Asymmetric injection for better wafer uniformity

Abstract

A gas injector for processing a substrate comprises: a body having an inlet connectable to a gas source, the gas source being configured to provide a gas flow to the inlet in a first direction when processing a substrate on a substrate support disposed in a processing volume of a processing chamber; and a gas injection channel formed in the body. The gas injection channel is in fluid communication with the inlet and is configured to deliver the gas flow to the inlet of the processing chamber. The gas injection channel has a first inner surface and a second inner surface parallel to a second direction and a third direction. The second direction and the third direction do not intersect the center of the substrate and are angled with the first direction toward a first edge of the substrate support.

Description

Technical Field

[0001] The present disclosure relates generally to semiconductor processing equipment and processing methods, and more particularly to reactors with improved gas flow distribution. Background Art

[0002] When manufacturing memory gate oxides, liner oxides, sacrificial oxides, sidewall oxides, flash tunnel oxides, oxide-nitride-oxide (ONO) stacks, or the like in integrated circuits and microdevices, semiconductor substrates may be processed by rapid thermal oxidation. In this process, an oxide layer may be formed on a substrate by exposing the substrate to an oxygen and hydrogen-based reactive gas while heating the substrate using a radiant heat source to generate oxygen and hydrogen radicals. The oxygen radicals strike the surface of the substrate to form an oxide layer (e.g., a silicon dioxide layer on a silicon substrate).

[0003] In existing process chambers for rapid thermal oxidation, the gas injection means causes the reactive gas to be unevenly distributed over the substrate, resulting in poor thickness uniformity of the oxide layer on the substrate. Conventionally, a rotatable substrate support rotates the substrate while introducing the reactive gas directly toward the center of the substrate. The reactive gas is more distributed in the center of the substrate and less distributed near the edge of the substrate, so that the thickness of the oxide layer grown near the edge of the substrate is less than the thickness at or near the center of the substrate.

[0004] Therefore, there is a need for an improved injection member that allows a more uniform distribution of the reactant gas over the substrate. Summary of the invention

[0005] Embodiments of the present disclosure provide an apparatus for improving gas distribution during thermal treatment. One embodiment of the present disclosure provides an apparatus for thermally treating a substrate. The apparatus comprises: a body, an angled protrusion, and a gas injection channel. The gas injection channel has a first half angle and a second half angle. The first half angle is different from the second half angle.

[0006] Another embodiment of the present disclosure provides an apparatus for processing a substrate, the apparatus comprising: a chamber body defining a processing volume; and a substrate support disposed in the processing volume. The substrate support has a substrate supporting surface. The apparatus also comprises: a gas source protrusion coupled to an inlet of the chamber body; an exhaust assembly coupled to an outlet of the chamber body; and a side gas assembly coupled to a sidewall of the chamber body. The side gas assembly comprises: a gas injection channel. The gas injection inlet comprises: a first half angle and a second half angle. The first half angle is different from the second half angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order that the manner in which the above-mentioned features of the present disclosure can be understood in detail, a more specific description of the present disclosure briefly summarized above may be obtained by reference to embodiments, some of which are shown in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure and are not to be considered as limiting its scope, as the present disclosure may admit of other equally effective embodiments.

[0008] Figure 1A is a schematic cross-sectional view of a processing chamber according to one embodiment.

[0009] Figure 1B is a schematic cross-sectional top view of a processing chamber according to one embodiment.

[0010] Figure 2A and Figure 2B FIG. 1 is a numerical simulation of the oxygen radical concentration on a substrate according to an embodiment.

[0011] Figure 3A is a schematic cross-sectional top view of a gas injector according to one embodiment.

[0012] Figure 3B and Figure 3C is a three-dimensional schematic diagram of a gas injector according to one embodiment.

[0013] Figure 4 is a schematic cross-sectional top view of a gas injector according to one embodiment.

[0014] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in some embodiments may be beneficially utilized on other embodiments without specific recitation. DETAILED DESCRIPTION

[0015] Embodiments described herein generally relate to a semiconductor processing apparatus and processing method, and more particularly to a reactor with improved gas flow distribution. Embodiments of the present disclosure provide an asymmetric gas injector comprising: a gas injection channel configured to inject gas toward an edge of a substrate disposed in a processing chamber, thereby increasing the reaction with the gas at or near the edge of the substrate. Embodiments of the present disclosure further provide a side pump configured to redirect the gas toward the opposite edge of the substrate, thereby increasing the reaction on the substrate surface and the opposite edge of the substrate. Therefore, the layer formed on the substrate by the injected gas is uniform over the entire substrate surface.

[0016] In the following description, an orthogonal coordinate system including an X-axis, a Y-axis, and a Z-axis is used. For the sake of convenience, it is assumed that the direction indicated by the arrow in the figure is a positive direction.

[0017] Figure 1A 1 is a schematic cross-sectional view of a processing chamber 100 according to one embodiment. The processing chamber 100 generally includes a lamp assembly 110, a chamber body 130 defining a processing volume 139. A substrate support 138 is disposed in the processing volume 139 and lies in an XY plane. The processing chamber 100 provides a controlled thermal cycle that heats a substrate 101 to perform one or more thermal processes (e.g., thermal annealing, thermal cleaning, thermal chemical vapor deposition, thermal oxidation, and thermal nitridation) on the substrate 101.

[0018] The lamp assembly 110 can be relatively positioned above the substrate support 138 in the Z direction to supply heat to the processing volume 139 via the quartz window 114. The quartz window 114 is disposed between the substrate 101 and the lamp assembly 110 in the Z direction. In some embodiments, the lamp assembly 110 can additionally or alternatively be disposed below the substrate support 138 in the Z direction. The lamp assembly 110 accommodates a heating source 108 (e.g., a tungsten halogen lamp) for providing infrared heating means to the substrate 101 disposed on the substrate support 138. The tungsten halogen lamps can be arranged in a hexagonal arrangement. The heating source 108 can be controlled by the controller 107 to achieve a uniform or customized heating curve for the substrate 101. In some embodiments, the heating source 108 can rapidly heat the substrate 101 at a rate from about 5°C / s to about 280°C / s.

[0019] The substrate 101 may be heated to a temperature in a range from about 450° C. to about 1100° C. The heating source 108 may provide temperature regulation at certain locations of the substrate 101 while not affecting the temperature at other locations. A slit valve 137 may be disposed on the base ring 140 for a robot to transfer the substrate 101 to and from the processing volume 139. The substrate 101 may be placed on a substrate support 138. The substrate support 138 may be vertically movable in the Z direction and rotated about the central axis 123 in the XY plane. A gas inlet (also referred to as a chamber gas inlet) 131 may be disposed on the base ring 140 in the Z direction and connected to a gas source 152.

[0020] Figure 1B is a schematic cross-sectional top view of the processing chamber 100. Figure 1B As shown in FIG, the gas inlet 131 and the gas outlet (also referred to as the chamber gas outlet) 134 are disposed on opposite sides of the processing volume 139 in the X direction. The gas inlet 131 and the gas outlet 134 may have a linear or azimuthal width approximately equal to the diameter of the substrate support 138.

[0021] Reference Figure 1A and Figure 1B both, the gas outlet 134 (formed on the side of the base ring 140 opposite the gas inlet 131 (in the X direction)) is an exhaust assembly 124, which is in fluid communication with a first main exhaust pump 160 and a second main exhaust pump 136 on the side walls of the chamber body 130 having openings 160A and 136A (these openings are opposite each other in the Y direction). The exhaust assembly 124 defines an exhaust volume 125. The exhaust volume 125 is in fluid communication with the processing volume 139 via the gas outlet 134. In some embodiments, the gas outlet 134 may include a perforated plate 135, which includes a series of through-holes configured to restrict the airflow therethrough and thus provide a uniform extraction of the gas from the processing volume 139 (i.e., uniform in the Y-Z plane). However, in other embodiments, the perforated plate 135 is not used in the processing chamber 100 or is configured to provide a minimum restriction to the airflow from the processing volume 139 to the exhaust volume 125, allowing the positions of the openings 160A and 136A to affect the flow pattern within the processing volume 139 and the exhaust volume 125. In one example, as Figure 1B shown, the openings 160A and 136A are configured such that the flow pattern in the rear portion of the processing volume 139 and the exhaust volume 125 is higher at the left extension of the processing volume 139 (i.e., near the second edge 302) due to the position of the opening 136A and higher at the right extension of the processing volume 139 (i.e., near the first edge 304) due to the position of the opening 160A, so that there is a proportionally smaller flow in the middle of the rear portion of the processing volume 139 and the exhaust volume 125. In another example, the second main exhaust pump 136 is closed and the first main exhaust pump 160 is used to pump gas from the processing volume 139 and the exhaust volume 125 via the opening 160A such that the flow pattern in the rear portion of the processing volume 139 and the exhaust volume 125 is higher at the right extension of the processing chamber due to the position of the opening 160A, resulting in an increasing flow gradient from the left to the right of the rear portion of the exhaust volume 125 and the processing volume 139 (e.g., an increasing gradient in the –Y direction). In yet another example, the first main exhaust pump 160 is closed and the second main exhaust pump 136 is used to pump gas from the processing volume 139 and the exhaust volume 125 via the opening 136A such that the flow pattern in the rear portion of the processing volume 139 and the exhaust volume 125 is higher at the left extension of the processing chamber due to the position of the opening 136A, resulting in an increasing flow gradient from the right to the left of the rear portion of the exhaust volume 125 and the processing volume 139 (e.g., an increasing gradient in the +Y direction).

[0022] In some embodiments, the side port 122 can be formed in the base ring 140 located on the sidewall of the chamber body 130 (on which the first main exhaust pump 160 is located) and near the first edge 304 of the processing volume 139 and between the gas inlet 131 and the gas outlet 134 in the X direction (at Figure 1B The side port 122, the gas inlet 131 and the gas outlet 134 may be arranged at substantially the same level in the Z direction. The side port 122 is in fluid communication with the side exhaust pump 300 (at Figure 1B (see figure in the figure).

[0023] The gas source 152 may include one or more gas sources (e.g., a first gas source 153 and a second gas source 154), each of which provides a process gas to the injection box 149. In some embodiments, the first gas source 153 is a remote plasma source (RPS) that generates oxygen and hydrogen radicals. For heating the substrate 101 with a lamp and injecting hydrogen and oxygen radicals into the processing volume 139, the first gas source 153 may be a remote plasma source (RPS) that generates oxygen and hydrogen radicals. In the process, a gas injector 147 in fluid communication with the gas inlet 131 and the gas source 152 may be connected to the base ring 140. A flow adjustment device 146 may be placed between the gas source 152 and the gas injector 147 to control the flow rate of the gas flow 148. It is believed that during the oxidation process, the introduction of hydrogen radicals improves the reaction rate along the edge of the substrate 101 when the substrate is rotated, resulting in an oxide layer with improved thickness uniformity. The gas flow 148 may contain 5 to 80 percent hydrogen by volume and 20 to 95 percent oxygen by volume, and has a flow rate ranging from about 1 slm to about 50 slm. In some embodiments, the gas mixture also has an argon concentration in the range of about 5% to about 80% (e.g., in the range of about 10% to about 50%). For a substrate having a diameter of 300 mm, the flow rate ranges from about 0.007 slm / cm 2 to about 0.035slm / cm 2 The composition, pressure, and flow rate of the gas flow 148 affect the thickness uniformity of the oxide layer formed on the substrate 101 .

[0024] Gas flows from a gas source 152, optionally through an injector box 149, a gas injector 147, and a gas inlet 131 into the processing volume 139. In some embodiments, the injector box 149 has an elongated channel 150 and an inlet (also referred to as an injector inlet) 143 formed therein. Injection holes 151 are distributed along the elongated channel 150 and are configured to inject a primary gas flow 145 toward the processing volume 139 in a direction at an angle to the X direction. In some embodiments of the oxidation process, the primary gas flow 145 may include 5 to 80 percent hydrogen by volume and 20 to 95 percent oxygen by volume, and has a flow rate ranging from about 1 standard liter per minute (slm) to about 50 slm when the chamber is maintained at a pressure of about 1 Torr to about 19 Torr (e.g., between about 5 Torr to about 15 Torr) and the substrate is heated to a temperature between about 450° C. and about 1100° C. In some embodiments, the gas mixture also has an argon concentration in a range of about 5% to about 80%, such as in a range of about 10% to about 50%. The flow rate is based on a substrate 101 having a diameter of 300 mm, which results in a range from about 0.011 slm / cm 2 to about 0.071slm / cm 2 Flow rate.

[0025] The primary gas flow 145 is directed from the gas flow 148 (and optionally also from the injection hole 151) in the X direction toward the gas outlet 134. The primary gas flow 145 flows into the exhaust volume 125 and is exhausted by one or both of the first main exhaust pump 160 and the second main exhaust pump 136. It is believed that the geometry of the processing chamber 100 (e.g., the location, shape, and direction of the exhaust volume 125), the size and location of the openings 160A, 136A of the first main exhaust pump 160 and the second main exhaust pump 136, and the pumping speeds achieved by the first main exhaust pump 160 and the second main exhaust pump 136 can be used to influence the gas flow pattern and thus the flow uniformity in the processing volume 139. However, in some alternative embodiments, the exhaust volume 125 of the exhaust assembly 124 extends along the direction of the primary gas flow 145 so that the effect of the geometry of the processing volume 139 on the primary gas flow 145 is reduced (e.g., positioned sufficiently far from the gas inlet 131).

[0026] The first main exhaust pump 160 and the second main exhaust pump 136 may also be used to control the pressure of the processing volume 139. In some embodiments, the pressure within the processing volume 139 is maintained at about 0.5 Torr to about 19 Torr (e.g., between about 5 Torr to about 15 Torr). In some embodiments, the process performed in the processing volume 139 operates within a viscous flow regime. In this case, the first main exhaust pump 160 and the second main exhaust pump 136 draw a certain amount of gas to the corresponding openings 160A, 136A of the first main exhaust pump 160 and the second main exhaust pump 136, push the amount of gas through the pumping member, and exhaust the amount of gas to the pump inlet at atmospheric pressure. Therefore, as discussed above, a gradient of gas concentration is generated (i.e., the gas concentration is lower near the pump inlet and higher away from the pump inlet), thereby causing the gas in the processing volume 139 to flow toward the pump inlet.

[0027] exist Figure 1B In one example embodiment shown in FIG. 1 , the gas injector 147 is an asymmetric structure having an opening that directs a majority of the main gas flow 145 from the gas inlet 131 toward the second edge 302 of the processing volume 139. Thus, at or near the second edge 302 of the processing volume 139, gas exposure of the substrate 101 is increased. In some embodiments, the main gas flow 145 is exhausted by the first main exhaust pump 160 and the second main exhaust pump 136 on either side of the chamber body 130. In some embodiments, the main gas flow 145 directed toward the second edge 302 of the processing volume 139 is redirected toward the first edge 304 of the processing volume 139 by the use of the side exhaust pump 300. The side exhaust pump 300 can create a gradient of gas concentration (i.e., the gas concentration is lower near the pump inlet of the side exhaust pump 300 and higher away from the pump inlet of the side exhaust pump 300) so that the gas within the processing volume 139 flows toward the pump inlet of the side exhaust pump 300.

[0028] In some embodiments, the main gas flow 145 redirected toward the first edge 304 of the processing volume 139 is exhausted by the side exhaust pump 300 and the first main exhaust pump 160, while the second main exhaust pump 136 is turned off. In some embodiments, the ratio of the exhaust flow rate of the side exhaust pump 300 to the exhaust flow rate of the first main exhaust pump 160 is between 0.5:1 and 1:0.5. In other embodiments, the side exhaust pump 300 and the first main exhaust pump 160 and the second main exhaust pump 136 are turned on. Therefore, in some embodiments, the ratio between the exhaust flow rate of the side exhaust pump 300 and the exhaust flow rate of the first main exhaust pump 160 plus the exhaust flow rate of the second main exhaust pump 136 is between 0.5:1 and 1:0.5.

[0029] In some embodiments, the substrate 101 may be rotated in a counterclockwise direction 197 as the gas is directed toward the edge of the substrate 101, thereby causing the gas to flow over the substrate 101, resulting in more uniform growth on the substrate 101. The rotation of the substrate 101 (in the opposite direction of the gas flow) may be used to redirect the primary gas flow 145 toward the first edge 304 of the processing volume 139, while the gas injector 147 directs the primary gas flow 145 toward the second edge 302 of the processing volume 139. The speed and flow pattern of the primary gas flow 145 in the processing volume 139 may be adjusted via the rotation speed of the substrate 101 and the tilt angle (hereinafter referred to as the cone angle θ) of the gas injection channel of the gas injector 147, thereby reducing non-uniformity of the primary gas flow 145 on the substrate 101. In some embodiments, the rotation speed of the substrate ranges between about 5 and 300 rpm, and the cone angle θ may be between 10° and 35°. Thus, the thickness profile at the edge of the substrate is improved. In some embodiments, the substrate 101 may be rotated in a clockwise direction opposite to the counterclockwise direction 197 to further increase the gas velocity along the edge in order to obtain a different desired thickness profile.

[0030] When the main gas flow 145 (gas or radical gas) is directed in a direction toward the edge of the substrate 101 (or the edge of the substrate supporting surface of the substrate support 138) near the second edge 302 of the processing volume 139, the gas or radical gas significantly increases the reaction rate along the edge of the substrate 101 near the second edge 302 of the processing volume 139 (compared to at or near the center 308 of the substrate 101) when the substrate is rotated. Compared to directing the gas toward the center 308 of the substrate 101, the reaction rate of the substrate 101 is significantly increased by the asymmetric gas injection channel 249 (at the center of the substrate 101) with or without the side exhaust pump 300. Figure 3A Directing the gas toward the edge of the substrate 101 near the second edge 302 of the processing volume 139 (shown in FIG. 1 ) results in an oxide layer having improved thickness uniformity across the substrate 101. In one example of an oxidation process, the main gas flow 145 may include 5 to 80 percent hydrogen by volume and 20 to 95 percent oxygen by volume, optionally an argon concentration in the range of about 5% to about 80%, a flow rate in the range of about 1 standard liter per minute (slm) to about 50 slm, while the chamber is maintained at a pressure of about 0.5 Torr to about 19 Torr, and the substrate is heated to a temperature between about 450° C. and about 1100° C. and rotated in a counterclockwise direction at a speed between about 10 rpm and 300 rpm.

[0031] Figure 2A and Figure 2BThe numerical simulation of the oxygen radical concentration on the substrate 101 having a diameter of 300 mm is shown, which varies with the position along the line in the Y direction intersecting the center 308 of the substrate 101. The position indicated as "0" corresponds to the center 308 of the substrate 101. Figure 2A In the embodiment, the side exhaust pump 300 is turned off, and the first main exhaust pump 160 and the second main exhaust pump 136 are turned on. Figure 2B In the process, the side exhaust pump 300 and the first main exhaust pump 160 are turned on. Figure 2A and Figure 2B In the numerical simulation indicated by (a), the cone angle θ is assumed to be 15°, and in the numerical simulation indicated by (b), the cone angle θ is assumed to be 25°. Figure 2A In the case of cone angles θ of 15° and 25°, respectively, the oxygen radical concentration decreases at the center 308 of the substrate 101 (i.e., the position indicated as “0”) and diffuses toward the edge of the substrate 101 (i.e., the positions indicated as “150” and “−150”). Figure 2B , for the cases where the cone angle θ is 15° and 25° respectively, the oxygen radical concentration decreases at the center 308 of the substrate 101 (i.e., the position indicated as “0”) and diffuses toward the edge of the substrate 101 (i.e., the positions indicated as “150” and “-150”).

[0032] Figure 3A is a schematic cross-sectional top view of a gas injector 147 according to one embodiment. The gas injector 147 may be made of any suitable material, such as quartz, ceramic, aluminum, stainless steel, steel, or the like.

[0033] The gas injector 147 has a body 230 in which a gas injection passage 249 and an opening 246 are formed. In some embodiments, the opening 246 is rectangular.

[0034] In some embodiments, the body 230 is a parallelepiped. The body 230 has a first side 232 opposite to a second side 234. In some embodiments, the first side 232 and the second side 234 are parallel to the X-axis and have substantially the same length. The body 230 has a third side 224, a fourth side 222, a fifth side 226, and a sixth side 282. Figure 3B ).

[0035] The cross-section of the gas injection passage 249 may have any desired shape, such as a rectangular shape (in Figure 3B), square, circular, polygonal, hexagonal, trapezoidal or any other suitable shape. The gas injector 147 is adapted to direct a majority of the main gas flow 145 to the second edge 302 of the processing volume 139. The gas injection channel 249 includes two inner surfaces 279, 280 ( Figure 3A ). In some embodiments, the inner surface 279 extends along a direction 306 that is substantially tangential to an edge of the substrate supporting surface of the substrate support 138 near the second edge 302 of the processing volume 139. The inner surface 280 of the gas injection channel 249 is inclined from the axis 210 toward the inner surface 279 by a taper angle θ. The axis 210 extends through the opening 246 and is parallel to the X direction and perpendicular to the fifth side 226 (at Figure 3B ). The inner surfaces 279, 280 are arranged along a direction inclined from the axis 210 toward the second edge 302, and the projections of these surfaces (which are all parallel to the XY plane) are configured not to intersect the center 308 of the substrate 101. The cone angle θ may be between 5° and 45°. The inner surfaces 279, 280 extend from the opening 246 to the sixth side 282 (at Figure 3B The sixth side 282 is curved and adjacent to the substrate 101 and on the opposite side of the opening 246 .

[0036] In some embodiments, the opening 246 has a circular entrance 216 (eg, Figure 3B ). The circular inlet 216 leads to the enlarged interior space 214 ( Figure 3A ). In some embodiments, the enlarged interior space 214 has a rectangular cross-sectional shape in the YZ plane.

[0037] Figure 3B and Figure 3C is a three-dimensional schematic diagram of the gas injector 147. The gas injector 147 has the function of directing the majority of the gas or radical gas found in the main gas flow 145 towards the second edge 302 of the processing volume 139.

[0038] The gas injector 147 includes sides 226, 232, 234, 282, 224 and 222. The first side 232 is opposite to the second side 234. In some embodiments, the first side 232 and the second side 234 are parallel to the X-axis and have substantially the same length. The first curved surface 236 is disposed between the first side 232 and the third side 224. The third side 224 is disposed to be orthogonal to the first side 232. The second curved surface 240 is disposed between the second side 234 and the third side 224. The third curved surface 238 is disposed between the first side 232 and the fourth side 222. The fourth side 222 is orthogonal to the first side 232. The fourth curved surface 228 is disposed between the second side 234 and the fourth side 222. The third side 224 is opposite to the fourth side 222. The fifth side 226 is opposite to the sixth side 282. In some embodiments, the sixth side 282 is curved. In one example, the radius of curvature of the sixth side 282 may be between about 160 mm and about 230 mm. In another example, the radius of curvature of the sixth side 282 can be between about 10 mm and about 80 mm greater than the radius of the substrate to be processed in the processing volume 139. The gas injection channel 249 is disposed on the sixth side 282 facing the substrate 101. The first side 232 and the second side 234 can be substantially perpendicular to the fourth side 222, allowing for a tighter seal within the processing chamber 100. When the sixth side 282 is curved so that the curvature conforms to the curvature of the substrate 101, turbulent gas flow in the gas flow toward the substrate 101 is reduced, resulting in uniformity in the gas flow.

[0039] Figure 4 A schematic cross-sectional top view of a gas injector 147 according to another embodiment is shown. As shown, the gas injector 147 includes a body 230 in which a gas injection passage 249 is formed. The gas injection passage 249 has two inner surfaces 279, 280 and a plurality of linear rudders 220. Although only two linear rudders 220 are shown in FIG. Figure 4 In the embodiment shown in FIG. 1 , it should be understood that any number of linear rudders 220 may be included in the gas injector 147. The body 203 and the linear rudders 220 may be made of quartz or any other material that does not react with the reactive gas. The gas injector 147 is divided into a first portion 231 and a second portion 229 by a dividing line 215, wherein the dividing line 215 is parallel to the Y direction. A plurality of linear rudders 220 are disposed in the first portion 231. The first portion 231 and the second portion 229 may be made as two separate parts of the gas injector 147 for combination, or the first portion 231 and the second portion 229 may be made of the same part. The gas injector 147 is coupled to the inlet 143, and the inlet 143 delivers the reactive gas to the gas injector 147. The gas injector 147 is configured to deliver the reactive gas to the substrate 101.

[0040] The gas injector 147 is divided into a top portion 235 and a bottom portion 233 by an axis 210, wherein the axis 210 is parallel to the X direction. According to one embodiment, the linear rudder 220 is arranged and tilted in such a manner that the reactant gas flows mostly or completely through the top portion 235 of the gas injector 147. If the reactant gas is allowed to flow through the bottom portion 233 of the gas injector 147, a large portion of the reactant gas will miss most of the substrate area and remain unreacted or be sucked into the side port 122 and then sucked into the side exhaust pump 300, thereby wasting the reactant gas and causing uneven film growth on the portion of the substrate disposed at the right extension of the processing volume 139 (i.e., near the first edge 304). In addition, without the rudder, the gas injector 147 exhibits a jet-like flow in which the main gas flow 145 is concentrated in a narrow stream. The gas injector 147 with the rudder 220 disclosed herein allows the primary gas flow 145 to be diffused over a much wider area while still being concentrated on the left extension of the processing volume 139 (ie, near the second edge 302).

[0041] The main gas flow 145 through the top portion 235 of the gas injector 147 allows film growth mainly or completely on the portion of the substrate 101 in the left extension of the processing volume 139, i.e. near the second edge 302. In addition, the increased circulation of the reactive gas due to the linear rudder 220 increases the reaction rate of the reactive gas with the substrate 101, resulting in faster film growth. The linear rudder 220 is arranged so that the integrated velocity of the reactive gas at the left extension of the processing volume 139 near the second edge 302 is as high as possible, while the integrated velocity is still as uniform as possible in the left extension of the processing volume 139 near the second edge 302. Compared to other rudder shapes (e.g. wedge-shaped), the linear rudder 220 allows a higher velocity of the main gas flow 145.

[0042] The plurality of linear rudders 220 may be disposed in any arrangement within the first portion 231 of the gas injector 147. The plurality of linear rudders 220 have an angle α relative to the axis 210 toward the second edge 302 of the processing volume 139. According to some embodiments, each of the linear rudders 220 may have the same angle α or a different angle. According to some embodiments, the angle α varies from about 5° to about 85° (e.g., from about 25° to about 55°, or from about 35° to about 45°). According to one embodiment, an end 220E of at least one of the plurality of linear rudders 220 is separated from the bottom surface 202 by a distance of about 15 mm to about 60 mm. According to one embodiment, an end 220E of at least one of the plurality of linear rudders 220 is separated from the separation line 215 by a distance of about 35 mm to about 45 mm. According to one embodiment, a linear rudder in the plurality of linear rudders 220 has a length of from about 25 mm to about 75 mm. According to one embodiment, the plurality of linear rudders 220 are arranged so that the main gas flow 145 of the reaction gas coming out of the gas injector 147 has a Reynolds number (Re) of about 100 or less, and the main gas flow 145 is laminar.

[0043] In some embodiments, the substrate 101 may be heated from a temperature of about 23° C. to about 1200° C. during delivery of the reactive gas to the surface of the substrate 101. The reactive gas may be delivered such that the reactive gas grows a film on a portion of the substrate 101 in a left extension of the processing volume 139 near the second edge 302. About 60% to about 90% or more of the volume of the film is disposed in the left extension of the processing volume 139 near the second edge 302.

[0044] Although thermal processing chambers are discussed in this application, embodiments of the present disclosure may be used in any processing chamber where uniform gas flow is desired.

[0045] Benefits of the present disclosure include: Controlling growth uniformity across a substrate using an asymmetric gas injector in a processing chamber to direct gas toward the edge of a substrate. The asymmetric gas injector directs gas flow toward the edge of the processing volume. The gas flow can further be redirected to the other edge of the processing volume by a side pump. Specifically, it has been observed that directing gas through an asymmetric gas channel will significantly increase the uniformity of the substrate growth. The reaction during the process is at or near the edge of the substrate, resulting in improved thickness uniformity along the edge of the substrate, and improved overall thickness uniformity of the substrate.

[0046] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, which is to be determined by the claims that follow.

Claims

1. A gas injector for processing a substrate, comprising: a body having an inlet connectable to a gas source, the gas source configured to provide a gas flow to the inlet in a first direction when processing a substrate on a substrate support, the substrate support disposed within a processing volume of a processing chamber, wherein the substrate support has a first edge and a second edge, the second edge being opposite the first edge in a direction orthogonal to the first direction; and a gas injection passage formed in the body, wherein The gas injection channel is in fluid communication with the inlet, The gas injection channel is configured to deliver the gas flow to a process chamber inlet of the process chamber, The gas injection channel has a first inner surface parallel to the second direction and a second inner surface parallel to the third direction, and the first inner surface and the second inner surface are formed in one gas injection channel. The first direction, the second direction and the third direction are parallel to the first plane, The second direction and the third direction do not intersect the center of the substrate and are angled with the first direction toward the second edge of the substrate support; The second direction is inclined from the first direction toward the second edge of the substrate support by between 15° and 35°, and The third direction is substantially tangential to the second edge of the substrate support.

2. The gas injector of claim 1, further comprising: a first side, the first side being parallel to the first direction; a second side, the second side being parallel to the first direction and opposite to the first side in a fourth direction orthogonal to the first direction, the second side having substantially the same length as the first side; a third side, the third side being parallel to the fourth direction; a first curved surface extending between the first side and the third side; a second curved surface extending between the third side and the second side; a fourth side, the fourth side being parallel to the fourth direction and opposite to the third side in a fifth direction orthogonal to the first direction and the fourth direction; a third curved surface extending between the first side and the fourth side; a fourth curved surface extending between the fourth side and the second side; a fifth side, the fifth side being parallel to the fourth direction; and a sixth side parallel to the fourth direction and opposite to the fifth side in the first direction, wherein the inlet is disposed on the fifth side and the gas injection channel is disposed on the sixth side.

3. The gas injector of claim 1, further comprising: A plurality of linear rudders are disposed in the gas injection passage.

4. The gas injector of claim 3, wherein Each of the plurality of linear rudders is inclined between 25° and 55° from the first direction toward the second edge of the substrate support, and An end of at least one of the plurality of linear rudders is separated from an inner surface of the gas injection passage by a distance between 15 mm and 60 mm.

5. An apparatus for processing a substrate, comprising: a chamber body having a chamber gas inlet, a chamber gas outlet, and a processing volume, the processing volume being between the chamber gas inlet and the chamber gas outlet in a first direction; a substrate support disposed within the processing volume; A gas injector having an injector inlet and a gas injection channel, wherein The injector inlet is connectable to a gas source configured to provide a gas flow to the injector inlet in the first direction when processing a substrate on the substrate support, The gas injection passage is in fluid communication with the injector inlet, and The gas injection channel is configured to deliver the gas flow to the chamber gas inlet; an exhaust assembly coupled to the chamber gas outlet, the exhaust assembly comprising a first main exhaust pump; and a side exhaust pump coupled to the processing volume via a side port of the chamber body, wherein The side port is disposed adjacent to a first edge of the substrate support, The gas injection channel has a first inner surface parallel to the second direction and a second inner surface parallel to the third direction, and the first inner surface and the second inner surface are formed in one gas injection channel. The first direction, the second direction and the third direction are parallel to the first plane, The second direction and the third direction do not intersect the center of the substrate and are angled with the first direction toward a second edge of the substrate support, the second edge being opposite to the first edge in a fourth direction orthogonal to the first direction, The second direction is inclined from the first direction toward the second edge of the substrate support by between 15° and 35°, and The third direction is substantially tangential to the second edge of the substrate support.

6. The apparatus of claim 5, wherein the substrate support is rotatable about the center of the substrate.

7. The apparatus of claim 5, wherein the exhaust assembly further comprises a second main exhaust pump.

8. The apparatus of claim 5, wherein the gas injector further comprises a plurality of linear rudders disposed within the gas injection passage.

9. The device of claim 8, wherein Each of the plurality of linear rudders is inclined between 25° and 55° from the first direction toward the second edge of the substrate support, and An end of at least one of the plurality of linear rudders is separated from an inner surface of the gas injection passage by a distance between 15 mm and 60 mm.

10. A method for processing a substrate, comprising: When processing a substrate on a substrate support disposed within a processing volume of a processing chamber, a gas flow is injected from a gas source to a gas injector in a first direction, the substrate support having a first edge and a second edge, the second edge being opposite the first edge in a direction orthogonal to the first direction, wherein The processing chamber has a chamber gas inlet and a chamber gas outlet, and the substrate support is disposed between the chamber gas inlet and the chamber gas outlet in the first direction; and The gas flow is injected from the gas injector into the processing chamber, wherein The gas flow from the gas injector is directed between a second direction and a third direction, and The second direction and the third direction do not intersect the center of the substrate disposed on the substrate support and are angled with the first direction toward the second edge of the substrate support. ； and The gas injector comprises: a body having an inlet connectable to the gas source, the gas source being configured to provide the gas flow to the inlet in the first direction when processing the substrate; and a gas injection passage formed in the body, wherein The gas injection passage is in fluid communication with the inlet; The gas injection channel is configured to deliver the gas flow to a process chamber inlet of the process chamber; The gas injection channel has a first inner surface parallel to the second direction and a second inner surface parallel to the third direction, and the first inner surface and the second inner surface are formed in one gas injection channel; The first direction, the second direction and the third direction are parallel to the first plane; The second direction is inclined between 15° and 35° from the first direction toward the second edge of the substrate support; and The third direction is substantially tangential to the second edge of the substrate support.

11. The method of claim 10, further comprising: The substrate support is rotated about the center of the substrate.

12. The method of claim 11, further comprising: The gas flow is exhausted from the chamber gas outlet by a first main exhaust pump disposed on a first side of the processing chamber and a second main exhaust pump disposed on a second side of the processing chamber, the second side being opposite to the first side in a fourth direction orthogonal to the first direction.

13. The method of claim 11, further comprising: The gas flow is exhausted from the chamber gas outlet by a first main exhaust pump disposed on a first side of the processing chamber and from the processing volume by a side exhaust pump disposed on the first side of the processing chamber near the first edge of the substrate support.

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