JP2018110221A - Chemical evaporation chamber for gas seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical evaporation chamber having a showerhead module thermally isolated from its surrounding component for achieving uniform temperature of a whole substrate.SOLUTION: A chemical evaporation chamber 100 comprises a showerhead module 130 having a faceplate 136 provided with a gas inflow port for supplying a reactor chemical substance to a wafer cavity 150 for processing a semiconductor substrate 190. An inert gas supply part supplies seal gas inwardly flowing in a radial direction at least partially via a gap between a step of the showerhead module 130 and a pedestal module 140 for forming a gas seal.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an apparatus and process for performing chemical vapor deposition and plasma enhanced chemical vapor deposition.

  Etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), pulse deposition layer (PDL), plasma enhanced pulse deposition layer A plasma processing apparatus can be used to process a semiconductor substrate by techniques such as (PEPDL) processing and resist removal. For example, one type of plasma processing apparatus used for plasma processing includes a reaction chamber or deposition chamber that houses upper and lower electrodes. Radio frequency (RF) power is applied between the electrodes to excite the process gas to a plasma state and process the semiconductor substrate in the reaction chamber.

  According to one embodiment, a chemical vapor deposition chamber having a gas seal includes a showerhead module and a pedestal module configured to support a semiconductor substrate within a wafer cavity under a faceplate. The faceplate includes a plurality of gas inlets configured to supply process gas to the wafer cavity. The showerhead module includes a primary exhaust outlet configured to remove reactive gas chemicals and inert gases from the wafer cavity. The showerhead module includes a stage at the outer periphery of the wafer cavity and an inert gas supply configured to supply an inert gas to form a gas seal in the gap between the stage and the pedestal module. The showerhead module includes a secondary exhaust outlet disposed radially outward of the main exhaust outlet, the secondary exhaust outlet removing at least a portion of the inert gas flowing radially inward through the gap. It is configured as follows.

  According to another embodiment, a method for confining a reactive gas chemical to prevent leakage from a wafer cavity of a chemical vapor deposition chamber described above comprises the following steps: (a) supporting a semiconductor substrate on a pedestal module (B) flowing process gas through the gas inlet of the faceplate; (c) drawing gas from the wafer cavity through the primary exhaust outlet; and (d) inert gas through the inert gas supply. Maintaining a gas seal in the gap between the step and the pedestal module by flowing a gas; (e) at least a portion of the inert gas flowing radially inward through the secondary exhaust outlet Drawing out.

1 is a schematic diagram illustrating a chemical vapor deposition apparatus with a pedestal, according to a representative embodiment. FIG.

1 is a schematic diagram illustrating a chemical vapor deposition apparatus that does not include a pedestal, according to a representative embodiment. FIG.

1 is a cross-sectional view illustrating a gas-based sealing system in accordance with an exemplary embodiment.

1 is a cross-sectional view illustrating a gas-based sealing system in accordance with an exemplary embodiment.

1 is a cross-sectional view illustrating a gas-based sealing system in accordance with an exemplary embodiment.

1 is a cross-sectional view illustrating a gas-based sealing system in accordance with an exemplary embodiment.

1 is a cross-sectional view illustrating a gas-based sealing system in accordance with an exemplary embodiment.

1 is a schematic diagram illustrating a gas-based sealing system, according to a representative embodiment. FIG.

6 is a graph showing pressure and valve angle-time for a gas-based sealing system, according to an exemplary embodiment.

The figure which shows the gas flow in the shower head module which has a seal gas structure and the main exhaust outlet which exists in the outer periphery of a faceplate.

FIG. 6 illustrates gas flow in a showerhead module having a gas seal configuration, a main exhaust outlet on the outer periphery of the faceplate, and a secondary exhaust outlet outside the main exhaust outlet and inside the seal gas inlet. Figure.

The figure which shows the flow of gas about the shower head module which has a main exhaust outlet and a secondary exhaust outlet.

The figure which shows the shower head module which has the two-piece isolation ring which provided the sealing gas outflow port in the lower surface of the inner ring, and provided the secondary exhaust outlet in the inner surface of the inner ring.

The figure which shows a mode that an inner side ring fits around the face plate and backing plate of a shower head module.

The figure which shows the gas connection connected to the secondary exhaust passage in the upper plate of a shower head module.

  In the following detailed disclosure, exemplary embodiments are described to provide an understanding of the devices and methods disclosed herein. However, it will be apparent to those skilled in the art that the exemplary embodiments may be practiced without these specific details, or may be practiced with other elements or processes. In other instances, well-known processes, procedures, and / or components have not been described in detail so as not to unnecessarily obscure aspects of the embodiments disclosed herein.

  According to exemplary embodiments, the apparatus and related methods disclosed herein can be utilized for chemical vapor deposition, such as plasma enhanced chemical vapor deposition. The apparatus and method are self-contained in a multi-step deposition process (eg, atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), pulsed deposition layer (PDL), or plasma enhanced pulse deposition layer (PEPDL) process). It can be used with, but not limited to, semiconductor processing-based dielectric deposition processes that require limited deposition separation.

  As described above, the present embodiment provides an apparatus and related methods for performing chemical vapor deposition, such as plasma enhanced chemical vapor deposition. The apparatus and method include multi-step deposition processes (eg, atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), plasma enhanced chemical vapor deposition (PECVD), pulsed deposition layer (PDL), plasma enhanced pulse deposition layer ( It is particularly applicable to, but not limited to, combined use with semiconductor processing-based dielectric deposition processes that require separation of self-limiting deposition processes in PEPDL) processes).

  The above process can have several drawbacks associated with non-uniform temperatures across the wafer or substrate that receives the deposition material. For example, a non-uniform temperature can occur across the substrate when a passively heated showerhead that is in thermal contact with the surrounding chamber components is deprived of heat by the surrounding components. Therefore, the shower head that forms the upper wall of the processing region is preferably thermally isolated from the surrounding components so that a uniform temperature of the entire substrate can be achieved by forming an isothermal processing region. . The uniform temperature across the substrate helps the uniform processing of the substrate, and the substrate temperature is a control means that drives the deposition reaction to provide activation energy for the deposition process.

  In addition, there are generally two main types of vapor deposition showerheads, a chandelier type and a buried type. The chandelier-type shower head has a stem attached to the upper part of the chamber at one end and a face plate at the other end, and looks like a chandelier. A portion of the stem may protrude from the top of the chamber to allow connection of gas lines and RF power. The embedded shower head is integrated in the upper part of the chamber and does not have a stem. This embodiment relates to an embedded showerhead, which reduces the chamber space that needs to be evacuated by a vacuum source during processing.

  1A and 1B are schematic diagrams illustrating a chemical vapor deposition apparatus 100 according to an embodiment disclosed herein. As shown in FIGS. 1A and 1B, the chemical apparatus includes a chemical isolation chamber or housing 110, a deposition chamber 120, a showerhead module 130, and a moving pedestal module 140, and the pedestal module 140 is a pedestal module 140. In order to move the position of the substrate (or wafer) 190 on the upper surface of the shower head module 130 up and down, it can be moved vertically up and down with respect to the shower head module 130. The shower head module 130 can also be moved up and down vertically. Reactant gas (ie, process gas) 192 (FIG. 3) is introduced into subchamber (ie, wafer cavity) 150 through central plenum 202 (FIG. 6) of showerhead module 130 via gas line 112. Each of the gas lines 112 may have a corresponding accumulator (not shown), which can be isolated from the apparatus 100 using an isolation valve (not shown). According to an exemplary embodiment, the apparatus 100 can be modified to have one or more gas lines 112 with isolation valves and accumulators, depending on the number of reactant gases utilized. In addition, the reactive gas supply line 112 can be shared among a plurality of chemical vapor deposition apparatuses or between multi-station systems.

  According to an exemplary embodiment, chamber 120 may be evacuated through one or more vacuum lines 160 (FIG. 2) connected to a vacuum source (not shown). For example, the vacuum source may be a vacuum pump (not shown). In a multi-station reactor (eg, a reactor having multiple stations or apparatus 100 performing the same deposition process), a vacuum line 160 from another station may share a common foreline with the vacuum line 160. Further, the device 100 may be modified to have one or more vacuum lines 160 per station or device 100.

  According to an exemplary embodiment, a plurality of exhaust conduits 170 may be configured to be in fluid communication with one or more exhaust outlets 174 in the faceplate 136 of the showerhead module 130. The exhaust outlet 174 may be configured to remove process gas or reactor chemical 192 from the wafer cavity 150 between deposition processes. The plurality of exhaust conduits 170 are also in fluid communication with one or more vacuum lines 160. The exhaust conduits 170 may be circumferentially spaced around the substrate 190 and may be evenly spaced. In some examples, the spacing between the plurality of conduits 170 may be designed to compensate for the position of the vacuum line 160. In general, since the vacuum line 160 is fewer in number than the plurality of conduits 170, the flow rate through the conduit 170 closest to the vacuum line 160 can be higher than the more distant conduits. In order to ensure a smooth flow pattern, the distance between the conduits 170 may be closer to the vacuum line 160. An exemplary embodiment of a chemical vapor deposition apparatus 100 with a plurality of conduits 170 with variable flow conductors can be found in commonly assigned US Pat. No. 7,993,457, which is incorporated herein by reference. Is incorporated herein in its entirety.

  The embodiments disclosed herein are preferably implemented in a plasma enhanced chemical vapor deposition apparatus (eg, a PECVD apparatus, a PEALD apparatus, or a PEPDL apparatus). Such an apparatus may take various forms, and the apparatus may include one or more chambers or “reactors” 110 that contain one or more substrates 190 and are suitable for substrate processing, the chambers described above. A plurality of stations or deposition chambers 120 may be included. Each chamber 120 may contain one or more substrates for processing. One or more chambers 120 maintain the substrate 190 in one or more predetermined positions (eg, there may or may not be movement within that position, such as rotation, vibration, or other movement). . In one embodiment, a substrate 190 undergoing deposition and processing may be transferred from one station (eg, deposition chamber 120) within apparatus 100 to another station during processing. During processing, each substrate 190 is held in place by a pedestal of the pedestal module 140, a wafer chuck, and / or other wafer holding devices. For certain operations in which the substrate 190 is heated, the pedestal module 140 may include a heater, such as a heating plate.

  FIG. 2 is a cross-sectional view illustrating a chemical vapor deposition apparatus 100 having a gas-based sealing system 200 in accordance with a representative embodiment. As shown in FIG. 2, the chemical vapor deposition apparatus 100 includes a substrate pedestal module 140, which receives a semiconductor substrate (or wafer) and / or from the upper surface 142 of the pedestal module 140 to the substrate 190. Is configured to take down. In the lower position, the substrate 190 is placed on the surface 142 of the pedestal module 140, after which the pedestal module 140 is lifted vertically upward toward the showerhead module 130. According to an exemplary embodiment, the distance between the upper surface 142 of the pedestal module 140 and the lower surface 132 of the showerhead module 130 forms a wafer cavity 150 and is about 0.2 inches (5 millimeters) to about 0. .6 inches (15 millimeters). The upward vertical motion of the pedestal module 140 to close the wafer cavity 150 is between the pedestal module 140 and the step 135 around the outer portion 131 of the faceplate 136 (FIGS. 1A and 1B) of the showerhead module 130. Create a narrow gap 240.

  In an exemplary embodiment, the temperature in the chamber 120 can be maintained by a heating mechanism in the showerhead module 130 and / or the pedestal module 140. For example, the substrate 190 can be placed in an isothermal environment, and the showerhead module 130 and the pedestal module 140 are configured to maintain the substrate 190 at a desired temperature. In an exemplary embodiment, the showerhead module 130 can be heated to a temperature greater than 250 ° C. and / or the pedestal module 140 can be heated to a range of 50 ° C. to 550 ° C. The deposition chamber or cavity 150 functions to contain a plasma generated by a capacitively coupled plasma type system with a showerhead module 130 in conjunction with a pedestal module 140.

  One or more RF sources (not shown), such as a high frequency (HF) RF generator and a low frequency (LF) RF generator connected to a matching network (not shown), are provided to the showerhead module 130. It is connected. The power and frequency supplied by the matching network is sufficient to generate a plasma from the process gas / vapor. In one embodiment, both an HF generator and an LF generator can be used. In a typical process, the HF generator is generally operated at a frequency of about 2-100 MHz, and in a preferred embodiment is operated at 13.56 MHz. The LF generator is generally operated at about 50 kHz to 2 MHz, and in the preferred embodiment is operated at 350-600 kHz. Process parameters may be increased or decreased based on chamber volume, substrate size, and other factors. For example, the power output of the LF generator and the HF generator is typically directly proportional to the deposition surface area of the substrate. The power used for a 300 mm wafer is generally at least 2.25 higher than the power used for a 200 mm wafer. Similarly, the flow rate (eg, standard vapor pressure, etc.) can depend on the free capacity of the deposition chamber 120.

  Within the deposition chamber 120, the pedestal module 140 supports a substrate 190 on which material can be deposited. The pedestal module 140 typically includes a chuck, fork, or lift pin to hold and transport the substrate during and between the deposition and / or plasma processing reactions. The pedestal module 140 may comprise an antistatic chuck, a mechanical chuck, or various other types of chucks available for industry and / or research. The pedestal module 140 may be combined with a heater block for heating the substrate 190 to a desired temperature. In general, the substrate 190 is maintained at a temperature of about 25 ° C. to 500 ° C., depending on the material being deposited.

  According to an exemplary embodiment, the gas-based sealing system 200 can be configured to help control and regulate the flow exiting the wafer cavity 150 during the flow of process material or purge gas. According to an exemplary embodiment, evacuation or purging of the wafer cavity 150 utilizes an inert gas or purge gas (not shown), which is supplied to the wafer cavity 150 through the showerhead module 130. According to an exemplary embodiment, one or more conduits 170 may be connected to the vacuum line 160 via an annular exhaust passage 176 that passes from an area below the pedestal module 140 to an inert seal gas. 182 (FIG. 2) is configured to be removed.

  According to an exemplary embodiment, showerhead module 130 is configured to supply reactor chemistry to wafer cavity (ie, reaction chamber) 150. The shower head module 130 may include a face plate 136 having a plurality of inlets or through holes 138, and a backing plate 139. According to an exemplary embodiment, the faceplate 136 may be a single plate having a plurality of inlets or through holes 138 and a step 135 extending around the outer periphery 137 of the faceplate 136. Alternatively, the step 135 may be a separate ring 133 and is secured to the lower surface of the outer portion 131 of the face plate 136. For example, the step 135 can be secured to the outer portion 131 of the face plate 136 with screws 143. A representative embodiment of a process gas dispersion showerhead module 130 with a faceplate 136 having a concentric exhaust outlet 174 can be found in commonly assigned US Pat. No. 5,614,026. That patent is incorporated herein by reference in its entirety. For example, according to an exemplary embodiment, the exhaust outlet 174 surrounds the plurality of inlets 138.

  According to an exemplary embodiment, the wafer cavity 150 is formed between the lower surface 132 of the face plate 136 of the showerhead module 130 and the upper surface 142 of the substrate pedestal module 140. A plurality of concentric exhaust conduits or exhaust outlets 174 in the faceplate 136 of the showerhead module 130 provide a plurality of conduits 170 for removing process gas or reactor chemistry 192 from the wafer cavity 150 between deposition processes. May be in fluid communication with one or more.

  As shown in FIG. 2, the apparatus 100 further includes a source 180 of inert or sealing gas 182 that is passed through one or more conduits 184 to the outer plenum of the gas-based sealing system 200. 204. According to an exemplary embodiment, the inert gas or seal gas 182 may be nitrogen gas or argon gas. According to an exemplary embodiment, the inert gas source 180 is configured to supply an inert seal gas 182 for flowing radially inward through the narrow gap 240 via one or more conduits 184. The gap 240 extends outward from the wafer cavity 150 and is formed between the lower surface 134 of the step 135 around the outer periphery 137 of the face plate 136 and the upper surface 142 of the pedestal module 140. According to an exemplary embodiment, the inert seal gas 182 contacts the process gas or reactor chemistry 192 (FIG. 3) from the wafer cavity 150 in the narrow gap 240 to form a gas seal during processing. As shown in FIGS. 3 and 4, the inert seal gas 182 enters only part of the narrow gap 240, thereby providing a gas seal between the reactor chemical 192 and the inert gas 182 within the narrow gap. It is formed. Alternatively, as shown in FIGS. 5 and 6, the flow of inert gas 182 reaches the outer edge of wafer cavity 150 and is removed from wafer cavity 150 through one or more exhaust outlets 174 in showerhead module 130. Also good.

  According to an exemplary embodiment, the annular exhaust passage 176 is in fluid communication with one or more of the plurality of exhaust conduits 170. According to an exemplary embodiment, the annular exhaust passage 176 has one or more outlets (not shown) and passes through an inert gas 182 from a region surrounding the periphery of the substrate 190 and a narrow gap 240. It is configured to remove the inert gas 182 that moves or flows radially inward. The exhaust passage 176 is formed in the outer portion 144 of the substrate base 140. The annular exhaust passage 176 may be configured to remove the inert gas 182 from under the substrate pedestal 140. Further embodiments with multiple conduits similar to 176 allow more inert gas 182 to be drawn in, increasing the flow of inert gas to the exhaust passage 178 and the lower portion of the pedestal module 140. Can be helpful. The exhaust passage 178 can also help increase the pressure drop of the seal gas and reduce the diffusion of the seal gas into the wafer cavity 150.

  FIG. 3 is a cross-sectional view illustrating a portion of a deposition chamber 120 of a chemical vapor deposition apparatus 100 having a gas-based sealing system 200 in accordance with an exemplary embodiment. As shown in FIG. 3, the outer plenum 204 may be formed on the outer portion 131 of the face plate 136. The outer plenum 204 may include one or more conduits 220 that are configured to receive the inert gas 182 from the inert gas source 180. Inert gas 182 flows through outer plenum 204 through one or more conduits 220 to lower outlet 228. Lower outlet 228 is in fluid communication with narrow gap 240. According to an exemplary embodiment, the distance from the outer edge 152 of the wafer cavity 150 to the outer periphery 141 of the faceplate 136 leading to the outer plenum 204 is a finitely controlled distance. For example, the distance (ie, width) from the outer edge 152 of the cavity 150 to the outer edge 141 of the faceplate 136 leading to the outer plenum 204 may be about 5.0 mm to 25.0 mm.

According to an exemplary embodiment, the outer plenum 204 may be an outer annular recess 222.
The outer annular recess 222 is configured to be in fluid communication with a narrow gap 240 on the outer edge of the wafer cavity 150 via one or more conduits 220. The outer annular recess 222 may be configured to have an upper annular recess 224 and a lower annular recess 226, and the upper annular recess 224 has a wider width than the lower annular recess 226. According to an exemplary embodiment, the lower outlet 228 is an annular outlet in the lower portion of the lower annular recess 226 and is in fluid communication with the narrow gap 240.

  According to an exemplary embodiment, as shown in FIG. 3, inert gas 182 is supplied through outer plenum 204 to the outer edge of wafer cavity 150 spaced a finitely controlled distance. The flow rate of the inert gas 182 flowing through the outer plenum 204 may be such that the Peclet number is greater than about 1.0, so that the reactor gas chemical 192 is contained within the wafer cavity 150 as shown in FIG. Be trapped. For example, if the Peclet number is greater than 1.0, the inert gas 182 and the reactor gas chemical 192 may establish an equilibrium within the inner portion 242 of the narrow gap 240. As a result, the reactor gas chemical 192 can be prevented from flowing under the substrate pedestal module 140 and contaminating the portion of the deposition chamber 120 outside the wafer cavity 150.

  According to an exemplary embodiment, when the process is a constant pressure process, an inert gas seal between the reactor gas chemistry 192 in the wafer cavity 150 and the inert gas 180 that flows radially inward through the narrow gap 240 is provided. A combination of a single (or constant) flow of inert gas 182 and pressure from below the pedestal module 140 may be sufficient to ensure. For example, according to an exemplary embodiment, the gas-based sealing system 200 can be utilized with Si ALD oxide and can generally be operated in a relatively constant pressure mode. Further, the gas-based sealing system 200 can vary the flow rate of the inert gas 182 or the pressure under the pedestal module 140 and / or a combination of both, for example, during the ALD nitride process, the deposition chamber 120 and It can serve as a means to control gas sealing over various processes and pressure regimes within the wafer cavity 150.

  According to an exemplary embodiment, the sealing gas system 200 disclosed alone or with pressure with respect to the exhaust conduits 174, 176 may cause the reactor chemical 192 outflow from the wafer cavity 150 and / or during processing. Can help prevent diffusion. Further, the system 200 may also prevent bulk flow of inert gas 182 into the wafer cavity 150 and onto the substrate 190, either alone or in combination with pressure on the exhaust conduits 174, 176 and exhaust conduits 174, 176. The flow rate of inert gas 182 into the narrow gap 240 to isolate the wafer cavity 150 can be adjusted based on the pressure generated by the exhaust outlet 174. According to an exemplary embodiment, for example, an inert gas or seal gas 182 may be supplied through the outer plenum 204 at a flow rate between about 100 cc / min and about 5.0 standard liters per minute (slm), and causes the wafer cavity 150 to pass through. Available to isolate.

  According to an exemplary embodiment, one or more exhaust cavities 250 may be disposed on the outer portion of the pedestal module 140 surrounding the wafer cavity 150. One or more exhaust cavities 250 can be in fluid communication with the narrow gap 240 and the lower outlet 228 to increase the pressure drop from the wafer cavity 150 to the inert gas or gas supply 180. The one or more exhaust cavities 250 (ie, annular channels) can also provide additional control mechanisms to allow gas sealing across various processes and pressure regimes, for example, during ALD nitride processing. According to an exemplary embodiment, the one or more exhaust cavities 250 may be evenly spaced around the deposition chamber 120. In the exemplary embodiment, the one or more exhaust cavities 250 may be annular channels, are concentric with the lower outlet 228, and have a wider width.

  FIG. 4 is a cross-sectional view illustrating a part of the deposition chamber 120 of the chemical vapor deposition apparatus 100 including the gas-based sealing system 200. As shown in FIG. 4, if the flow rate of the reactor chemical 192 is greater than or approximately equal to the flow rate of the inert gas 182, the flow of the reactor chemical 192 can spread outside the wafer cavity 150, and is therefore undesirable. There is.

  As shown in FIG. 4, an annular exhaust passage 176 provides a secondary exhaust passage in addition to the main exhaust passage 174 in the face plate 136. The annular exhaust passage 176 is configured to remove the inert gas 182 from under the substrate pedestal 140 and from a region surrounding the periphery of the substrate 190. According to an exemplary embodiment, the annular exhaust passage 176 has one or more outlets (not shown) and passes through an inert gas 182 from a region surrounding the periphery of the substrate 190 and a narrow gap 240. It is configured to remove the inert gas 182 that flows radially inward, that is, diffuses.

  FIG. 5 is a cross-sectional view illustrating a portion of a deposition chamber 120 of a chemical vapor deposition apparatus 100 with a gas-based sealing system 200 in accordance with a representative embodiment. The flow of inert gas 182 from outside the cavity 150 may be caused by reducing the flow rate of the reactor chemical 192 and / or increasing the flow rate of the inert gas 182. According to an exemplary embodiment, the inert gas 182 from the outer plenum 204 may flow into the wafer cavity 150 and be removed through one or more exhaust outlets 174 in the showerhead module 130.

  FIG. 6 is a cross-sectional view illustrating a portion of a deposition chamber 120 of a chemical vapor deposition apparatus 100 with a gas-based sealing system 300 according to a representative embodiment. According to an exemplary embodiment, the central plenum 202 of the showerhead module 130 includes a plurality of inlets or through holes 138 that supply the reactor chemistry 192 to the wafer cavity 150. Wafer cavity 150 further includes a concentric conduit or exhaust outlet 174 that removes reactor chemistry 192 and inert gas 182 from wafer cavity 150. A concentric conduit or exhaust outlet 174 may be in fluid communication with the intermediate plenum 208 between the backing plate 139 and the upper plate 310. The intermediate plenum 208 is in fluid communication with one or more of the plurality of exhaust conduits 170.

  The showerhead module 130 may further include a vertical gas passage 370 that is configured to supply an inert gas 182 around the outer periphery 137 of the faceplate 136. According to an exemplary embodiment, an outer plenum 206 may be formed between the outer periphery 137 of the face plate 136 and the inner periphery or inner edge 212 of the isolation ring 214.

  As shown in FIG. 6, the system 300 includes a vertical gas passage 370 formed in the inner flow path 360 in the upper plate 310 and in the outer portion 320 of the backing plate 139. The vertical gas passage 370 may include one or more conduits 312, 322 that are configured to receive the inert gas 182 from an inert gas source or supply 180. According to an exemplary embodiment, the inert gas 182 passes through the upper plate 310 and the outer portion 320 of the backing plate 139 by one or more conduits 312, 322 and one or more recesses and / or channels 330. 340, 350 to the outer edge of the wafer cavity 150.

  According to an exemplary embodiment, the one or more conduits 312 may include an upper annular recess 314 and a lower outer annular recess 316. According to an exemplary embodiment, the upper recess 314 is wider than the lower recess 316. Further, one or more conduits 322 can be disposed within the upper portion 310 and the outer portion 320 of the backing plate 139. The one or more conduits 322 may form an annular recess having an inlet 326 in fluid communication with the outlet 318 of the upper plate 310 and an outlet 328 in fluid communication with the narrow gap 240. According to an exemplary embodiment, the outlet 328 in the outer portion 320 has one or more that guides the flow of inert gas 182 around the outer periphery of the faceplate 136 of the showerhead module 130 to the outer edge 243 of the narrow gap 240. In recesses and / or flow paths 330, 340, 350.

  In accordance with the exemplary embodiment, inert gas 182 is supplied to outer plenum 206 through vertical gas passage 370 and toward wafer cavity 150 through a narrow gap 240 that is at least partially radially inward. The flow rate of the inert gas 182 flowing through the one or more recesses and / or flow paths 330, 340, 350 may be such that the Peclet number is greater than 1.0 and thus reacts within the wafer cavity 150. A gas chemical 192 is trapped. According to an exemplary embodiment, when the Peclet number is greater than 1.0, the inert gas 182 and the reactive gas chemical 192 establish an equilibrium within the inner portion 242 of the narrow gap 240, and thus the reactive gas chemical. It is prevented that 192 flows under the pedestal module 140 and contaminates the portion of the deposition chamber 120 outside the wafer cavity 150. According to an exemplary embodiment, by confining the flow of reactive gas chemical 192 in the wafer cavity 150, the system 200 can reduce the amount of process gas 192 usage. In addition, the system 200 can reduce the filling time of the wafer cavity 150 with the process gas 192 during processing.

  FIG. 7 is a schematic diagram illustrating a gas-based sealing system 400 in accordance with an exemplary embodiment. As shown in FIG. 7, system 400 includes an inert gas or seal gas source 180 and a process gas source 19, which are inert gas or seal gas 182 and process gas, respectively. A gas 192 is configured to be supplied to the wafer cavity 150. The system 400 may further comprise a wafer cavity pressure or cavity pressure valve 410 and a lower chamber pressure valve 412 that control the wafer cavity pressure or cavity pressure 414 and the lower chamber pressure 416, respectively.

  FIG. 8 is a graph 500 illustrating pressure and valve angle-time for a gas-based sealing system 400, according to a representative embodiment. According to an exemplary embodiment, process gas 192 in the form of helium is supplied to wafer cavity 150 at a flow rate between 0 and about 20 SLM (standard liters per minute), as shown in FIG. An inert gas or seal gas 182 in the form of nitrogen gas (N 2) was supplied to the cavity at about 2 SLM. According to an exemplary embodiment, the pressure in the cavity chamber 414 and the lower chamber 416 was about 10 Torr. As shown in FIG. 8, at operating conditions of up to about 20 SLM helium gas 192 and 2 SLM nitrogen gas 182, helium gas 192 passes through the purge flow path as evidenced by measurements by a residual gas analyzer (RGA). I did not leak.

  Further, the present specification discloses a method for processing a semiconductor substrate in a processing apparatus. The method includes supplying a process gas from a process gas supply source into a deposition chamber and processing a semiconductor substrate in a plasma processing chamber. The method preferably comprises plasma treating the substrate, wherein RF energy is applied to the process gas using an RF generator and a plasma is generated in the deposition chamber.

  According to one embodiment, the Peclet number may be greater than 100 along the outer periphery of the semiconductor substrate. Preferably, the precursor gas is injected into the center of the reactor cavity with a minimum inlet volume and axisymmetric flow, while simultaneously a seal gas is injected around the outer periphery of the reactor cavity. The precursor gas is reacted to deposit a film on the semiconductor, and by-product gas flows radially outward toward an exhaust outlet that is distributed around the outer periphery of the reactor cavity. At the same time, the seal gas flows radially inward through inlets distributed around the outer periphery of the reactor cavity. In order to achieve a high Peclet number, the gas pressure is controlled according to the following equation:

FIG. 9 illustrates that the showerhead module 400 provides an inert gas seal with gas supplied through the faceplate 402 with the gas outlet 404, the backing plate 406 with the central gas passage 408, and the gas passage 412. , Shows an embodiment comprising an isolation ring 410 having sealing gas passages 412 distributed over the outer periphery of the reaction cavity. Process gas is drawn through a main exhaust passage 414 distributed over the outer periphery of the outer portion of the faceplate 402. In FIG. 9 and the following equations, m ₂ and m _vs represent mass flow in kg / g, C ₂ , C ₃ , and C ₄ represent gas conductance in liters / second, S _eff represents the effective pump speed in liters / second. To achieve a high Peclet number, it is desirable that m _wc is not so large that it exceeds the effective pump speed, as shown below, m _vs is preferably large, and C ₂ is greater than C _3. Preferably, S _eff is preferably large and P _ch may be large (however, a dilution problem occurs):

  During wafer processing, the pressure in the reactor cavity and main chamber is changed to keep the seal gas flow rate constant. If the reactor cavity pressure is maintained at ± 1 Torr relative to the main chamber pressure, it is possible to confine precursor gas within the reactor cavity. The virtual gas seal configuration allows the desired pressure in the reactor cavity to be maintained with an inert gas seal.

FIG. 10 illustrates that the showerhead module 500 provides an inert gas seal with a faceplate 502 having a gas outlet 504, a backing plate 506 having a central gas passage 508, and gas supplied through the gas passage 512. , Shows an embodiment comprising an isolation ring 510 having seal gas passages 512 distributed over the outer periphery of the reaction cavity. A main exhaust passage 514 in which process gas is distributed over the outer periphery of the outer portion of the face plate 502, and a secondary exhaust passage in which the process gas is distributed over the outer periphery of the isolation ring 510 at a position between the gas passage 512 and the main exhaust passage 514. Drawn through. The secondary exhaust passage 516 removes gas through the flow path represented by the flow conductances C ₅ and C ₆ , and the secondary exhaust path C 5 may provide a further increase in the Peclet number according to the following equation:

As shown in FIG. 10, the seal gas is injected from the passage 512 at a position P _vs the small gap between the pedestal module (not shown) and a showerhead module 500, the sealing gas, along the flow path C ₂ It flows radially outward along the radially inward and the channel C ₃ Te. Seal gas flowing in the reaction precursor gas and inwardly is fed in from the reactor cavity 150 through the primary exhaust passage located C ₄ pump. Furthermore, some of the seal gas is pumped through the secondary exhaust passage C ₅ (exhaust passage 516). The mass flow rate of the seal gas is m _vs (seal gas flowing into the narrow gap), m ₂ (seal gas flowing radially inward toward the reactor cavity 150), m ₃ (vacuum of vacuum source connected to the main chamber) The seal gas flowing and removed radially outward by the pressure P _ch ), m ₁ (the seal gas flowing radially inward of the secondary exhaust outlet), and m ₄ (the pump exhausted from the primary exhaust outlet) Sealing gas and process gas). By keeping the C ₅ constant and high Peclet number can be higher than the virtual gas seal one step. A secondary exhaust passage (secondary exhaust) is placed between the seal gas inlet and the reactor cavity to provide conditions for increasing S _eff and C ₅ . The secondary exhaust passage is to ensure a constant exhaust, to C ₅ to provide a constant across conditions, it is preferably connected downstream of the pressure control throttle valve. In FIG. 11, the process gas PG flows radially outward, the seal gas SG flows radially inward, a part of the seal gas SG flows from the secondary exhaust passage, and a part of the inert sealing gas and the process gas. Shows the flow from the main exhaust passage.

  FIG. 12 shows a cutaway view of a showerhead module 600 comprising a face plate 602 having a gas inlet 604, a backing plate 606 having a central gas passage 608, and an isolation ring 610 having an inner ring 612 and an outer ring 614. Show. Inner ring 612 and outer ring 614 fit so that seal 613 around the lower portion of inner ring 612 provides an annular plenum between the opposing surfaces of the inner and outer rings. The inner ring 612 includes a seal gas inlet 616 distributed around the upper portion of the inner surface 618, a horizontal passage 620 extending radially outward from the inlet 616, and a vertical passage 622 extending downward from the horizontal passage 620, And a sealing gas outlet 624 distributed around the lower surface 626 of the inner ring 612.

  Inner ring 612 includes a primary exhaust outlet 627 with radially extending slots distributed around the lower portion of inner surface 618 and a secondary exhaust outlet 628 distributed around lower surface 626. The primary exhaust outlet 627 extends inward with a vertical passage 630 extending upward from the primary exhaust outlet 627 and a primary exhaust outlet 632 distributed around the inner surface 618 at a position below the seal gas inlet 616. Connected to a horizontal passage. The secondary exhaust outlet 628 is connected to a vertical passage (not shown) and a horizontal passage having a secondary exhaust outlet 629 distributed around the outer surface 619 of the inner ring 612. The seal gas outlet 624 supplies a seal gas to form a gas seal under the isolation ring 610, and a portion of the seal gas is a secondary exhaust outlet 628 during semiconductor substrate processing in the wafer cavity 150. Drawn through.

  FIG. 13 shows an inner ring so that seal gas can be supplied from a seal gas supply plenum 650 in the outer portion of a backing plate (gas distribution plate or GDP) 606 to a seal gas passage 652 extending radially outward. A state in which 612 fits on the outer periphery of the face plate 602 and the GDP 606 is shown. Seal gas passage 652 opens into an annular plenum 658 disposed between upper and lower gas seals 654, 656. The annular plenum 658 is in fluid communication with the seal gas inlet 616 on the inner surface 618 of the inner ring 612 to supply seal gas through the seal gas outlet 624 on the lower surface 626 of the inner ring 612.

  The GDP 606 includes a primary exhaust plenum 680 connected to a primary exhaust outlet 682 that extends radially on the outer periphery of the GDP 606. Outlet 682 opens into an annular exhaust plenum 684 between lower seal 656 and annular seal 686. An annular exhaust plenum 684 communicates with the primary exhaust outlet 632 on the inner surface 618 of the inner ring 612. Primary exhaust outlet 632 connects with vertical passage 630 and slot 627 to allow the primary gas to be exhausted from wafer cavity 150.

  The outer ring 614 surrounds the inner ring 612 with a plenum between the outer surface 619 of the inner ring 612 and the inner surface 615 of the outer ring 614. The secondary exhaust outlet 628 provides secondary exhaust that is drawn through the secondary exhaust outlet 629 to the plenum between the inner ring 612 and the outer ring 614. The GDP includes at least one opening 670 on the top surface to allow the secondary exhaust to be withdrawn, bypassing the throttle valve pumping configuration connected to the primary exhaust plenum 680. Preferably, two opposite openings 670 are provided in GDP for azimuthal uniformity of the gas flow.

  FIG. 14 shows two gas seal connections 630, 632 on the top surface of GDP 606 connected to two openings 670 for secondary exhaust removal. Gas connections 630, 632 are attached to two respective tubes 634, 636 connected to a single tube 638 in fluid communication with the exhaust pump, thereby connecting a throttle valve connected to the primary exhaust outlet. Detour. Thus, a portion of the seal gas that forms the gas seal can be withdrawn independently from the primary exhaust.

  Further, when the terms “substantially”, “relatively”, and “substantially” are used in conjunction with a geometric shape, the geometric shape need not be accurate and an acceptable shape is within the scope of the disclosure. Is intended to be included in When used with geometric terms, the terms “substantially”, “relatively”, and “substantially” include not only shapes that meet the strict definition, but also shapes that are very close to the strict definition. I intend to.

  While the plasma processing apparatus having an isothermal deposition chamber has been described in detail with reference to specific embodiments, various changes and modifications can be made and equivalents can be used without departing from the scope of the appended claims. It will be apparent to those skilled in the art that this is possible.

Claims (20)

A chemical vapor deposition chamber having a gas seal,
A showerhead module and a pedestal module configured to support a semiconductor substrate within a wafer cavity under the faceplate;
A gas inlet of the faceplate configured to supply process gas to the wafer cavity;
A primary exhaust outlet configured to remove reactive gas chemicals and inert gases from the wafer cavity;
An annular stage at the outer periphery of the wafer cavity; and an inert gas supply configured to supply an inert seal gas to form a gas seal in the gap between the annular stage and the pedestal module;
A chemical vapor deposition chamber comprising a secondary exhaust outlet disposed radially outward of the primary exhaust outlet and configured to remove at least a portion of the inert gas flowing radially inward through the gap.   The chemical vapor deposition chamber of claim 1, wherein the gas inlet is disposed in an inner portion of the face plate and the primary exhaust outlet is disposed in an outer portion of the face plate.   The chemical vapor deposition chamber according to claim 1, wherein the primary exhaust outlet and the secondary exhaust outlet are disposed on a lower surface of the annular stage.   The chemical vapor deposition chamber of claim 1, further comprising an isolation ring surrounding the face plate, wherein the annular stage includes a lower portion of the isolation ring.   The chemical vapor deposition chamber of claim 1, wherein the primary exhaust outlet is in fluid communication with a pressure controlled throttle valve connected to a vacuum pressure source.   6. The chemical vapor deposition chamber of claim 5, wherein the secondary exhaust outlet is in fluid communication with a constant vacuum pressure source.   The chemical vapor deposition chamber of claim 1, wherein the gap has a width of about 5.0 mm to 25.0 mm from an outer edge of the wafer cavity to an outer edge of the annular step.   The chemical vapor deposition chamber of claim 1, wherein the primary exhaust outlet is in an isolation ring that surrounds the face plate, the isolation ring including an outer periphery of the isolation ring and a backing plate of the showerhead module. A chemical vapor deposition chamber comprising a primary exhaust passage in communication with an annular plenum therebetween.   The chemical vapor deposition chamber of claim 1, wherein the secondary exhaust outlet is in an isolation ring surrounding the face plate, the isolation ring comprising an inner ring and an outer ring, and a secondary exhaust passage is provided. A chemical vapor deposition chamber in communication with an annular plenum between an outer surface of the inner ring and an inner surface of the outer ring.   The chemical vapor deposition chamber of claim 1, wherein the inert gas supply comprises an annular plenum in a backing plate of the showerhead module, the backing plate extending radially outward from the annular plenum. A chemical vapor deposition chamber comprising a seal gas passage in fluid communication with a seal gas outlet on an outer periphery of the backing plate.   The chemical vapor deposition chamber of claim 1, wherein the pedestal module is vertically movable to position the semiconductor substrate within the wafer cavity and loads and unloads the semiconductor substrate onto a substrate pedestal. A chemical vapor deposition chamber that is movable downward to a position for performing.   12. The chemical vapor deposition chamber of claim 11, wherein at least one exhaust passage is disposed in the pedestal module, the at least one exhaust passage is disposed radially outward of the wafer cavity, A chemical vapor deposition chamber configured to remove at least a portion of the inert gas supplied to the gap.   13. The chemical vapor deposition chamber of claim 12, wherein the at least one exhaust passage comprises an annular flow path. A chemical vapor deposition chamber according to claim 4,
(A) The isolation ring includes an inert gas supply port on an inner surface of the isolation ring, the inert gas supply passage extends radially outward from the inert gas supply port, and the inert gas supply passage is Extends vertically downward to the lower surface of the annular step,
(B) The primary exhaust outlet is disposed at a lower portion of the inner surface of the isolation ring, a primary exhaust passage extends upward from the primary exhaust outlet, and the primary exhaust passage is not formed on the inner surface. It extends horizontally to the opening under the active gas supply port,
(C) The chemical vapor deposition chamber in which the secondary exhaust outlet is disposed on a lower surface of the isolation ring, and a secondary exhaust passage extends from the secondary exhaust outlet to an opening on the outer surface of the isolation ring. A method for confining reactive gas chemicals to prevent leakage from a wafer cavity of a chemical vapor deposition chamber, comprising:
(A) supporting the semiconductor substrate on the pedestal module;
(B) flowing a process gas through the gas inlet of the face plate of the showerhead module;
(C) extracting gas from the wafer cavity via a primary exhaust outlet;
(D) maintaining a gas seal in the gap between the stage and the pedestal module by flowing an inert gas through a seal gas outlet on the underside of the showerhead module;
(E) drawing at least a portion of the inert gas flowing radially inward through the gap through a secondary exhaust outlet.   16. The method of claim 15, wherein the primary exhaust outlet is in fluid communication with a pressure controlled throttle valve and the secondary exhaust outlet is in fluid communication with a vacuum source downstream of the pressure controlled throttle valve. .   17. The method according to claim 16, wherein the inert gas is supplied to the gap at a constant flow rate. 16. A method according to claim 15, comprising
Flowing the inert seal gas through the gap with a Peclet number greater than about 100. 16. A method according to claim 15, comprising
Using at least one of processes including chemical vapor deposition, plasma enhanced chemical vapor deposition, atomic layer deposition, plasma enhanced atomic layer deposition, pulse layer deposition, and / or plasma enhanced pulse deposition, a layer is formed on the semiconductor substrate. A method comprising the step of depositing. 16. A method according to claim 15, comprising
Supplying the inert seal gas to the gap at about 100 cc / min to about 5.0 slm (standard liters per minute).