A heater plate comprising a distributed purge channel, an RF mesh, and a ground electrode.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- APPLIED MATERIALS INC
- Filing Date
- 2024-07-09
- Publication Date
- 2026-08-05
Smart Images
Figure 2026526064000001_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present invention generally relate to substrate processing, and more particularly to a heater plate comprising a distributed purge channel, an RF mesh, and a ground electrode.
Background Art
[0002] Producing nanometer and smaller features with high reliability is one of the technical challenges for next-generation very large scale integration (VLSI) and ultra very large scale integration (ULSI) of electronic devices (e.g., semiconductor devices). However, as the limits of circuit technology are pushed, the scaling down of VLSI and ULSI interconnect technology has created additional demands on processing capabilities. Forming gate structures on a substrate with high reliability is important for the success of VLSI and ULSI, as well as for the ongoing efforts to increase the circuit density and quality of individual substrates and dies. To reduce manufacturing costs, integrated chip (IC) manufacturers require higher throughput as well as better device yield and performance each time a substrate is processed. Some substrate processing techniques are carried out at temperatures higher than 300°C.
Summary of the Invention
[0003] In some embodiments, a substrate support assembly is provided. The substrate support assembly includes a heater plate comprising a dielectric material, a heater electrode embedded in the heater plate, a set of distributed purge channels formed within the heater plate that provides a set of gas flow paths for equalizing gas flow from within the heater plate and directing the gas flow in a downward direction of the heater plate, a ground electrode embedded in the heater plate, and a radio frequency (RF) mesh embedded in the plate.
[0004] In some embodiments, a system is provided. The system includes a showerhead assembly, which includes a set of lift pins for receiving a substrate on the showerhead assembly and a showerhead for supplying one or more process gases to perform a deposition process for depositing material on the back side of the substrate. The system further includes a substrate support assembly positioned above the showerhead assembly. The substrate support assembly includes a shaft, a heater plate positioned on the shaft, which includes a heater plate containing a dielectric material, a set of dispersion purge channels formed within the heater plate, which provide a set of gas flow paths for equalizing the gas flow from within the heater plate and directing the gas flow downwards on the heater plate, a ground electrode embedded in the heater plate, and a radio frequency (RF) mesh embedded in the plate.
[0005] In some embodiments, a method is provided. The method comprises obtaining a substrate in a processing chamber and performing a deposition process in the processing chamber using a substrate support assembly to form a material on the substrate by non-contact heating. The substrate support assembly includes a heater plate containing a dielectric material, a heater electrode embedded in the heater plate, a set of dispersion purge channels formed within the heater plate, which provide a set of gas flow paths for equalizing the gas flow from within the heater plate and directing the gas flow downwards toward the heater plate, a ground electrode embedded in the heater plate, and a radio frequency (RF) mesh embedded in the plate.
[0006] Numerous other aspects and features based on these embodiments and other embodiments of the present disclosure are provided. Other features and aspects of the embodiments of the present disclosure will become more fully apparent from the following detailed description, claims and accompanying drawings.
[0007] In the drawings of the accompanying drawings, the embodiments described herein are shown for illustrative purposes only and not for limitation. In the accompanying drawings, similar reference numerals refer to similar elements. Different references to “one” or “single” embodiments in this disclosure do not necessarily refer to the same embodiment, and such references should be understood to mean at least one. [Brief explanation of the drawing]
[0008] [Figure 1] This is a cross-sectional view of an exemplary substrate processing system, including a processing chamber and a substrate support assembly, according to several embodiments. [Figure 2A-2B] This is a cross-sectional view of an exemplary substrate support assembly, including a heater plate comprising a dispersed purge channel, a radio frequency (RF) mesh, and a ground electrode, according to several embodiments. [Figure 2C] This is a top view illustrating an exemplary configuration of a distributed purge channel in a heater plate according to several embodiments. [Figure 2D] This is an exemplary top cross-sectional view of a high-frequency (RF) connector in a substrate support assembly according to several embodiments. [Figure 3A-3B] This is a cross-sectional view of a porous plug that can be included within a dispersed purge channel of a heater plate, according to several embodiments. [Figure 4] This is a flowchart illustrating an exemplary method for manufacturing a substrate support assembly including a heater plate comprising a dispersed purge channel, a radio frequency (RF) mesh, and a ground electrode, according to several embodiments. [Figure 5] This is a flowchart illustrating an exemplary method for processing a substrate in a processing chamber using a substrate support assembly that includes a heater plate comprising a dispersed purge channel, a radio frequency (RF) mesh, and a ground electrode, according to several embodiments. [Modes for carrying out the invention]
[0009] This specification describes embodiments of a heater plate comprising a dispersed purge channel, an RF mesh, and a ground electrode, as well as embodiments for manufacturing the heater plate. Some processing chambers may include a substrate support assembly, which may include a heater plate for heating and / or temperature control during substrate processing. To heat a substrate to a target temperature or temperature range during a manufacturing process such as deposition, etching, and / or lithography, the heater plate may include a set of heater electrodes embedded in the heater plate. The temperature of the heater plate can be controlled by a temperature controller coupled to the set of heater electrodes, which adjusts the power supplied to the set of heater electrodes. The temperature controller may enable precise control of the substrate temperature within a target range for optimizing the manufacturing process underway.
[0010] Purge flow is sometimes used to purge unwanted process gases, such as deposition gases. However, for some processes, such as deposition processes, uniformity of the purge flow onto the substrate can be a challenge. Furthermore, during some deposition processes, such as plasma deposition processes, unwanted material may deposit on the surface of the processing chamber. One example of such a deposition process is back deposition, where material is deposited on the back side of the substrate.
[0011] To address at least the aforementioned drawbacks, embodiments described herein provide a heater plate comprising a dispersed purge channel, an RF mesh, and a ground electrode. For example, a substrate support assembly (e.g., a heater assembly) may include a heater plate positioned on a shaft. The heater plate may be formed from a dielectric material. In some embodiments, the heater plate is a ceramic heater plate formed from a ceramic material. For example, the dielectric material may include aluminum nitride (AlN), aluminum oxide, or alumina (Al2O3).
[0012] A heater plate may include a set of heater electrodes embedded in the heater plate. The heater plate can enable high-temperature operation. In some embodiments, the heater plate enables heating of a substrate to temperatures of 500°C or higher. In some embodiments, the heater plate enables heating to temperatures of 600°C or higher. In some embodiments, the heater plate enables heating to temperatures of 700°C or higher. In some embodiments, the heater plate is a single-zone heater plate. In some embodiments, the heater plate is a multi-zone heater plate. For multi-zone heater plates, the heater plate may be divided into a number of zones, each containing a set of independently controllable heating electrodes or heating electrodes (e.g., resistance heating elements). Thus, different heating may be applied to different zones.
[0013] A substrate support assembly can support the execution of a deposition process from a first side of the substrate by providing a purge flow to a second side of the substrate opposite to the first side. In some embodiments, the first side of the substrate is the back side (e.g., back-side deposition process), and the second side of the substrate is the front side (e.g., front-side purging). For example, a back-side deposition chamber may include a showerhead assembly positioned to face the back side of the substrate and a heater plate facing the front side of the substrate. To form a back-side material (e.g., a film), material can be deposited on the back side of the substrate by any suitable deposition process. For example, the deposition process may be a chemical vapor deposition (CVD) process. In some embodiments, the CVD process is a plasma CVD process (PECVD). A PECVD process refers to a CVD process that uses plasma to generate the reactive species used to deposit the material. For example, the CVD process may be a capacitively coupled plasma (CCP) process. A CCP process can use capacitively coupled plasma to generate reactive species. In a CCP deposition chamber, the substrate is placed between two electrodes, and a high-frequency RF power supply is applied to the electrodes to generate an electric field between the electrodes. The electric field ionizes the process gases in the chamber, and the process gases react with each other to form a material. PECVD processes, such as the CCP process, can be low-temperature processes, which can be beneficial in applications involving materials that may be damaged by high temperatures. In some embodiments, the backing material provides stress compensation and controls the substrate warpage profile caused by processing performed on the front side of the substrate.
[0014] In addition, to prevent defect formation (e.g., scratches or particles), contact between the heater plate and the front surface of the substrate should be minimized. To achieve this, a gap can be provided between the heater plate and the substrate during the deposition process. In some embodiments, the gap is in the range of about 0.5 mm to about 3 mm. To ensure good material quality and stress retention after annealing, the substrate can be heated to a sufficiently high temperature. In some embodiments, the substrate is heated to a temperature in the range of about 450°C to about 650°C. In some embodiments, the substrate is heated to a temperature of about 500°C.
[0015] To prevent material from depositing on the front side of the substrate during the back-side deposition process, the front side of the substrate can be purged to clear away unwanted deposition chemistry. To achieve this, dispersed purge channels can be formed within the heater plate to provide a uniform purge flow through the heater plate. More specifically, dispersed purge channels can be included within the gas pathway of the heater plate, and the shaft can include a set of gas inlets to a purge plenum. A purge plenum is a chamber or enclosure within a gas distribution system that can be used to provide a clean, controlled environment for the purge gas flow. In a purge plenum, the purge gas can be introduced into a chamber separated from the main gas supply pipeline by an airtight barrier. The purge gas flows into the main gas supply pipeline through a series of channels or holes in the barrier, ensuring that the gas is supplied in a controlled and uniform manner. The purge plenum also serves to remove impurities or contaminants from the gas, which helps ensure that the gas has high purity and quality. To ensure a consistent gas flow throughout and to detect leaks or other problems that may occur during operation, monitoring equipment (e.g., sensors) can be installed in the purge plenum.
[0016] In some embodiments, a gas path can be a recurrent gas path. A recurrent gas path is a gas path that branches over multiple levels. For example, a single inlet path (e.g., a source path) can branch into two outlet paths. Each of the two branch paths can then further branch into two additional outlet paths, and so on. By using a recurrent gas path, it is possible to evenly distribute the gas flow from a single inlet (e.g., a source) to multiple outlets (e.g., at least four) and provide good flow uniformity through each of the outlet paths. In some embodiments, the set of gas inlets includes four gas inlets.
[0017] In some embodiments, porous plugs can be formed in each of the purge channels to reduce plasma formation and / or arc generation and prevent damage to the heater plate and / or substrate. For example, porous plugs can prevent ionization of the purge gas by convoluting the gas path and reducing the air volume in the heater plate. The purge flow can allow high pressure to build up on the substrate to prevent plasma ignition and to prevent process gas from diffusing toward the center of the substrate. In some embodiments, the porous plugs are press-fitted into the purge channels. In some embodiments, the porous plugs are fixed within the porous plugs using adhesive. In some embodiments, to fix the porous plugs within the purge channels, the porous plugs have a conical or tapered profile that decreases in diameter toward the substrate.
[0018] When a deposition process such as CCP is used for deposition, the heater plate can serve as an RF-powered electrode. To do so, the heater plate may further include an RF mesh embedded in the heater plate, which can be biased by a symmetric RF supply to improve deposition uniformity. For example, the RF mesh may be positioned toward the upper surface of the heater plate. The RF mesh may include any suitable material according to the embodiments described herein.
[0019] To prevent the accumulation of unwanted material on the processing chamber surface, the heater plate may further include a ground electrode embedded in the heater plate. For example, the ground electrode can protect the processing chamber surface from the potential on the heater plate while driving the electric field and plasma toward the substrate for deposition. The ground electrode may be placed between the set of heater electrodes and the RF mesh.
[0020] The RF mesh and the ground electrode can be connected by an RF connector that passes through the inside of the shaft (for example, the center of the shaft). For example, the RF connector can be an RF coaxial connector that includes an RF feed that can enable symmetric RF supply.
[0021] The heater plate may further include holes for thermocouples to provide temperature feedback. The heater plate may further include edge electrodes. The edge electrodes can enable plasma profile control. Edge electrode pins can be placed between the edge electrodes and the RF mesh. In some embodiments, the edge electrodes are electrically connected to the RF mesh. In some embodiments, the edge electrodes are electrically isolated and energized independently of the RF mesh.
[0022] The embodiments described in this specification can provide numerous advantages. For example, the gap between the substrate and the heater plate can enable non-contact heating of the substrate during processing (e.g., backside deposition process). As another example, a set of distributed purge channels can enable efficient purging of process gases during substrate processing. As yet another example, an RF connector (e.g., RF coaxial) can enable a symmetric RF supply. As yet another example, a ground electrode can prevent unnecessary material from depositing on the processing chamber surface. As yet another example, the use of an RF mesh can enable the heater plate to serve as an RF power electrode during processing (e.g., CCP deposition process). Further details regarding a substrate support assembly including a heater plate having distributed purge channels, an RF mesh, and a ground electrode will be described below with reference to FIGS. 1-5.
[0023] FIG. 1 is a cross-sectional side view of a substrate processing system (“system”) 100 according to some embodiments. As shown, system 100 can include a processing chamber 105 and a substrate support assembly, and the substrate support assembly can include a shaft 110 and a heater plate 120 disposed on shaft 110. More specifically, processing chamber 105 is a deposition chamber that can include a showerhead assembly 130 used to deposit material on substrate 140. Substrate 140 can be placed on a set of lift pins including lift pin 145.
[0024] More specifically, in this exemplary example, system 100 supports a backside deposition process for depositing material on the backside of substrate 140. In some embodiments, this backside deposition process is a plasma deposition process. More specifically, plasma 150 can be generated in the region between showerhead assembly 130 and the backside of substrate 140. In some embodiments, the backside deposition process is a PECVD process. For example, the backside deposition process can be a CCP process.
[0025] The heater plate 120 can heat the substrate 140 during processing (indicated by an arrow directed toward the front side of the substrate 140). The heater plate 120 can be formed from a dielectric material. In some embodiments, the heater plate 120 is formed from a ceramic material. For example, the dielectric material may include AlN, Al2O3, etc. The heater plate 120 may include a set of heater electrodes embedded in the heater plate 120 (not shown in Figure 1). The heater plate 120 can enable high-temperature operation. In some embodiments, the heater plate 120 can be heated to temperatures of 500°C or higher. In some embodiments, the heater plate 120 can be heated to temperatures of 600°C or higher. In some embodiments, the heater plate 120 can be heated to temperatures of 700°C or higher. In some embodiments, the heater plate 120 is a single-zone heater plate. Further details regarding the set of heater electrodes are described below with reference to Figure 2A.
[0026] In some embodiments, a gap 160 is provided between the heater plate 120 and the substrate 140 to prevent defect formation (e.g., scratches or particles) by enabling non-contact heating. In some embodiments, the gap 160 is in the range of about 0.5 mm to about 3 mm. The substrate 140 can be heated to a sufficiently high temperature to ensure sufficiently good material quality and stress retention after annealing. In some embodiments, the substrate 140 is heated to a temperature in the range of about 450°C to about 650°C. In some embodiments, the substrate 140 is heated to a temperature of about 500°C.
[0027] To prevent material from depositing on the front side of the substrate 140 during the back-side deposition process, the front side of the substrate 140 can be purged during processing to remove unwanted deposition chemistry. To achieve this, a purge gas can be supplied through the shaft 110 and released onto the top surface of the substrate 140 through the heater plate 120. For example, a set of dispersed purge channels (not shown in Figure 1) can be formed within the heater plate 120 to provide a uniform purge flow through the heater plate 120. More specifically, the set of dispersed purge channels can provide a set of gas pathways within the heater plate 120. For example, the set of gas pathways can be a set of recurrent gas pathways including a set of gas inlets and a set of gas outlets. In some embodiments, the set of gas inlets includes four gas inlets.
[0028] In addition, the heater plate 120 may include a porous plug (not shown in Figure 1) formed within the purge channel to reduce plasma formation and / or arc generation and prevent damage to the heater plate 120 and / or the substrate 140. For example, the porous plug can prevent ionization of the purge gas by convoluting the gas path and reducing the air volume within the heater plate 120. The purge flow may allow high pressure to build up on the substrate 140 to prevent plasma ignition and to prevent process gas from diffusing toward the center of the substrate 140. In some embodiments, the porous plug is press-fitted into the purge channel. In some embodiments, the porous plug is fixed within the porous plug using adhesive. In some embodiments, to fix the porous plug within the purge channel, the porous plug has a conical or tapered profile that decreases in diameter toward the substrate. Further details regarding the dispersed purge channel and porous plug are described below with reference to Figures 2A to 3B.
[0029] In some embodiments, the heater plate 120 serves as the RF-powered electrode. More specifically, the heater plate 120 may include an RF mesh (not shown in Figure 1) embedded within the heater plate 120, which can be biased by a symmetric RF supply to improve deposition uniformity. For example, the RF mesh may be positioned toward the top surface of the heater plate 120. Further details regarding the RF mesh are described below with reference to Figure 2A.
[0030] In some embodiments, the heater plate 120 may further include a ground electrode (not shown in Figure 1) embedded in the heater plate 120 to prevent the deposition of unwanted material on the surface of the processing chamber 105. For example, the ground electrode can protect the surface of the processing chamber 105 from the potential on the heater plate 120 while the electric field and plasma are driven toward the substrate 140 for deposition. The ground electrode may be placed between the set of heater electrodes and the RF mesh. Further details regarding the ground electrode are described below with reference to Figure 2A.
[0031] The RF mesh and the ground electrode can be connected by an RF connector (not shown in Figure 1) passing through the inside of the shaft 110 (for example, the center of the shaft). For example, the RF connector may be an RF coaxial connector that includes an RF feed that can enable symmetric RF supply. Further details regarding the RF connector are described below with reference to Figures 2A and 2C.
[0032] The heater plate 120 may further include holes (not shown in Figure 1) for thermocouples to provide temperature feedback. The heater plate 120 may further include edge electrodes (not shown in Figure 1). The edge electrodes can enable plasma profile control. Edge electrode pins can be placed between the edge electrodes and the RF mesh. In some embodiments, the edge electrodes are electrically connected to the RF mesh. In some embodiments, the edge electrodes are electrically isolated and powered independently of the RF mesh. Further details of a substrate support assembly including a heater plate comprising a dispersed purge channel, an RF mesh, and a ground electrode are described below with reference to Figures 1 to 4.
[0033] Figure 2A is a cross-sectional view of an exemplary substrate support assembly 200AA according to several embodiments. As shown, the substrate support assembly 200AA may include a shaft 110 and a heater plate 120 disposed on the shaft 110, the shaft 110 and heater plate 120 being similar to the shaft 110 and heater plate 120 described above with reference to Figure 1. For example, the substrate support assembly 200A can be used in the system 100 of Figure 1 during a deposition process (e.g., a back-side deposition process) performed to deposit material onto a substrate (e.g., the back side of the substrate 140 in Figure 1). In some embodiments, the substrate 140 is a circular substrate. For example, the substrate may be a wafer, such as a semiconductor wafer. In some embodiments, the substrate 140 is a non-circular substrate (e.g., a rectangular substrate). For example, the substrate may be a rectangular display or a glass sheet.
[0034] As further shown, the substrate support assembly 200A may include an RF connector 210, a set of heater electrodes including a heater electrode 220 embedded in the heater plate 120, an RF mesh 230 embedded in the heater plate 120, a set of dispersed purge channels 240 including a purge channel 242 formed within the heater plate 120, and a ground electrode 250 embedded in the heater plate 120.
[0035] In some embodiments, the heater plate 120 is capable of heating to a temperature of 500°C or higher. In some embodiments, the heater plate 120 is capable of heating to a temperature of 600°C or higher. In some embodiments, the heater plate 120 is capable of heating to a temperature of 700°C or higher. In some embodiments, the heater plate 120 is a single-zone heater plate.
[0036] As described above with reference to Figure 1, the RF mesh 230 can enable the heater plate 120 to act as an RF-powered electrode. More specifically, the RF mesh 230 can enable biasing the heater plate 120 by a symmetric RF supply to improve deposition uniformity. For example, as shown in Figure 2A, the RF mesh 230 can be placed toward the upper surface of the heater plate 120. The RF mesh 230 can include any suitable material according to the embodiments described herein. In some embodiments, the RF mesh 230 includes molybdenum (Mo). In some embodiments, the RF mesh 230 includes an alloy. For example, the RF mesh 230 can include a suitable iron alloy.
[0037] As described above with reference to Figure 1, a set of dispersed purge channels 240 can be used to purge unwanted deposition chemistry during deposition in order to prevent material from depositing on the first side (e.g., the front side) of the substrate during the deposition process in which material is formed on the second side (e.g., the back side) of the substrate opposite to the first side. In some embodiments, the first side is the front side and the second side is the back side. More specifically, the set of dispersed purge channels 240 can allow for a uniform purge flow through the heater plate 120. More specifically, the set of dispersed purge channels 240 may include a recurrent gas path, and the shaft 110 may include a set of gas inlets to the recurrent purge plenum. In some embodiments, the set of gas inlets includes four gas inlets. In some embodiments, a porous plug is formed within each purge channel of the set of dispersed purge channels 240. The porous plug can be used to reduce plasma formation and / or arc generation to prevent damage to the heater plate 120 and / or the substrate. For example, a porous plug can prevent ionization of the purge gas by convoluting the gas path and reducing the air volume within the heater plate. The purge flow can allow high pressure to build up on the substrate to prevent plasma ignition and to prevent process gases from diffusing toward the center of the substrate. In some embodiments, the porous plug is press-fitted into the purge channel. In some embodiments, the porous plug is fixed within the porous plug using adhesive. In some embodiments, to fix the porous plug within the purge channel, the porous plug has a conical or tapered profile that decreases in diameter toward the substrate. Further details regarding the dispersed purge channel and porous plug are described below with reference to Figures 2C and 3A-3B.
[0038] As described above with reference to Figure 1, a grounding electrode 250 can be used to prevent the deposition of unwanted material on the surface of the processing chamber. For example, the grounding electrode 250 can protect the surface of the processing chamber from the potential on the heater plate 120 while the electric field and plasma are driven toward the substrate for deposition. For example, as shown in Figure 2A, the grounding electrode 250 can be placed between the heater electrode 220 and the RF mesh 230.
[0039] The RF mesh 230 and the ground electrode 250 can be connected by an RF connector 210 that passes through the inside of the shaft 110 (for example, the center of the shaft). For example, the RF connector 210 can be an RF coaxial connector that includes an RF feed that can enable symmetric RF supply. Further details regarding the RF connector are described below with reference to Figure 2C.
[0040] The heater plate 120 may further include holes (not shown in Figure 2A) for thermocouples to provide temperature feedback. In some embodiments, edge electrodes 260 are embedded within the heater plate 120. The edge electrodes 260 can enable plasma profile control. Edge electrode pins (not shown) may be placed between the edge electrodes 260 and the RF mesh 230. In these embodiments, the edge electrodes 260 are electrically connected to the RF mesh 230. In alternative embodiments, the edge electrodes 260 are electrically isolated and powered independently of the RF mesh 230.
[0041] The arrangement of these electrodes embedded in the heater plate 120 should not be considered limiting. In some embodiments, the heater electrode 220 is positioned above the ground electrode 250, as shown in Figure 2A. In other embodiments, the heater electrode 220 is positioned below the ground electrode 250.
[0042] Figure 2B is a cross-sectional view of an exemplary substrate support assembly 200B according to several embodiments. The substrate support assembly 200B is similar to the substrate support assembly 200A, except that it does not include the edge electrodes 260. Furthermore, the RF mesh 230 extends so that its ends are approximately aligned with the ends of electrodes 220 and 250. Further details of the substrate support assembly 200A in Figure 2A and the substrate support assembly 200B in Figure 2B will be described below with reference to Figures 2C–4.
[0043] Figure 2C is a top view of an exemplary configuration of a set of dispersed purge channels 240, including a purge channel 242, according to several embodiments. As further shown in Figure 2C, the set of dispersed purge channels 240 may include a gas inlet ("inlet") including an inlet 244 and a gas outlet ("outlet") including an outlet 246. More specifically, the set of dispersed purge channels 240 may include an inner zone 248-1 and an outer zone 245-2. Purge gas may flow into the substrate support assembly from the gas inlet 244, or be distributed into the substrate support assembly through the purge channel 242, or flow out of the substrate support assembly through the gas outlet 246 toward the substrate located beneath the substrate support assembly. In embodiments, the gas outlets of the inner and outer zones 248-1 and 248-2 allow a constant inert gas flow toward the front side of the substrate during deposition toward the back side of the substrate, preventing deposition toward the front side of the substrate.
[0044] Figure 2D is a top cross-sectional view of an RF connector 210 according to several embodiments. As shown in Figure 2D, the RF connector 210 may include an RF rod 212 and an outer shield 214. The RF rod 212 and the outer shield 214 can be formed from any suitable material. In some embodiments, the RF rod 212 is formed from quartz. In some embodiments, the outer shield 214 is formed from Mo.
[0045] Figure 3A is a cross-sectional view of a portion of a heater plate 300A, including a porous plug 310A formed within a purge channel 242, according to several embodiments. More specifically, the porous plug 310A is a staggered porous plug formed within a staggered purge channel 242 to reduce the direct line of sight between RF and ground. The staggered porous plug has a conical or tapered profile in which the diameter changes as a function of height. The porosity of the porous plug 310A can be selected to suppress plasma formation while allowing heat transfer fluid to reach the substrate support surface. The porous plug 310A can include any suitable material. For example, the porous plug 310A can include a porous dielectric material. The porous plug 310A can be fixed using any suitable bond. For example, the porous plug 310A can be bonded using a high-temperature adhesive (e.g., high-temperature glue).
[0046] Figure 3B is a cross-sectional view of a portion of a heater plate 300B, including a porous plug 310B formed within a purge channel 242, according to several embodiments. More specifically, the purge channel 242 is a counterbore hole, and the porous plug 310B is formed within the counterbore hole. The porous plug 310B can be held in place by an adhesive that fills the vertical gap between the porous plug 310B and the wall of the counterbore hole. The porosity of the porous plug 310B can be selected to suppress plasma formation while allowing the heat transfer fluid to reach the substrate support surface. The porous plug 310B can include any suitable material. For example, the porous plug 310B can include a porous dielectric material. The porous plug 310B can be fixed using any suitable bond. For example, the porous plug 310B can be bonded using a high-temperature adhesive (e.g., high-temperature glue).
[0047] Figure 4 is a flowchart of an exemplary method 400 for manufacturing a heater assembly having a dispersed purge channel, an RF mesh, and a ground electrode, according to several embodiments. For example, method 400 can be performed to manufacture the substrate support assembly 200A shown in Figure 2A.
[0048] In block 410, a heater plate is obtained. The heater plate includes a set of components formed within the plate. The plate can be formed from a dielectric material. In some embodiments, the plate is formed from a ceramic material. For example, the plate can be formed from AlN, Al2O3, etc.
[0049] In some embodiments, obtaining a heater plate includes receiving a pre-formed heater plate. In some embodiments, obtaining a heater plate includes forming at least a portion of a heater plate. For example, forming at least a portion of a heater plate may include embedding heater electrodes in the plate, forming ground electrodes in the heater plate, forming a set of dispersed purge channels in the heater plate, embedding an RF mesh in the heater plate, or embedding edge electrodes in the heater plate.
[0050] In some embodiments, forming a set of dispersed purge channels includes drilling holes in the plate (e.g., laser drilling). In some embodiments, forming a set of dispersed purge channels includes forming at least one porous plug within at least one purge channel of the set of dispersed purge channels. For example, the porous plug may be a staggered porous plug formed within a staggered hole corresponding to a purge channel. As another example, the porous plug may also be formed within a counterbore hole corresponding to a purge channel. The porosity of the porous plug can be selected to suppress plasma formation while allowing heat transfer fluid to reach the substrate support surface. The porous plug may include any suitable material. For example, the porous plug may include a porous dielectric material. The porous plug may be fixed using any suitable bond. For example, the porous plug may be bonded using a high-temperature adhesive (e.g., high-temperature glue).
[0051] In block 420, the heater plate is connected to the shaft. Connecting the heater plate to the shaft may include connecting a set of components to an RF connector. In some embodiments, the RF connector includes an RF coaxial connector that includes an RF feed which can enable symmetric RF supply. For example, the RF coaxial connector may include an RF rod in contact with an RF mesh and an outer shield in contact with a ground electrode. Further details regarding blocks 410-420 are described above with reference to Figures 1-3B.
[0052] Figure 5 is a flowchart of an exemplary method 500 for processing a substrate in a processing chamber using a substrate support assembly including a heater plate comprising a dispersed purge channel, an RF mesh, and a ground electrode, according to several embodiments. For example, method 500 can be performed in system 100 of Figure 1.
[0053] In block 510, the substrate is obtained in the processing chamber. The processing chamber may include a showerhead assembly for supplying process gas into the processing chamber. For example, the processing chamber may be processing chamber 105 in Figure 1, and the substrate may be substrate 140 in Figure 1. Obtaining the substrate may include placing the substrate on a set of lift pins arranged on the showerhead assembly.
[0054] In block 520, a deposition process is performed in a processing chamber using a heater plate to form material on the substrate by non-contact heating. The heater plate can be positioned on a shaft. For example, the heater plate can be the heater plate 120 described above with reference to Figures 1 to 3B. In some embodiments, performing the deposition process includes performing a back deposition process to form material on the back side of the substrate. For example, the back deposition process can be a PECVD process (e.g., a CCP process). Performing the back deposition process may include lowering the heater plate toward the front side of the substrate to provide a gap between the heater plate and the front side of the substrate, and initiating the back deposition process. The gap allows for non-contact heating of the substrate using a set of heater electrodes on the heater plate. The deposition process can be performed by generating plasma in the region between the back side of the substrate and the showerhead assembly. Unwanted process gases can be purged from the front side of the substrate using a set of dispersed purge channels formed within the heater plate. The heater plate may further include a ground electrode to prevent plasma ignition near the shaft and to protect the set of heater electrodes from RF, and an RF mesh to enable biasing capability. RF connectors (e.g., RF coaxial connectors) formed through the shaft to the heater plate can enable symmetric RF supply. In some embodiments, the heater plate further includes edge electrodes for plasma profile control. Further details regarding blocks 510-520 are described above with reference to Figures 1-4.
[0055] To provide a thorough understanding of some embodiments of the present invention, the above description includes numerous specific details, such as examples of particular systems, components, and methods. However, it will be apparent to those skilled in the art that at least some embodiments of the present invention can be carried out without these specific details. As another example, to avoid unnecessarily obscuring the invention, well-known components or methods are not described in detail or are shown in the form of simple block diagrams. Thus, the specific details described are merely examples. Certain embodiments may differ from these exemplary details, yet they are still intended to be included within the scope of the present invention.
[0056] Throughout this specification, any reference to “one embodiment” or “one embodiment” means that the specific features, structure, or characteristics described in relation to that embodiment are included in at least one embodiment. Therefore, the occurrence of the phrase “in one embodiment” or “in one embodiment” in various places throughout this specification does not necessarily all refer to the same embodiment. In addition, the term “or” is intended to mean inclusive “or” rather than exclusive “or.” Where the term “about” or “approximately” is used in this specification, it is intended to mean that the presented nominal values are accurate within a range of ±25%.
[0057] The operations of the methods described herein are shown and described in a specific order, but the order of operations of each method may be changed so that some operations are performed in reverse order, or so that some operations are performed at least partially concurrently with others. In another embodiment, instructions or suboperations of different operations may be performed intermittently and / or alternately.
[0058] It should be understood that the above description is intended to be illustrative and not limiting. Many other embodiments will be obvious to those skilled in the art who have read and understood the above description. Accordingly, the scope of the invention should be determined in terms of the full scope of the appended claims and the equivalent works to which such claims are granted.
Claims
1. A heater plate containing a dielectric material, The heater electrode embedded in the heater plate, A set of dispersed purge channels formed within the heater plate, which provides a set of gas flow paths for equalizing the gas flow from within the heater plate and directing the gas flow downwards toward the heater plate, The ground electrode embedded in the heater plate, The high-frequency (RF) mesh embedded in the heater plate and A substrate support assembly comprising:
2. The substrate support assembly according to claim 1, wherein the dielectric material is a ceramic material.
3. The substrate support assembly according to claim 1, further comprising a shaft, wherein the heater plate is disposed on the shaft.
4. The substrate support assembly according to claim 3, further comprising an RF connector formed in the shaft, wherein the RF connector is coupled to the heater plate.
5. The substrate support assembly according to claim 4, wherein the RF connector is an RF coaxial connector comprising an outer shield and an RF rod.
6. The substrate support assembly according to claim 1, further comprising porous plugs disposed within the purge channels of the set of dispersed purge channels.
7. The substrate support assembly according to claim 1, further comprising an edge electrode embedded in the heater plate.
8. A shower head assembly comprising a set of lift pins for receiving a substrate on the shower head assembly, and a shower head for supplying one or more process gases to perform a deposition process for depositing material on the back side of the substrate, A substrate support assembly positioned above the shower head assembly and The substrate support assembly comprises, The shaft and A heater plate disposed on the shaft, comprising a dielectric material, The heater electrode embedded in the heater plate, A set of dispersed purge channels formed within the heater plate, which provides a set of gas flow paths for equalizing the gas flow from within the heater plate and directing the gas flow downwards toward the heater plate, The ground electrode embedded in the heater plate, The high-frequency (RF) mesh embedded in the heater plate and A system equipped with these features.
9. The system according to claim 8, wherein the dielectric material is a ceramic material.
10. The system according to claim 8, wherein the substrate support assembly further comprises an RF connector formed in the shaft, and the RF connector is coupled to the heater plate.
11. The system according to claim 10, wherein the RF connector is an RF coaxial connector comprising an outer shield and an RF rod.
12. The system according to claim 8, wherein the substrate support assembly further comprises porous plugs disposed within the purge channels of the set of dispersed purge channels.
13. The system according to claim 8, wherein the substrate support assembly further comprises edge electrodes embedded in the heater plate.
14. The system according to claim 8, wherein the deposition process is a capacitively coupled plasma (CCP) deposition process.
15. To obtain a substrate in the processing chamber, Using a substrate support assembly, the deposition process is performed in the processing chamber to form a material on the substrate by non-contact heating. The substrate support assembly includes, A heater plate containing a dielectric material, The heater electrode embedded in the heater plate, A set of dispersed purge channels formed within the heater plate, which provides a set of gas flow paths for equalizing the gas flow from within the heater plate and directing the gas flow downwards toward the heater plate, The ground electrode embedded in the heater plate, The high-frequency (RF) mesh embedded in the heater plate and A method that includes [a certain feature].
16. The method according to claim 15, wherein obtaining the substrate includes placing the substrate on a set of lift pins arranged on the shower head assembly of the processing chamber.
17. The method according to claim 15, wherein the deposition process is a capacitively coupled plasma (CCP) deposition process.
18. The method according to claim 15, wherein the deposition process is a back deposition process in which the material is formed on the back side of the substrate.
19. Performing the aforementioned deposition process The heater plate is lowered toward the front side of the substrate, providing a gap between the heater plate and the front side of the substrate. To initiate the aforementioned backside deposition process The method according to claim 18, including the method described in claim 18.
20. The method according to claim 15, wherein the substrate support assembly further comprises edge electrodes embedded in the plate.