ball-lock style lift pin holder assembly 120 is shown and described by way of example only. Any other lift pin holder assembly may be used instead, such as the fork style lift pin holder assembly shown and described below with reference to FIGS. 11A and 11B.

[0058] FIG. 3 shows the structure of the lift pin 130 and the bore 141 in more detail. The shape of the bore 141 can be cylindrical (as shown in FIG. 2) or conical (as shown in FIG. 3). Throughout the following description, the bore 141 is conical in shape and will be referred to as a conical bore 141. The conical bore 141 tapers downward, like a funnel or Y, as shown. A small gap 150 exists between the lift pin 130 and the cylindrical portion of the conical bore 141, as shown. Process gases can flow through the gap 150, causing deposition on the backside of the substrate 122.

[0059] Furthermore, the lift pins 130 and lift pin holder assembly 120 rest on a lift ring within the base 114 of the substrate support plate 110, whether the lift pins 130 are in the upper position (to raise the substrate 122) or the lower position (after placing the substrate on the top plate 110). As a result, the height of the lift pins 130 when they are in the lower position (referred to as the lift pin lower height or lower position height) varies depending on factors such as the height of the lift ring and the thermal expansion of the lift pins 130 and various components of the substrate support assembly 16.

[0060] 4-8, a novel lift pin design according to the present disclosure solves the problem of backside deposition by closing off or blocking the flow of process gas to the backside of the substrate 122 and increasing the repeatability of the lift pin height relative to the substrate support assembly 16 and the substrate 122. This lift pin design makes the lift pin height independent of the height of the lift ring and the thermal expansion of the various components of the substrate support assembly 16.

[0061] 4 illustrates a lift pin 200 design in accordance with the present disclosure. Specifically, the lift pin 200 has a conical or tapered tip 202. The conical tip 202 (also referred to as the top end or apex) of the lift pin 200 engages with a conical bore 141 in the top plate 110 of the substrate support assembly 16. This engagement between the conical tip 202 and the conical bore 141 closes or blocks the lift pin hole in the top plate 110 to the flow of process gases, as shown at 204.

[0062] This engagement of conical tip 202 with conical bore 141 also defines a gap or distance between the top surface of conical tip 202 and the top surface of top plate 110 (or the bottom of substrate 122). When lift pin 200 is in the lower position, lift pin 200 is suspended from conical bore 141 (at point 204), which defines a gap or distance between the top surface of conical tip 202 and the top surface of top plate 110 (or the bottom of substrate 122).

[0063] The lower end of the lift pin 200 is cylindrical and is inserted into a lift pin holder assembly 206. A ball-lock type lift pin holder assembly is shown by way of example only. Any other lift pin holder assembly, such as the fork-type lift pin holder assembly shown and described with reference to Figures 11A and 11B, may be used instead. The bottom cylindrical portion of the lift pin includes a circular groove 208. The lift pin holder assembly 206 in the illustrated example includes a ball lock 210 that engages with the circular groove 208 to securely hold the lift pin 200 in the lift pin holder assembly 206.

[0064] The lift ring (shown and described with reference to FIG. 12 ) of the base 114 of the substrate support assembly 16 includes a plurality of slots 212. The number of slots is the same as the number of lift pins 200 (e.g., at least three). A thin shim 214 is disposed in each slot 212. When the lift ring uses each lift pin 200 to raise the substrate 122, the lift pin holder assembly 206 rests on the corresponding shim 214.

[0065] The thickness of each shim 214 is selected to compensate for manufacturing tolerances associated with the lift pins 200, the lift pin holder assembly 206, the slots 212 in the lift ring, and the lift ring itself. That is, the lift pins 200 must be at the same height to hold the substrate 122 parallel to the top plate 110 when the lift pins 200 are used to raise (or lower) the substrate 122. Shims 214 of the appropriate thickness are used to fine-tune the height of each lift pin 200 in the upper position so that the substrate 122 is held parallel to the top plate 110 when raised (or lowered) by the lift pins 200. For example, the lift pins 200 and shims 214 can be made of sapphire.

[0066] A retainer 216 is disposed on the outer periphery and periphery of each shim 214. The retainer 216 has an annular shape. The retainer 216 surrounds the lift pin holder assembly 206 when the lift pin holder assembly 206 rests on the corresponding shim 214 while the substrate 122 is being raised. The retainer 216 can be made of a metal (e.g., aluminum) or, preferably, a ceramic material. Some ceramic materials may have a higher specific gravity than metals such as aluminum. Therefore, the use of a ceramic material helps reduce the thickness or height of the retainer 216 while retaining sufficient weight.

[0067] When in the lower position, the lift pin 200 is suspended from the conical bore 141 by the weight of a lift pin holder assembly 206 made of a ceramic material. The lift pin holder assembly 206 is suspended above the lift ring. That is, the lift pin holder assembly 206 does not contact the lift ring and does not rest on the shim 214 when the lift pin 200 is in the lower position (e.g., after a substrate is placed on the top plate 110). While the lift pin 200 is suspended from the conical bore 141, the weight of a retainer 216 made of a metal (e.g., aluminum) or ceramic material securely holds the shim 214 in the slot 212. That is, the weight of the retainer 216 prevents the shim 214 from moving or slipping out of the slot 212.

[0068] Because the lift pins 200 are suspended from the conical bore 141 in a downward position and the lift pins 200 do not contact the lift ring, the downward height of the lift pins 200 does not vary due to factors such as manufacturing tolerances and thermal expansion of various components. Thus, positioning the lift pins 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 lift ring) results in more repeatable lift pin position and height during deposition and other wafer processing.

[0069] 5 shows an example of a lift pin 200 from various perspectives. Features of the lift pin 200 are shown in detail. For example, various perspectives of the conical tip 202 of the lift pin 200 are shown. The circular groove 208 of the lift pin 200 is shown in detail.

[0070] 6 shows the lift pins 200 in an upper or raised position (i.e., with the substrate 122 raised from the top plate 110 of the substrate support assembly 16). In the upper or raised position, the lift pin holder assembly 206 is suspended from the lift pins 200, which are resting on the base 114 of the substrate support assembly 16 (more specifically, on shims 214 in slots 212 in the lift ring). For purposes of illustrating the contact between the lift pin holder assembly 206 and the base 114, other elements already shown and described with reference to FIG. 4, such as the slots 212, shims 214, and retainers 216, have been omitted.

[0071] 7 shows the lift pins 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 lift pin holder assemblies 206 are suspended from the lift pins 200, which do not contact or rest on the base 114 of the substrate support assembly 16. Instead, the lift pins 200 are suspended from the conical bores 141 (as shown in FIG. 4), and the lift pin holder assemblies 206 are suspended above the base 114. As a result, a gap or distance 220 exists between the lift pin holder assemblies 206 and the base 114. To illustrate the separation (i.e., gap 220) between the lift pin holder assemblies 206 and the base 114, other details already shown and described with reference to FIG. 4 have been omitted, such as the slots 212, shims 214, and retainers 216.

[0072] 8 is a cross-sectional view of lift pin holder assembly 206 with lift pin 200 inserted into lift pin holder assembly 206. In this view, lift pin 200 and lift pin holder assembly 206 rest (i.e., are positioned) on shim 214 (i.e., lift pin 200 is in the upper position), and retainer 216 surrounds the base portion of lift pin holder assembly 206.

[0073] 9 shows shim retainer 216 in further detail. As mentioned above, each shim 214 used with a corresponding lift pin 200 and lift pin holder assembly 206 may have a different thickness to fine-tune the height of the lift pin 200 by accounting for manufacturing tolerances of the lift pin 200, slot 212, and lift ring.

[0074] FIGS. 10A-12 detail various examples and components of the lift pin holder assembly 206. FIGS. 10A and 10B illustrate a ball-lock type lift pin holder assembly (hereinafter referred to as the "ball-lock holder assembly") used in the examples shown in FIGS. 4-8. FIGS. 11A and 11B illustrate a fork-lock type lift pin holder assembly (hereinafter referred to as the "fork-lock holder assembly") that can be used in place of the ball-lock holder assembly shown in FIGS. 4-8. FIG. 12 illustrates a ring-shaped platform (also referred to as a lift ring) having slots 212 into which shims 214 can be installed. All of the structures, assemblies, and components shown in FIGS. 10A-12 are made of non-metallic materials. For example, all of the structures, assemblies, and components shown in FIGS. 10A-12 are made of ceramic materials. Furthermore, the lift pins 200 are also made of non-metallic materials (e.g., sapphire).

[0075] 10A and 10B show a ball-lock holder assembly 260. The ball-lock holder assembly 260 includes a base portion 262 and a top portion (also referred to as a cap) 264. The base portion 262 includes a ball lock 266 for securing the lift pin 200 when the lift pin 200 is inserted into the base portion 262. The top portion 264 is installed on the base portion 262 by sliding the top portion 264 down over the ball lock 266. Once the top portion 264 is slid over the ball lock 266, the top portion 264 is secured within the base portion 262 via a ring-shaped element (not shown) that protrudes radially from the axis of the base portion 262 and mates with a corresponding element (not shown) within the top portion 264.

[0076] FIG. 10A shows the ball-lock holder assembly 260 with the upper portion 264 not fully seated on (i.e., not internally secured within) the base portion 262. FIG. 10B shows the ball-lock holder assembly 260 with the upper portion 264 fully seated on (i.e., internally secured within) the base portion 262. With the upper portion 264 fully seated on (i.e., internally secured within) the base portion 262, the lift pin 200 can be inserted into the ball-lock holder assembly 260 through an opening 268 in the upper portion 264. After the lift pin 200 is inserted downward through the opening 268 toward the base portion 262, the lift pin 200 is secured within the ball-lock holder assembly 260 by pressing down slightly on the upper portion 264. The circular groove 208 (shown in FIG. 4) around the periphery of the lift pin 200 slides over and secures within the ball lock 266 (element 210 in FIG. 4). To unlock and release the lift pin 200 from the ball-lock holder assembly 260, the top portion 264 is pulled up slightly and the lift pin 200 is removed from the ball-lock holder assembly 260. The circular groove 208 around the periphery of the lift pin 200 unlocks and releases the ball lock 266.

[0077] 11A and 11B show a fork lock holder assembly 300. The fork lock holder assembly 300 includes a base portion 302 and an upper portion (also referred to as a cap) 304. Before the upper portion 304 is placed on the base portion 302, the lift pins 200 are inserted through central openings 306 in the upper portion 304. The upper portion 304 is placed on the base portion 302 by sliding the upper portion 304, along with the lift pins 200, down into the base portion 302. The upper portion 304 is then slid down on the lift pins 200 toward the base portion 302. The lift pins 200 are secured within the base portion 302 and remain secured therein, as described below.

[0078] After the upper portion 304 is installed on the base portion 302, the fork-lock holder assembly 300 appears very similar in appearance to the ball-lock holder assembly 260 shown in FIG. 10B. Therefore, for simplicity, a view of the fork-lock holder assembly 300 with the upper portion 304 installed on the base portion 302 is not shown again. To remove the lift pin 200 from the fork-lock holder assembly 300, the upper portion 304 is pulled up and away from the base portion 302. Once the upper portion 304 is pulled up and away from the base portion 302, the lift pin 200 is unlocked from the base portion 302 (i.e., from the fork-lock holder assembly 300) and can be removed from the base portion 302.

[0079] FIG. 11A shows the base portion 302 of the fork lock holder assembly 300 in greater detail. FIG. 11A shows various views of the base portion 302. The base portion 302 includes a cylindrical portion 310 that defines the lower portion (or base) of the base portion 302. The base portion 302 includes a slot 312 for receiving the lift pin 130. The slot 312 extends perpendicularly from the cylindrical portion 310. The slot 312 is generally a C-shaped structure that defines a cavity 314 that receives and retains the lift pin 200 therein. The slot 312 is generally a hollow, circular or oval, tubular structure, with a portion of the tubular structure sliced ​​and removed along the length (i.e., height) of the slot 312 to create the C-shaped structure. The cavity 314 extends through the slot 312 into the cylindrical portion 310.

[0080] Detail B of FIG. 11A shows the design of slot 312, which allows lift pin 200 to be inserted and retained within base portion 302 (i.e., within fork lock holder assembly 300). Slot 312 has a continuous radius that allows lift pin 200 to be inserted off-center from the centerline of base portion 302 and then slide back to the centerline. At its distal end (i.e., the end opposite cylindrical portion 310), slot 312 includes a smaller (inner) radius or portion that locks into circular groove 208 around the periphery of lift pin 200 (shown in FIG. 4). The inner radius or portion near the top of slot 312 engages with circular groove 208 on lift pin 200, locking lift pin 200 within slot 312 and base portion 302. The sliding surface of slot 312 has a radius that matches the insertion portion of slot 312 and is chamfered both above and below to guide lift pin 200 as it locks relative to base portion 302. The outer radius of the slot 312 matches the inner radius of the top portion 304 so that the top portion 304 slides down the slot 312 to retain the lift pin 200 within a cavity 314 within the slot 312 .

[0081] 11B shows the upper portion 304 of the fork lock holder assembly 300 in more detail. The upper portion 304 is cylindrical and includes a hollow structure that mates with the slot 312 in the base portion 302. The upper portion 304 includes an opening 306. The diameter of the opening 306 matches the diameter of the lift pin 200. The upper portion 304 includes a first cylindrical hollow portion 330 that has the diameter of the opening 306 and extends from the opening 306 along the center of the upper portion 304. The upper portion 304 further includes a second cylindrical hollow portion 332 that extends from a position away from the opening 306 along the center of the upper portion 304. The second cylindrical hollow portion 332 mates with and surrounds the slot 312 in the base portion 302 when the upper portion 304 is installed on the base portion 302. The opening 306 aligns with a portion of the cavity 314 near the apex of the slot 312 when the top 304 is placed on the base 302 .

[0082] FIG. 12 schematically illustrates a slotted annular structure (also referred to as a lift ring) 400 that may be included in the base 114 of the substrate support assembly 16 shown in FIG. 2. The lift ring 400 has an inner diameter and an outer diameter. The lift ring 400 includes a plurality of slots 212. The slots 212 are designed to retain the shims 214 shown in FIGS. 4-8. The slots 212 are illustrated as having a circular shape for illustrative purposes only. In practice, the slots 212 may be approximately circular near the outer edge of the lift ring 400 so that the shims 214 can slide in and out of the slots 212. Alternatively, the slots may be completely circular as shown, and the shims 214 may be insertable into the slots 212 and retained therein by retainers 216.

[0083] The number of slots 212 is the same as the number of lift pins 200 used with the substrate support assembly 16. For each slot 212, a portion of the lift ring 400 is removed (cut or gouged) from the lift ring 400 to form a slot 212 with a uniform depth. For example, the slots 212 may be formed by machining or etching a generally circular portion from the top surface of the lift ring 400. The depth of each slot 212 is less than the thickness of the lift ring 400 and is sufficient to allow a shim 214 to be placed within the slot 212. The apex of each slot 212 is flush with the top surface of the lift ring 400. The slots 212 are flush with the lift ring 400.

[0084] The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be embodied in a variety of forms. Accordingly, while the disclosure includes specific embodiments, the true scope of the disclosure should not be so limited, as other variations will become apparent from a study of the drawings, the specification, and the following claims.

[0085] It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure. Furthermore, although each embodiment is described above as having particular features, any one or more of those features described with respect to any embodiment of the present disclosure may be implemented and / or combined with features of any other embodiment, even if that combination is not explicitly stated. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with each other remain within the scope of the present disclosure.

[0086] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless expressly described as "direct," when a relationship between first and second elements is described in the above disclosure, the relationship may be a direct relationship where no other intervening elements exist between the first and second elements, or it may be an indirect relationship where one or more intervening elements exist (spatially or functionally) between the first and second elements.

[0087] As used herein, the phrase at least one of A, B, and C should be construed to mean the logical (A OR B OR C), using a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0088] In some implementations, the controller is part of a system, which may be part of the examples described above. Such systems may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of semiconductor wafers or substrates. This electronics may be referred to as a "controller," which may control various components or subparts of one or more systems.

[0089] The controller may be programmed to control any of the processes disclosed herein, such as supply of process 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, liquid supply settings, position and motion settings, transfer of wafers into and out of tools and other transfer tools and / or load locks connected or interfaced to a particular system, depending on the process requirements and / or type of system.

[0090] Broadly, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software, etc., that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software).

[0091] The program instructions may be instructions communicated to the controller in the form of various personalizations (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. The operational parameters may, in some embodiments, be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or molds of the wafer.

[0092] The controller, in some implementations, may be part of a computer that is integrated with the system, coupled to a computer, coupled to the system, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or in all or part of a fab host computer system that enables remote access of wafer processing. The computer may enable remote access to the system to monitor the current progress of an assembly operation, examine the history of past assembly operations, examine trends or performance results from multiple assembly operations, change parameters of a current process, set up processing steps following the current process, or start a new process.

[0093] In some examples, a remote computer (e.g., a server) can provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows for entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool the controller is configured to interface with or control.

[0094] Thus, as noted above, the controller may be distributed, such as by being comprised of one or more separate controllers networked together that work toward a common purpose, such as the processing and control described herein. An example of a distributed controller for such purposes includes one or more integrated circuits on the chamber that communicate with and couple to one or more remotely located integrated circuits (e.g., at the platform level or as part of a remote computer) to control processing on the chamber.

[0095] Without limitation, exemplary systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0096] As described above, depending on the processing step or steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, other controllers, or tools used in material transport to transport containers of wafers into and out of tool locations and / or load ports within a semiconductor fabrication factory.

Claims

1. an upper end portion having a conical shape that tapers downward; A lower end portion having a cylindrical shape; lift pins for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber, a lift pin holder for holding the lower end of the lift pin; An apparatus comprising:

2. 10. The apparatus of claim 1, a top plate of the substrate support assembly including a downwardly tapered conical bore, the upper ends of the lift pins being suspended from the conical bore when the lift pins are in a lower position; a ring-shaped structure disposed at a base of the substrate support assembly for supporting the lift pin holder and for raising and lowering the semiconductor substrate relative to the top plate; Furthermore, the lift pin holder is suspended above the ring-shaped structure when the lift pins are in the lower position.

3. 3. The apparatus of claim 2, a shim disposed in the slot of the ring-shaped structure, and the lift pin holder is placed on the shim when the ring-shaped structure raises the lift pins to raise the semiconductor substrate from the top plate; a retainer disposed on the shim, surrounding the lift pin holder when the lift pin holder is placed on the shim; and The apparatus further comprises:

4. 10. The apparatus of claim 1, wherein the substrate support assembly includes a top plate having a conical bore that tapers downwardly, the lift pins being suspended from the conical bore with the conical bore supporting the upper ends of the lift pins when the lift pins are in a lowered position.

5. 5. The apparatus of claim 4, wherein in the lower position, the upper ends of the lift pins are suspended from the conical bores at a predetermined distance from an upper surface of the top plate of the substrate support assembly.

6. 10. The apparatus of claim 1, further comprising a ring-shaped structure disposed at a base of the substrate support assembly for supporting the lift pin holder and for raising and lowering the semiconductor substrate relative to the substrate support assembly.

7. 7. The device of claim 6, wherein in the lower position: the upper ends of the lift pins are suspended from downwardly tapering conical bores within a top plate of the substrate support assembly; The lift pin holder, which holds the lower ends of the lift pins, is suspended above the ring-shaped structure.

8. 8. The apparatus of claim 7, further comprising a shim disposed in a slot of the ring-shaped structure, wherein the lift pin holder rests on the shim when the ring-shaped structure raises the lift pins to lift the semiconductor substrate off the top plate.

9. The apparatus of claim 8 further comprising an annular retainer disposed over the shim.

10. 10. The apparatus of claim 9, wherein the annular retainer surrounds a base portion of the lift pin holder when the lift pin holder is placed on the shim.

11. 10. The apparatus of claim 1, wherein the lift pin further comprises a groove adjacent the lower end, and the lift pin holder comprises a ball lock for securing within the groove.

12. 4. The apparatus of claim 3, wherein the lift pins, the lift pin holder, the shim, and the retainer are made from a ceramic material.

13. a plurality of lift pins for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber, each of the lift pins comprising: an upper end portion having a conical shape that tapers downward; A lower end portion having a cylindrical shape; Equipped with a plurality of lift pin holders, each of the lift pin holders holding the lower end of each of the lift pins; a top plate of the substrate support assembly having a plurality of downwardly tapering conical bores, the upper ends of the lift pins being suspended from the conical bores when the lift pins are in a lower position; a ring-shaped structure disposed at a base of the substrate support assembly for supporting the lift pin holder and for raising and lowering the semiconductor substrate relative to the top plate, the lift pin holder being suspended above the ring-shaped structure when the lift pins are in the lower position; A system comprising:

14. 14. The system of claim 13, a plurality of shims respectively disposed within the plurality of slots of the ring-shaped structure; the lift pin holder is placed on each of the shims when the ring-shaped structure raises the lift pins to lift the semiconductor substrate from the top plate; The elevated semiconductor substrate is parallel to the top plate.

15. 15. The system of claim 14, further comprising a plurality of retainers disposed on each of the shims; The retainer surrounds each of the lift pin holders when the lift pin holders are placed on the shims.

16. a first conical portion; and a second portion extending from the first conical portion; a third cylindrical portion having a groove extending from the second portion and inserted into a holder having a ball lock that secures in the groove; A lift pin.

17. a lift pin for raising and lowering a semiconductor substrate relative to a substrate support assembly within a processing chamber, the lift pin comprising: an upper end portion having a conical shape that tapers downward; a lower end portion having a cylindrical shape; a groove adjacent to the lower end; Equipped with a lift pin holder for holding the lower end of the lift pin, the lift pin holder including a ball lock for securing the ball lock within the groove; 1. A lift pin assembly comprising:

18. 20. A system comprising: the lift pin assembly of claim 17; and the substrate support assembly, wherein the substrate support assembly comprises a top plate having a conical bore that tapers downwardly, the lift pins being suspended from the conical bore a predetermined distance from an upper surface of the top plate, with the conical bore supporting the upper ends of the lift pins when the lift pins are in a lower position.

19. 20. A system including the lift pin assembly of claim 17, a top plate of the substrate support assembly including a downwardly tapered conical bore, the upper ends of the lift pins being suspended from the conical bore when the lift pins are in a lower position; a ring-shaped structure disposed at a base of the substrate support assembly for supporting the lift pin holder and for raising and lowering the semiconductor substrate relative to the top plate, the lift pin holder being suspended above the ring-shaped structure when the lift pins are in the lower position; The system further comprises:

20. 20. The system of claim 19, a shim disposed in the slot of the ring-shaped structure and the lift pin holder are placed on the shim when the ring-shaped structure raises the lift pins to lift the semiconductor substrate from the top plate; a retainer disposed on the shim, surrounding the lift pin holder when the lift pin holder is placed on the shim; and The system further comprises:

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