Vented susceptor

Abstract

To disclose, generally, semiconductor processing, and more specifically, susceptors for supporting semiconductor substrates in process chambers.SOLUTION: A susceptor can include a face that is configured to support a substrate thereon, and a plurality of channels extending into the face and radially outwardly relative to a center of the face. One or more of the channels may include an elongate portion and a flash-out portion. The elongate portion may have a width less than a threshold width along the entirety of the elongate portion. The flash-out portion may be in fluid communication with the elongate portion and may include a first section having a first width and a second section having a second width greater than the first width. The first section may be disposed radially inward of the second section.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to semiconductor processing, and more particularly to a susceptor for supporting a semiconductor substrate within a processing chamber. [Background technology]

[0002] 2. Description of Related Art Semiconductor manufacturing processes are typically performed with a substrate supported in a reaction chamber on a susceptor under controlled process conditions. In many processes, the semiconductor substrate (e.g., a wafer) is heated within the reaction chamber. Several quality control issues related to physical interactions between the substrate and the susceptor can arise during processing. Summary of the Invention [Means for solving the problem]

[0003] FIELD OF THE DISCLOSURE The present disclosure relates generally to semiconductor processing, and more particularly to a susceptor for supporting a semiconductor substrate within a processing chamber. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a schematic diagram of an embodiment of a semiconductor processing apparatus including a reaction chamber and a loading chamber with a susceptor in a loading position. [Figure 2] FIG. 2 shows the apparatus of FIG. 1 with the susceptor in the processing position. [Figure 3] FIG. 3 is an exemplary susceptor that can be used to support a substrate (eg, a wafer). [Figure 4A] FIG. 4A is another example susceptor, according to some embodiments. [Figure 4B] FIG. 4B is a perspective view of the backside of the susceptor shown in FIG. 4A. [Figure 5] FIG. 5 is a detailed view of a portion of the susceptor shown in FIG. 4A. [Figure 6]FIG. 6 is a cross-sectional view of an exemplary channel. [Figure 7A] FIG. 7A is a perspective view of a vector map showing the magnitude and direction of velocity of gas flow through a channel. [Figure 7B] FIG. 7B is a perspective view of a vector map showing the magnitude and direction of the velocity of gas flow through the channel. [Figure 7C] FIG. 7C is a perspective view of a vector map showing the magnitude and direction of the velocity of gas flow through the channel. [Figure 8] FIG. 8 is a heat map of pressure across an exemplary susceptor. DETAILED DESCRIPTION OF THE INVENTION

[0005] Susceptors are typically formed by machining graphite into the desired shape and applying a silicon carbide (SiC) coating or by sintering a layer of aluminum nitride. Susceptors can be formed into a variety of shapes, but are most often round.

[0006] As mentioned above, many quality control issues can occur during processing related to the physical interaction between the substrate and the susceptor. These issues include, for example, substrate sliding, sticking, curling, and backside deposition. These quality control issues can reduce the overall quality of the substrate and semiconductor device, resulting in lower yields and increased costs.

[0007] Backside deposition occurs when process gases flow into the space between the substrate and the susceptor and deposit on the backside of the substrate. Because the flow of process gases is not controlled between the substrate and the susceptor, random deposition can occur on the backside of the substrate. This random deposition can cause thickness variations on the backside, which can affect the local planarity on the front side and ultimately cause device uniformity issues.

[0008] In a typical process, reactant gases are passed over a heated wafer, causing atomic layer deposition (ALD) of thin layers of reactants onto the wafer. Sequential processing builds up multiple layers into an integrated circuit. Other exemplary processes include sputter deposition, photolithography, dry etching, plasma processing, and high-temperature annealing. Many of these processes require high temperatures and can be performed in the same or similar reaction chambers.

[0009] Wafers may be processed at a variety of temperatures to promote high-quality deposition. Temperature control is particularly beneficial at temperatures below the mass transport region, e.g., approximately 500°C to 900°C for silicon CVD using silane. In this dynamic region, if the temperature is not uniform across the wafer's surface, the deposited film thickness will be non-uniform. However, lower temperatures may be used in certain scenarios.

[0010] Wafers are made of silicon and most commonly have a diameter of about 150 mm (about 6 inches) or about 200 mm (about 8 inches) and a thickness of about 0.725 mm. Recently, larger silicon wafers have been used, with diameters of about 300 mm (about 12 inches) and thicknesses of about 0.775 mm, to more efficiently utilize the benefits of single-wafer processing. Even larger wafers are expected in the future. A typical single-wafer susceptor has a pocket or recess into which the wafer rests during processing. The recess is often shaped to receive the wafer very closely.

[0011] There are various quality control issues associated with substrate handling. These issues include substrate sliding, adhesion, and curling. These issues arise primarily during the placement and subsequent removal of substrates from high-temperature process chambers, especially single-wafer chambers.

[0012] Substrates may be moved within the reaction chamber, for example, to and from the susceptor, by an effector or other robotic substrate handling device, such as a Bernoulli wand, as described in U.S. Patent No. 5,997,588, the entire disclosure of which is incorporated herein by reference for all purposes.

[0013] Substrate "sliding" or "skating" occurs during substrate removal when a cushion of gas within the susceptor, e.g., within a recess or pocket in the susceptor on top of the susceptor, cannot escape quickly enough to quickly and accurately transport the substrate from the effector onto the susceptor. If the gas escapes slowly, the substrate tends to momentarily float above the susceptor and drift from the center. Thus, the substrate may not be centered in the pocket as normally intended, potentially resulting in uneven heating of the substrate. This drift of the substrate to the edge of the susceptor can result in poor thickness uniformity, poor resistivity uniformity, and crystallographic slippage, depending on the nature of the layer being deposited.

[0014] In some embodiments, multiple protrusions (e.g., pins, prongs, etc.) can lift the substrate from the susceptor to facilitate transfer to or from the susceptor by the effector. During substrate removal, "sticking" can occur when the substrate adheres to the underlying support due to slow gas flow into the small space between the substrate and the surface of the substrate support pocket. This creates a vacuum effect between the substrate and the substrate support as the substrate is lifted. Sticking can cause particle contamination due to scratches on the substrate support, and in extreme cases, can lift the substrate holder by as much as 1-2 mm.

[0015] Substrate "curl" is the bowing of the substrate caused by radial and axial temperature gradients across the substrate. Severe curl can cause portions of the substrate to contact the bottom side of a Bernoulli wand, for example, when a cold substrate is first lowered onto a hot substrate support, such as a susceptor. Curl can similarly affect interactions with other robotic substrate handling devices. In the case of a Bernoulli wand, the top surface of the substrate can scratch the Bernoulli wand and cause particulate contamination on the substrate. This can significantly reduce yield.

[0016] Susceptors can be equipped with flow channels or perforation designs to reduce sliding, sticking, curling, backside deposition, and other substrate processing quality issues. For example, the top surface of a susceptor can be equipped with channels that allow flow approximately horizontally along the top surface to reduce these issues. However, susceptors with radially channeled grid designs can still cause backside damage on substrates. Perforated susceptors can be equipped with separate vent channels that allow flow (e.g., vertically) across the top surface of the susceptor to prevent such damage. Nevertheless, backside deposition can still occur on perforated substrates with such vents in some susceptors. Furthermore, the vents may be in an unfavorable location or may not be compatible with grid or other channel structures that allow gas access to the backside of the susceptor. As described in more detail below, horizontal channel embodiments with improved venting and / or reduced substrate sticking may be a solution to these issues. Some embodiments can also provide aesthetically pleasing benefits.

[0017] Referring now to the figures, Figure 1 schematically illustrates an embodiment of a semiconductor processing apparatus 100 comprising a reaction chamber 101 and a loading chamber 102. The reaction chamber 101 and the loading chamber 102 together may be considered process modules implemented, for example, in a multi-module "cluster" tool. In the illustrated embodiment, the reaction chamber 101 is positioned above the loading chamber 102, which are separated by a base plate 107 and a movable pedestal or workpiece support 109, as described in more detail below. The workpiece support 109 may comprise a susceptor, as used elsewhere herein.

[0018] In some embodiments, the reaction chamber 101 may be substantially smaller than the loading chamber 102, as shown in the schematic diagram, which is not drawn to scale. For a single-wafer module, the reaction chamber 101 may have a volume of approximately 0.25 liters to 3 liters. In some embodiments, the reaction chamber 101 may have a volume of less than approximately 1 liter. In some embodiments, the reaction chamber 101 may be approximately 900 mm long, 600 mm wide, and 5 mm high. In some embodiments, the loading chamber 102 may have a volume of approximately 30 liters to approximately 50 liters. In some embodiments, the loading chamber 102 may have a capacity of approximately 40 liters. In some embodiments, the loading chamber 102 may have a volume that is approximately 35-45 times the volume of the reaction chamber 101.

[0019] In some embodiments, the reaction chamber 101 can include one or more inlets 103 (one shown) and one or more outlets 104 (one shown). During processing, gases, such as reactants and purge gases, can flow into the reaction chamber 101 through the reaction chamber inlet 103, and gases, such as excess reactants, reactant by-products, and purge gases, can flow out of the reaction chamber 101 through the reaction chamber outlet 104. In some embodiments, the loading chamber 102 can include one or more inlets 105 (one shown) and one or more outlets 106 (one shown). During operation, gases, such as purge gases, can flow into the loading chamber 102 through the loading chamber inlet 105, and gases, such as excess reactants, reactant by-products, and purge gases, can flow out of the loading chamber 102 through the loading chamber outlet 106. The illustrated configuration, e.g., the locations of the inlets 103, 105 and outlets 104, 106, are merely schematic and can be adjusted based on, for example, the process being performed in the reaction chamber 101, the desired flow path of the gases, etc. The purge gas can include a single purge gas or a mixture of purge gases. For example, in some embodiments, the purge gas can consist essentially of one or more inert gases, e.g., one or more noble gases (e.g., helium, argon, neon, xenon, etc.). The purge gas can include one or more inert gases that do not include any reactive gases. In other embodiments, the purge gas can include, for example, one or more inert gases and one or more other non-inert gases. The purge gas can include an inert gas mixed with a reactive gas, e.g., hydrogen. The purge gas can include, for example, a mixture of hydrogen and argon. In some embodiments, a first purge gas consisting essentially of one or more inert gases (i.e., not including any reactive gases) can be used in the first purge step, and a second purge gas comprising a mixture of one or more inert gases mixed with one or more reactive gases can be used in the second purge step.In some embodiments, this second purge step follows the first purge step consecutively. Using a purge step including one or more inert gases with one or more reactive gases can help improve the distribution of reactants across the substrate. For example, a delivery system (e.g., a shower or showerhead) can generally concentrate the reactants near the center of the substrate. The delivery system can flow gas substantially perpendicular to the surface of the substrate. During the second purge step, a mixture of inert and reactive gases can provide better distribution of reactants, for example, near the edge of the substrate. In some embodiments, a gas, such as a purge gas, can flow through, into, and / or along a portion of the workpiece support 109. Such an embodiment can provide purge gas along the backside of a substrate disposed on the support 109 to prevent backside substrate deposition.

[0020] In the illustrated embodiment, the reaction chamber 101 includes a base plate 107 with an opening 108. An inner edge of the base plate 107 defines the opening 108. In some embodiments, the base plate 107 can include titanium. In the illustrated embodiment, the reaction chamber inlet 103 is positioned generally opposite the reaction chamber outlet 104, so that reactive gases flowing from the reaction chamber inlet 103 to the reaction chamber outlet 104 travel generally parallel to the plane of the workpiece W and, therefore, parallel to the upper surface of the movable support. Such a reactor may be referred to as a "crossflow" or horizontal laminar flow reactor. In some embodiments, the reaction chamber 101 can include an inlet or multiple inlets, such as a showerhead positioned above the susceptor to form a vertical flow reactor, or a "showerhead" reactor that supplies reactants oriented perpendicular to the upper surface of the substrate. For example, as shown, the top wall of the chamber 101 can be configured as a showerhead or can include a showerhead attached thereto. An example of a showerhead implemented within a reaction chamber is described in U.S. Patent Application Publication No. 2019 / 0139807, the entire disclosure of which is incorporated herein by reference for all purposes.

[0021] In some embodiments, the apparatus 100 may be an atomic layer deposition (ALD) reactor and may include valves controlled by a control system 113 to separately provide pulses of reactants. In some embodiments, the apparatus 100 may include two or more valves controlled independently of each other by the control system 113 to adjust the relative pressure and / or flow direction between the reaction chamber 101 and the loading chamber 102. In some embodiments, the reaction chamber inlet 103 may include a distribution system to distribute gas in a desired pattern. In some embodiments, the reaction chamber 101 may taper near the reaction chamber outlet 104 such that the height of the reaction chamber 101 decreases near the reaction chamber outlet 104, thereby restricting airflow through the reaction chamber outlet 104. While the apparatus 100 may be described herein with respect to a deposition (e.g., chemical vapor deposition, or CVD, and / or atomic layer deposition, or ALD) reactor, the apparatus 100 may alternatively include other semiconductor processing tools, including, but not limited to, dry etchers, ashers, rapid thermal annealers, etc.

[0022] The apparatus 100 further includes a movable support 109 configured to move between a loading position and a processing position by operation of a drive mechanism 110. FIG. 1 shows the support 109 in a loading position according to one embodiment. The support 109 can be configured to hold a workpiece (semiconductor workpiece W, see FIG. 2 ), such as a silicon wafer. The workpiece W can be loaded and removed from the support 109 in various ways, for example, using a robot end effector. The support 109 can include lift pins 111 and / or notches to assist in loading and removing the workpiece W using a paddle or fork. The support 109 can include a vacuum system to hold the workpiece W in place after loading, or it can rely solely on gravity to hold the workpiece W in a pocket sized and shaped to correspond to the workpiece W. The apparatus 100 can further include one or more gate valves 112 (one shown) for loading and removing the workpiece W from the support 109. Gate valves 112 may allow access to, for example, a transfer chamber, a load lock, a processing chamber, a clean room, and the like.

[0023] The control system 113 is also configured or programmed to control the drive mechanism 110. In some embodiments, the drive mechanism 110 can comprise a piston or elevator that imparts vertical movement to the support 109. The drive mechanism 110 is thus configured to move the support 109, and thus the workpiece W disposed on the support 109, to a processing position during a reactor closing operation and to a loading position during a reactor opening operation. The drive mechanism 110 can also be configured to rotate the workpiece W disposed on the support 109.

[0024] FIG. 2 schematically illustrates the apparatus 100 with the support 109 shown in the processing position, according to one embodiment. When the support 109 is in the processing position, it engages with the base plate 107, effectively isolating or separating the interior of the reaction chamber 101 from the loading chamber 102. Such separation can reduce contamination between the reaction chamber 101 and the loading chamber 102. In some embodiments, the engagement can include forming a hard metal-to-metal seal between the base plate 107 and the support 109. In some embodiments, the engagement can include compressing a flexible material, such as an O-ring, in either portion to form a soft seal between the base plate 107 and the support 109. In some embodiments, the engagement can include maintaining a gap between the support 109 and the base plate 107 to prevent a complete seal. Even when the engagement includes maintaining a gap between the support 109 and the base plate 107, the support can further effectively separate the reaction chamber 101 from the loading chamber 102 by forming a substantial barrier to fluid communication between the reaction chamber 101 and the loading chamber 102 when the apparatus 100 is in the processing position.

[0025] FIG. 3 illustrates a fluid volume of an exemplary susceptor 200 that can be used to support a substrate (e.g., a wafer). The susceptor 200 can include an outer rim 208 that forms a periphery around the surface 204. The surface 204 can include a channel region 212 located outward from an inner region 214. The surface 204 can further include one or more channels 220. The susceptor 200 can be composed of one or more materials, such as elemental or molecular materials. Such materials can include non-oxide ceramics, such as silicon carbide (SiC or CSi), graphite, or any other ceramic. Other materials, such as metals, can also be used. In some embodiments, the susceptor 200 can include a silicon carbide coating, such as silicon carbide-coated graphite. The surface 204 can be configured to hold or support a substrate (not shown).

[0026] The rim region 217 can be located radially outward from the channel region and can provide additional structural integrity and / or easier access to portions of the susceptor 200, if desired. The rim region 217 can be bounded between the edge 208 and the outer radial boundary of the channel region 212. In some embodiments, the function of the rim region 217 can be performed by the base plate 107 of FIG. 2. The channel region 212 can be bounded by an outer rim 216 and an inner boundary, such as an inner rim 232 or inner channel ring. Any "boundary" described herein may be a subtle difference in rise angle, material, bow / dimple, smoothness, and / or other differences between adjacent regions. The rim region 217 may be substantially flat and / or smooth. For example, the rim region 217 may be substantially free of channels, protrusions, holes, and / or other irregularities in the surface of the rim region 217. The rim region 217 may have a radial width (defined as the radial distance between the edge 208 and the outer radial boundary) of approximately 15 mm to 35 mm.

[0027] The channel region 212 can be located between the outer rim 216 and the inner rim 232. One or both of the outer rim 216 and / or inner rim 232 can be circular, e.g., substantially circular or other rounded shape (e.g., oval). The inner region 214 can be substantially flat and / or smooth. For example, the inner region 214 can be substantially free of channels, protrusions, and / or other irregularities. The inner region 214 can be shaped and / or sized to further structurally integrate the susceptor 200. For example, including irregularities within the inner region 214 can reduce the strength of the inner region 214. In some embodiments, the inner region 214 is recessed relative to the surrounding channel region 212.

[0028] The channel region 212 may be disposed adjacent to and / or radially inward of the rim region 217. The channel region 212 may be disposed between the rim region 217 and the inner region 214. Within the channel region 212, one or more channels 220 may be formed in the face 204, and for convenience, a plurality of channels 220 will be referred to throughout. The channels 220 may extend radially outward from or near the center of the face 204 toward the edge 208 (in some embodiments, toward and through the edge 208). In some embodiments, the channels 220 may extend from at or near the inner rim 232 to at or near the outer rim 216. In some embodiments, the channels 220 may extend substantially radially from the center of the face 204 and / or toward and through the edge 208. In some embodiments, consecutive channels 220 may form an angular separation or angle 240. Consecutive channels may also be referred to as "adjacent" or "adjacent." The angle 240 may be an acute angle. For example, the angle 240 may be between about 5° and 35°, and in some embodiments, about 15° between at least two consecutive channels 220. Consecutive channels 220 may also be referred to herein as consecutive or adjacent channels 220. A plurality of regularly spaced consecutive channels 220 may have substantially the same angle 240 between each set of consecutive channels 220. As shown, the surface 204 may comprise multiple sets of such a plurality of consecutive channels 220. The regularity of the angle 240 may be disrupted, for example, by one or more irregularities in the channel region 212. For example, as shown, one or more openings 256 and / or raised features 234 (shown in FIG. 4A ) may be included in the channel region. The openings 256 may be configured to allow a laser (e.g., a pin, protrusion, rod, etc.) to pass therethrough. A susceptor support device (eg, spider) (not shown) can use a raiser to lift the wafer from the susceptor 200 without lifting the susceptor 200 itself.Thus, the angle 240 between successive channels 220 where irregularities may be found may be larger, such as twice the above angle 240. Such increased angular separation may allow those portions of the susceptor with openings 256 to have additional structural integration and / or may provide additional space to avoid interference with lasers and susceptor support equipment.

[0029] The channel region 212 may form a "pocket" or recess in which a substrate can rest. An outer rim 216 or other outer boundary may form the outer boundary of this pocket. The channel region 212 may have a slope and / or a concave surface that forms a raised portion relative to the inner region 214 to limit the amount of substrate (e.g., the edge or rim of the substrate) contacting the susceptor 200. A majority of the surface area of ​​the channel region 212 may be substantially flat and / or smooth. One or more portions of the channel region disposed between consecutive channels 220 may have an increasing area moving from the inner rim 232 to the outer rim 216. One or more channels 220 may be substantially straight. The number of channels 220 in a channel region may be about 3 to 72, or about 18 to 30, although other variations are possible. In some embodiments, the number of channels is 36.

[0030] The channel region 212 may be tapered, disposed at a slight incline, such that the substrate rests only on a portion of the channel region 212. The rise angle of the channel region 212 relative to the back surface 206 may be between about 0.5° and 5°, and in some embodiments, is about 3°. The rise angle may be an absolute value (e.g., when the inner channel region 124 is substantially flat). In some embodiments, the cross-sectional shape of the channel region 212 (e.g., the cross-section shown in FIG. 3) may form a recess, e.g., a concave shape. Thus, the channel region 212 may be configured to support the edge of the substrate, thereby reducing substrate contact with the susceptor 200.

[0031] The susceptor may be surface treated to improve performance. For example, one or more areas of surface 204 may be polished to reduce the likelihood of deformation affecting the substrate (e.g., caused by substrate adhesion). Portions of susceptor 200 may be coated to improve performance. For example, surface 204 may be coated with silicon carbide.

[0032] FIG. 3 also illustrates how each of the channels 220 can include a corresponding elongated portion 224 and a flush-out portion 228. The width and / or cross-sectional area of ​​each of the elongated portions 224 can be substantially constant along the radial length of the elongated portion 224. Each elongated portion 224 can have a width equal to or less than a threshold width along the entire elongated channel portion. The threshold width can be about 0.01 mm, about 0.05 mm, about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.5 mm, about 0.7 mm, about 0.9 mm, about 1 mm, about 1.2 mm, about 1.5 mm, about 1.8 mm, about 2 mm, about 2.5 mm, about 3 mm, about 4 mm, about 5 mm, about 7 mm, about 10 mm, about 15 mm, about 20 mm, any value therein, or can be within a range having endpoints therein. The cross-sectional area of ​​the elongated portion can be substantially constant along the radial length of the elongated portion 224. For example, the cross-sectional area may be within a threshold width (e.g., greater than or less than) a threshold, e.g., a percentage above the threshold, which may be about 1%, about 3%, about 5%, about 10%, about 15%, about 20%, about 25%, or other percentage.

[0033] One or more channels 220 may include a respective flush-out section 228. The flush-out section 228 may be in fluid communication with the elongated portion 224. Further details of the flush-out section 228 are provided below with reference to FIG. 5 . In some embodiments, the flush-out section 228 is disposed radially outward of the elongated portion 224. The flush-out section 228 may be triangular (e.g., pie-shaped). The distal ends of the channels 220 (e.g., the distal ends of the flush-out sections 228 and the portions of the faces therebetween) may form a purge perimeter 226. The substrate may be supported on the purge perimeter 226, and during purging, purge gas flows around the purge perimeter and the edges of the substrate to prevent backside deposition. The flush-out section 228 increases flow uniformity (e.g., velocity and / or pressure uniformity) around the purge perimeter 226, improving yield and reducing backside deposition.

[0034] The continuous elongated portions 224 may form an angle 290 therebetween. In some embodiments, the elongated portions 224 may be at an acute angle. The elongated portions 224 may be at an angle of about 10°, about 15°, about 18°, about 20°, about 22°, about 25°, about 27°, about 30°, about 32°, about 33°, about 35°, about 40°, about 42°, about 45°, about 50°, about 55°, about 60°, about 65°, about 70°, about 75°, about 80°, about 90°, about 100°, about 110°, about 120°, about 180°, any value therein, or within a range having an endpoint therein. The quantity of channels 220, the angle 290 therebetween, the width of the channels, and / or the cross-sectional shape and area of ​​the channels 220 can be selected within a range that improves the uniformity of heat transfer within the susceptor.

[0035] FIG. 4A illustrates another example susceptor 200 according to some embodiments. The susceptor 200 illustrated in FIG. 4A exhibits multiple protrusions 234 and openings 256. The protrusions 234 extend upward relative to a peripheral portion of the front surface 204, providing a small distance between the substrate and the peripheral portion of the front surface 204. This distance can improve the functionality and effectiveness of any applied or inherent vacuum. The protrusions 234 can help reduce adhesion of the substrate to the susceptor 200 and / or reduce direct contact with the backside of the substrate, thereby reducing the possibility of contamination or damage to the substrate. The protrusions 234 can also improve the uniformity of heat transfer to the substrate.

[0036] As shown in FIG. 4A , one or more openings 256 may be provided within the susceptor 200. The openings 256 may be lift pin holes that allow lift pins to extend through the susceptor 200. The openings 256 may allow a substrate (e.g., a wafer) to be placed on and / or removed from the surface 204. The openings 256 may be located radially inward of the outer boundary of the susceptor 200 (e.g., the outer rim 216, edge 208, etc., shown in FIG. 3 ). In some embodiments, the openings 256 are located radially outward from the outer boundary. In some embodiments, there are three lift openings 256, although other numbers are possible. The openings 256 may extend between the front and back surfaces and may be configured to allow pins to extend therethrough. The openings 256 may be located between successive elongated portions of the multiple channels. The angular separation between each radially successive opening may be substantially equal. For example, the angular separation between successive openings with three openings may be approximately 120°. Other variations are possible. The inner diameter of each of the openings 256 may be between about 35 mm and 400 mm, and in some embodiments is about 160 mm. Figure 4B shows a perspective view of the back surface 206 of the susceptor 200 shown in Figure 4A. As shown, the openings 256 may extend all the way through the back surface 206.

[0037] FIG. 5 shows a detailed view of a portion of the susceptor 200 shown in FIG. 4A . The channels 220 in the face 204 of the susceptor 200 may extend radially outward from an inner rim 232. In some embodiments, the channels 220 may extend from an inner radial boundary, such as a ring channel 230 or inner rim 232. The ring channel 230 may extend into the face 204 and be disposed radially inward of the channels 220 and in fluid communication with at least one of the plurality of channels 220. The ring channel 230 may receive a gas (e.g., a purge gas) through an opening 235 to form a volume configured to provide better pressure uniformity in the gas supply flow to the plurality of channels 220. The channels 220 may extend substantially radially from the ring channel 230. In some embodiments, the continuous channels 220 may form an angle 240, as shown. The angle 240 may form an acute angle. For example, the angle 240 may be approximately 3° to 30°, and in some embodiments, approximately 7.5° between at least two consecutive channels 220. Consecutive channels 220 may also be referred to herein as consecutive or adjacent channels 220. A plurality of regularly spaced consecutive channels 220 may have substantially the same angle 240 between each set of consecutive channels 220. Although not shown, the surface 204 may comprise multiple sets of such consecutive channels 220. The regularity of the angle 240 may be disrupted, for example, by one or more irregularities in the surface 204. For example, one or more openings 256 may be provided in the channel region. Thus, the angle 240 between consecutive channels 220 where irregularities may be found may be larger, such as twice the angle 240 described above. Such increased angular separation may allow for additional structural integration and / or provide additional space to avoid interference with laser and susceptor support devices.The two continuous elongated portions 224a, 224b of the plurality of channels can form an angle 240 of about 1°, about 2°, about 3°, about 5°, about 7°, about 10°, about 12°, about 15°, about 18°, about 20°, about 22°, about 25°, about 28°, about 30°, about 33°, about 35°, about 40°, about 45°, any angle therein, or can be within a range having an endpoint therein.

[0038] The continuous flash-out portions 228a, 228b can additionally or alternatively form various angles. As shown, the first channel can include a first flash-out portion 228a having a first edge 276 and a second edge 280. The first edge 276 and the second edge 280 can form an angle 290. The angle 290 can be about 1°, about 2°, about 3°, about 5°, about 7°, about 10°, about 12°, about 15°, about 18°, about 20°, about 22°, about 25°, about 28°, about 30°, about 33°, about 35°, about 40°, about 45°, any angle therein, or can be within a range having an endpoint therein. As shown, the first edge 276 and the second edge 280 do not need to meet to form the angle 290.

[0039] The second flash-out portion 228b can include a corresponding first edge 284 and second edge 288. The second edge 280 of the first flash-out portion 228a can form an angle 272 with the first edge 284 of the second flash-out portion 228b. The angle 272 can be about 1°, about 2°, about 3°, about 5°, about 7°, about 10°, about 12°, about 15°, about 18°, about 20°, about 22°, about 25°, about 28°, about 30°, about 33°, about 35°, about 40°, about 45°, any angle therein, or can be within a range having an endpoint therein. As shown, the second edge 280 and the first edge 284 do not have to meet to form the angle 290. For example, a substantially planar connector can connect the second edge 280 and the first edge 284.

[0040] FIG. 6 shows a cross-sectional view of an exemplary channel 220. Other cross-sectional shapes are possible. As shown, the channel 220 can have curved sidewalls. The sidewalls may form a substantially semicircular shape along the cross-section. The radius of curvature 288 can be between about 0.1 mm and 2.5 mm, and in some embodiments, is about 0.6 mm. The curved sidewalls shown can help prevent gas buildup during deposition. The width 264 of the channel 220 can be between about 0.1 mm and 5 mm, and in some embodiments, is about 1.2 mm. The depth 266 of the channel 220 can be between about 0.05 mm and 1.5 mm, and in some embodiments, is about 0.6 mm. In some embodiments, the channel 220 can have substantially flat sidewalls. The sidewalls may form an angle, such as an acute angle.

[0041] 7A, 7B, and 7C show various perspective views of vector map simulations illustrating the magnitude and direction of gas flow velocity through the channels. FIG. 7B shows higher velocities of gas particles immediately after exiting the elongated section of the corresponding channel. Beyond the outlet of the elongated section, the velocity decreases and further decreases within the flush-out section as the width and cross-sectional area expand. This allows the velocity of gas particles to be substantially uniform around the purge perimeter (e.g., purge perimeter 226) formed by the distal ends of the multiple channels at the outlet of the flush-out section. The term "substantially uniform" can include generating respective velocities for at least a certain percentage (e.g., 50%, 75%, 80%, 90%, 95%, etc.) of the gas particles that do not vary by more than a standard deviation from the average velocity of the gas particles.

[0042] Figures 7A-7C and 8 show perspective views of vector maps illustrating the magnitude and direction of gas flow through the channels. Figure 8 shows similar results to Figures 7A-7C, but for pressure. In essence, Figure 8 shows a higher magnitude of gas particle pressure immediately after exiting the elongated section of the corresponding channel, which then decreases and propagates through the flush-out section. As the width and cross-sectional area increase, the pressure within the flush-out section further decreases. This allows the gas pressure to be substantially uniform around the purge perimeter formed by the distal ends of the multiple channels at the outlet of the flush-out section. The term "substantially uniform" can include generating respective pressures for at least a certain percentage (e.g., 50%, 75%, 80%, 90%, 95%, etc.) of gas particles that do not vary by more than a standard deviation from the average velocity of the gas particles. Figures 7A-8 show how susceptor configurations with channel embodiments herein can improve flow uniformity, including pressure and velocity, around the perimeter of a substrate supported on the susceptor. This improved uniformity of flow can in turn reduce backside deposition on the susceptor, improving substrate yield and reducing substrate waste.

[0043] The present aspects and embodiments may be described in terms of functional block components and various process steps. Such functional blocks may be implemented by various hardware or software components configured to perform the specified functions and achieve various results. For example, the present aspects may use various sensors, detectors, flow controllers, heaters, etc., capable of performing various functions. Furthermore, the present aspects and embodiments may be practiced with any number of process methods, and the described devices and systems may use a variety of process methods, and the described devices and systems are merely examples of applications of the invention. [Explanation of symbols]

[0044] 100 Semiconductor processing equipment 101 Reaction Chamber 102 Loading chamber 103 Reaction chamber entrance 104 Reaction chamber outlet 105 Entrance to loading chamber 106 Outlet of loading chamber 107 Base Plate 108 Reaction chamber opening 109 Workpiece support 110 Drive mechanism 111 Lift Pin 112 Gate valve 113 Control System 200 susceptor 204 sides 206 Back side 208 Outer Edge 212 channel region 214 Inner area 216 outer rim 217 Rim Area 220 channels 224, 224a, 224b Long and thin 226 Purge Surroundings 228, 228a, 228b Flash-out section 230 Ring Channel 232 inner rim 234 Raised features, protrusions 240 angle 256 openings 266 Channel Depth 272 angle 276 First Edge 280 Second Edge 284 First Edge 288 Second Edge 290 angle

Claims

1. A susceptor, a surface configured to support a substrate thereon; a plurality of channels extending within the surface and radially outward relative to a center of the surface, each of the plurality of channels comprising: a strip having a width along the entire strip that is less than or equal to a threshold width; a plurality of channels comprising: a flush-out portion in fluid communication with the elongated portion, the flush-out portion comprising a first portion having a first width and a second portion having a second width greater than the first width, the first portion being disposed radially inward of the second portion; The flash-out portion is defined by a region surrounded by a first edge, a second edge, and an outer edge of the susceptor.

2. The susceptor of claim 1 , wherein the second width of the second portion extends along a perimeter formed by the plurality of channels.

3. The susceptor of any one of claims 1 to 2, wherein the width of the elongated portion is substantially constant along the radial length of the elongated portion.

4. 4. The susceptor of claim 1, wherein the flush-out portion has a radial length and a radial width such that a ratio of the radial length to the radial width is from about 0.6 to about 1.

4.

5. The susceptor according to any one of claims 1 to 4, wherein the flush-out portion is triangular.

6. A susceptor described in any one of claims 1 to 5, wherein the first edge is oriented relative to the second edge at an angle of approximately 25° to 110°.

7. 7. The susceptor of claim 6, wherein the plurality of channels comprises a first channel and a second channel continuous with the first channel, and the first edge of the second channel and the second edge of the first channel are disposed at an angle of about 15° to 100° therebetween.

8. 7. The susceptor of claim 6, wherein the plurality of channels comprises a first channel and a second channel continuous with the first channel, and the angle between the first edge and the second edge of the flash-out portion of the first channel is different from the angle between the first edge and the second edge of the flash-out portion of the second channel.

9. The susceptor of any one of claims 1 to 8, wherein the elongated portion has a depth of about 0.05 mm to 1.5 mm.

10. The susceptor of any one of claims 1 to 9, wherein the plurality of channels comprises about 18 to 45 channels.

11. The susceptor of any one of claims 1 to 10, wherein two consecutive elongated portions of the plurality of channels form an angle of about 3° to 25°.

12. a back surface opposite to the surface; 12. The susceptor of claim 1, further comprising one or more openings extending between the face and the back surface, the one or more openings configured to allow pins to extend therethrough to lift a substrate from the face of the susceptor.

13. The susceptor of claim 12 , wherein the one or more openings are disposed between the elongated portion and a continuous elongated portion of a second channel of the plurality of channels.

14. 14. The susceptor of claim 12 or 13, wherein the one or more openings comprise at least three openings, and wherein the angular separation between each radially consecutive opening of the at least three openings is substantially equal.

15. The cross section of the elongated portion is 15. The susceptor of claim 1, comprising first and second sidewalls, each of the first and second sidewalls being substantially flat, and the first and second sidewalls being disposed at an acute angle relative to one another.

16. The susceptor of any one of claims 1 to 15, further comprising a ring channel extending in said face and positioned radially inward of and in fluid communication with at least one of said plurality of channels.

17. A susceptor, a surface configured to support a substrate thereon; a plurality of channels extending within the face and radially outward relative to a center of the face, each of the plurality of channels having a distal end, the distal ends of the plurality of channels forming a purge perimeter, the plurality of channels configured to generate at least one of a substantially uniform velocity and pressure of gas around the purge perimeter while gas flows radially through the channels; The susceptor, wherein the plurality of channels are configured to maintain at least one of a substantially uniform gas velocity and pressure around the purge perimeter for at least 75% of the gas particles at a velocity that does not vary by more than a standard deviation from the average velocity of all the gas particles.

18. A reaction chamber comprising the susceptor of any one of claims 1 to 17, further comprising a showerhead configured to direct a flow of gas substantially perpendicular to the surface.

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