Wafer bearing mechanism and epitaxial device

Abstract

The utility model belongs to the technical field of CVD (Chemical Vapor Deposition) equipment, and discloses a wafer bearing mechanism and an epitaxial device, the wafer bearing mechanism comprises a base assembly and a bearing assembly, the base assembly comprises a base body, the base body is provided with a bearing ring and a rotating shaft, the rotating shaft and the bearing ring are located on two opposite sides of the base body, and the bearing assembly is arranged on the bearing ring. Bearing blocks are arranged on the inner ring of the bearing ring in the circumferential direction at intervals, and a through opening is formed between every two adjacent bearing blocks; a bearing groove is formed in the side, facing the base body, of the bearing block. The supporting assembly comprises a tray ring, and the tray ring is configured to support a wafer; supporting lugs are distributed on the tray ring in the circumferential direction of the tray ring and can be embedded into the bearing grooves through the through openings. The epitaxial device comprises the wafer bearing mechanism, so that the stability of the wafer during reaction can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to CVD equipment technical field especially relates to a wafer bearing mechanism and epitaxial device. BACKGROUND

[0002] Silicon carbide (hereinafter referred to as SiC) as the typical representative of the third generation semiconductor material, has wide band gap, high breakdown field, high thermal conductivity, high electron saturation rate and strong radiation resistance and other characteristics, therefore in high temperature, high pressure and high frequency field shows the wide application prospect;

[0003] At present, SiC epitaxial method mainly has chemical gas phase epitaxy (CVD) and liquid phase epitaxial growth (LPE) etc., and the deposition thickness and the uniformity of the doping concentration of epitaxial wafer are the key parameters influencing the performance of silicon carbide device, and the depletion mode of growth source and doping source along the airflow direction is close to linear depletion, which is the fundamental reason leading to the non-uniformity of the deposition thickness and the concentration of epitaxial wafer;

[0004] Based on the above reasons, the prior art can greatly reduce the thickness and doping concentration non-uniformity by rotating the base to drive the rotation of the epitaxial wafer (wafer);The existing technology has appeared the wafer bearing mechanism of inverted hanging setting, so that the wafer is downward for reaction, and the wafer bearing mechanism is easy to cause poor stability when rotating, which affects the reaction effect. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a wafer bearing mechanism and epitaxial device, and improving the stability of wafer reaction.

[0006] In order to achieve this purpose, the utility model adopts the following technical scheme:

[0007] The wafer bearing mechanism comprises:

[0008] The base assembly comprises a base body, a bearing ring and a rotating shaft are arranged on the base body, the rotating shaft and the bearing ring are located on the opposite sides of the base body, the inner ring of the bearing ring is circumferentially spaced apart from the supporting block, and the through opening is formed between the adjacent supporting blocks;The side of the supporting block facing the base body is provided with a supporting groove;

[0009] The supporting assembly comprises a tray ring, and the tray ring is configured to support the wafer;The tray ring is circumferentially distributed with a supporting lug corresponding to the through opening, the supporting lug can pass through the through opening, and can be embedded into the supporting groove.

[0010] In some embodiments, the supporting assembly further comprises a pressing plate, and the pressing plate is used to press the wafer on the tray ring.

[0011] In some embodiments, the tray ring comprises a first ring holder and a second ring holder, the second ring holder is supported on the first ring holder, the wafer is supported on the second ring holder, and the lug is disposed on the first ring holder; the first ring holder is made of silicon carbide, and the second ring holder is made of graphite.

[0012] In some embodiments, the tray ring is provided with a plurality of abutting positions.

[0013] In some embodiments, the rotating shaft comprises a shaft rod and a shaft sleeve, the shaft sleeve comprises a plurality of first arc-shaped plates circumferentially and spacedly disposed on the base body, and the outer side of the first arc-shaped plate is provided with a first thread; the shaft rod comprises a rod body, the outer periphery of the rod body is provided with a plurality of second arc-shaped plates circumferentially and spacedly disposed, and the outer side of the second arc-shaped plate is provided with a second thread; when the rod body is inserted into the space enclosed by the first arc-shaped plates, the second arc-shaped plates are inserted between adjacent first arc-shaped plates, the second thread and the first thread are combined into an external thread, and the wafer carrying mechanism further comprises a locking sleeve provided with an internal thread, and the locking sleeve is locked on the first arc-shaped plates and the second arc-shaped plates.

[0014] An epitaxial device is also provided, which comprises a furnace body, a wafer carrying mechanism as described above, and a heater, the furnace body has an inner cavity, the wafer carrying mechanism is disposed in the inner cavity, and the heater is disposed on the side of the base body away from the supporting block and used for heating the wafer.

[0015] In some embodiments, the heater is fixed to the cavity wall of the inner cavity, the heater is provided with a through hole, and the rotating shaft penetrates through the heater.

[0016] In some embodiments, the epitaxial device further comprises a sleeve and a low thermal conductor, the sleeve and the low thermal conductor are both fixed to the cavity wall of the inner cavity, the sleeve surrounds the outer periphery of the base body, the low thermal conductor is located in the sleeve, and the low thermal conductor is provided with a through hole for the rotating shaft to penetrate.

[0017] In some embodiments, a flow channel is formed between the sleeve and the base body to enable the flow of purge gas around the outer periphery of the base body, and the low thermal conductor and / or the sleeve is provided with an air inlet channel communicating with the flow channel.

[0018] In some embodiments, the sleeve is circumferentially provided with a first ring plate, the outer periphery of the base body is circumferentially provided with a second ring plate, and when the base body is placed in the inner ring of the first ring plate, the first ring plate and the second ring plate are spacedly arranged above and below to form the flow channel.

[0019] In some embodiments, the first ring plate and the second ring plate are provided with protrusions, the protrusions of the first ring plate extend towards the second ring plate, the protrusions of the second ring plate extend towards the first ring plate, and the protrusions of the first ring plate and the protrusions of the second ring plate are arranged in a staggered manner.

[0020] The wafer supporting mechanism has the advantages that:

[0021] The wafer is placed on the supporting ring, the supporting ears on the supporting ring are inserted into the through opening, then the supporting ring is rotated, the supporting ears of the supporting ring are inserted into the supporting grooves for limiting, then the base body is driven to rotate by the rotating shaft, and the wafer is rotated; in the rotating process, the supporting ears are always inserted into the supporting grooves, so that the stability of wafer rotation is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is an explosion view of the wafer supporting mechanism of the utility model;

[0023] Figure 2 is a schematic view of the base body showing the supporting grooves of the utility model;

[0024] Figure 3 is an explosion view of the supporting assembly in the utility model;

[0025] Figure 4 is a sectional view of the base assembly fixing the wafer in the utility model;

[0026] Figure 5 is a schematic view of the wafer supporting mechanism provided with the sleeve and the low-thermal-conductivity body in the utility model;

[0027] Figure 6 is Figure 5 an enlarged view of A in the utility model;

[0028] Figure 7 is a schematic view of the sleeve and the low-thermal-conductivity body in the utility model.

[0029] In the drawings:

[0030] 10, wafer supporting mechanism;

[0031] 1, base assembly; 11, base body; 12, supporting ring; 13, rotating shaft; 131, rod body; 132, first arc-shaped plate; 133, second arc-shaped plate; 14, second ring plate; 15, supporting block; 16, supporting groove; 17, limiting table; 18, through opening;

[0032] 2, supporting assembly; 21, supporting ring; 211, first ring supporting part; 212, second ring supporting part; 213, supporting ear; 214, abutting position; 22, pressing plate;

[0033] 3, heater; 31, through hole;

[0034] 4, locking sleeve;

[0035] 5, flow channel;

[0036] 20, sleeve; 201, first ring plate; 202, protrusion;

[0037] 30, low thermal conductor; 301, perforation;

[0038] 40, wafer. DETAILED DESCRIPTION

[0039] The utility model will be described in further detail below in combination with the drawings and examples. It can be understood that the specific examples described here are only used to explain the utility model, and not to limit the utility model. In addition, it should be noted that only the parts related to the utility model are shown in the drawings for ease of description, not all the structures.

[0040] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0041] In the utility model, unless otherwise explicitly specified and limited, the first feature "on" or "below" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0042] In the description of the embodiment, the terms "up", "down", "left", "right" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation of the utility model. In addition, the terms "first" and "second" are only used to distinguish in description, and have no special meaning.

[0043] As Figures 1 to 7 shown, the application provides a wafer carrying mechanism, which comprises a base assembly 1 and a supporting assembly 2, the base assembly 1 comprises a base body 11, the base body 11 is provided with a carrying ring 12 and a rotating shaft 13, the rotating shaft 13 and the carrying ring 12 are located on opposite sides of the base body 11, the inner ring of the carrying ring 12 is circumferentially spaced to form a through port 18 between adjacent supporting blocks 15; the side of the supporting block 15 facing the base body 11 is provided with a supporting groove 16; the supporting assembly 2 comprises a tray ring 21, which is configured to support a wafer 40; the tray ring 21 is circumferentially distributed with a supporting lug 213 corresponding to the through port 18, the supporting lug 213 can be moved from one side of the supporting block 15 to the other side through the through port 18, and embedded into the supporting groove 16 by rotating.

[0044] The wafer 40 is placed on the tray ring 21 for supporting, the tray ring 21 is held by an external mechanical hand, the supporting lug 213 on the tray ring 21 is moved from one side of the supporting block 15 to the other side through the through port 18 (that is, from the side of the supporting block 15 away from the base body 11 to the side facing the base body 11), then the tray ring 21 is rotated to embed the supporting lug 213 of the tray ring 21 into the supporting groove 16 for limiting, then the base body 11 can be driven to rotate by the rotating shaft 13, driving the wafer 40 to rotate; during rotation, the supporting lug 213 is always embedded in the supporting groove 16, thereby enhancing the stability of the wafer 40 rotation.

[0045] In some embodiments, the supporting assembly 2 further comprises a pressing plate 22; the pressing plate 22 is used to press the wafer 40 on the tray ring 21, and the wafer 40 can also be prevented from being thrown out in the case of rotation by the pressing of the pressing plate 22, thereby enhancing the stability; so as to improve the stability of the wafer 40 reaction.

[0046] As Figure 2 and Figure 3 shown, in some embodiments, the number of supporting lugs 213 is three, which are uniformly distributed along the circumference of the tray ring 21, so as to form a triangular stable support structure; based on the above structure, the supporting block 15 is also provided with three, forming three through ports 18; each supporting block 15 is provided with one supporting groove 16, thereby supporting three supporting lugs 213.

[0047] As Figure 3 and Figure 4As shown, in some embodiments, the tray ring 21 comprises a first ring supporting portion 211 and a second ring supporting portion 212, the second ring supporting portion 212 is supported on the first ring supporting portion 211, the wafer 40 is supported on the second ring supporting portion 212 and is pressed by the pressing plate 22, the first ring supporting portion 211 is made of silicon carbide, the second ring supporting portion 212 is made of graphite, and the supporting lug 213 is arranged on the first ring supporting portion 211. Since the device is applied to hoisting, when the wafer 40 is arranged on the second ring supporting portion 212, the reaction gas can pass from below to the wafer 40 through the inner ring of the first ring supporting portion 211 and the second ring supporting portion 212. Since the wafer 40 is also made of silicon carbide, the second ring supporting portion 212 made of graphite is used for supporting, so as to avoid the second ring supporting portion 212 and the wafer 40 from reacting together for a long time. The first ring supporting portion 211 is made of silicon carbide, so as to isolate the first ring supporting portion 211 made of graphite from the reaction gas as much as possible, and avoid the first ring supporting portion 211 from being corroded.

[0048] In some embodiments, in order to facilitate supporting, the tray ring 21 is provided with a plurality of abutting positions 214, so as to facilitate the mechanical hand provided with the ejector pin outside to abut the tray ring 21 through the ejector pin abutting the abutting position 214, thereby facilitating abutting. In the present embodiment, the abutting position 214 is arranged on the first ring supporting portion 211. Exemplarily, the abutting position 214 is an abutting hole, which can be but is not limited to a stepped hole. In other embodiments, the abutting position 214 can also be an abutting groove.

[0049] As Figure 1As shown, in some embodiments, the rotating shaft 13 comprises a shaft rod part and a shaft sleeve part, wherein the shaft sleeve part comprises a plurality of first arc-shaped plates 132 circumferentially spaced on the base body 11, the outer side of the first arc-shaped plates 132 is provided with a first thread, the shaft rod part comprises a rod body 131, the outer side of the rod body 131 is provided with a plurality of circumferentially spaced second arc-shaped plates 133, the outer side of the second arc-shaped plates 133 is provided with a second thread, wherein the second arc-shaped plates 133 are integrally formed with the rod body 131, when the rod body 131 is inserted into the enclosed space of the first arc-shaped plates 132, the second arc-shaped plates 133 are embedded between adjacent first arc-shaped plates 132, so that the first thread and the second thread are spliced to form a complete external thread, and the locking sleeve 4 is provided with an internal thread, so that the locking sleeve 4 can be locked on the external thread of the first arc-shaped plates 132 and the second arc-shaped plates 133, thereby adopting the segmented distribution structure of the first arc-shaped plates 132 and the second arc-shaped plates 133, so that the entire external thread is spliced by multiple threads, and since the threads of the multiple threads are not completely spliced, a small misalignment is formed, which can generate stress when the locking sleeve 4 is locked, thereby increasing the friction of the locking and playing a role of preventing loosening, further enhancing the stability of the wafer 40 during rotation. The application also provides an epitaxial device, which comprises a furnace body, the wafer carrying mechanism and a heater, the furnace body has an inner cavity, the wafer carrying mechanism is arranged in the inner cavity, and the stability of the wafer 40 during reaction is improved; the heater 3 is arranged on the side of the base body 11 away from the supporting block 15, so that the heater 3 conducts heat to the wafer 40 through the base body 11 (mainly by heat radiation). Specifically, the heater 3 is fixed to the cavity wall of the inner cavity, the heater 3 is provided with a through hole 31, the rotating shaft 13 passes through the through hole 31, so that the heater 3 is sleeved on the rotating shaft 13. More specifically, the side of the base body 11 away from the supporting block 15 is provided with a limiting table 17, the first arc-shaped plates 132 are circumferentially spaced on the limiting table 17, and the heater 3 is located between the locking sleeve 4 and the limiting table 17, so as to avoid that the heater 3 is all in contact with the base body 11 due to rotation shock and other factors, and reduce friction. In the present embodiment, the first arc-shaped plates 132 and the limiting table 17 are integrally formed.

[0050] As Figures 5 to 7As shown, in some embodiments, the epitaxial device further comprises a sleeve 20 and a low thermal conductor 30, both of which are fixed to the cavity wall of the inner cavity of the furnace body, and the specific fixing manner is not limited. For example, a support rod can be used for support and fixation. It should be noted that the heater 3 can also be fixed by a support rod penetrating through the sleeve 20 and the low thermal conductor 30. The sleeve 20 surrounds the outer periphery of the base body 11, the low thermal conductor 30 is arranged in the sleeve 20, and the low thermal conductor 30 is provided with a perforation 301 for the rotating shaft 13 to pass through, so that the rotating shaft 13 passes through, and the low thermal conductor 30 is located above the heater 3. The heater 3 is surrounded by the low thermal conductor 30 and the sleeve 20, and then the low thermal conductor 30 is heat-insulated, while reducing heat leakage and reducing the probability of danger. The low thermal conductor 30 in the present application adopts a material with a thermal conductivity less than or equal to 10 W / (m·K). For example, the low thermal conductor 30 adopts graphite felt.

[0051] In addition, as shown in Figure 5 and Figure 6 , a flow-through channel 5 is formed between the sleeve 20 and the base body 11, and the low thermal conductor 30 and / or the sleeve 20 is provided with an air inlet channel (not shown in the figure) communicating with the flow-through channel 5, so that the reaction gas rising from below can be reduced by introducing a purge gas into the flow-through channel 5 to purge the outer periphery of the base body 11, thereby reducing the probability of the reaction gas corroding the rotating shaft 13 and the heater 3 and other components, affecting their normal work.

[0052] Specifically, the sleeve 20 is provided with a first ring plate 201 in the circumferential direction, and the base body 11 is provided with a second ring plate 14 around the outer periphery. When the base body 11 is placed in the inner ring of the first ring plate 201, the first ring plate 201 and the second ring plate 14 are arranged in an upper and lower spaced manner, so as to form the above-mentioned flow-through channel 5, and the gas blows through the outer periphery of the base body 11 along the flow-through channel 5. Further, in order to reduce the backflow of the purge gas, in the present embodiment, the first ring plate 201 and the second ring plate 14 are both provided with protrusions 202, which extend along the circumferential direction of the first ring plate 201 or the second ring plate 14. The protrusions 202 of the first ring plate 201 extend towards the second ring plate 14, and the protrusions 202 of the second ring plate 14 extend towards the first ring plate 201. The protrusions 202 of the first ring plate 201 and the protrusions 202 of the second ring plate 14 are arranged in a staggered manner, so that the gas flows in a zigzag manner in the flow-through channel 5, reducing the reverse flow, thereby reducing the occurrence of backflow problems.

[0053] In the present embodiment, the protrusions 202 on the first ring plate 201, the first ring plate 201 and the sleeve 20 are integrally formed; and the protrusions 202 on the second ring plate 14, the second ring plate 14 and the bearing ring 12 are integrally formed.

[0054] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present application. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application claims.

Claims

1. A wafer carrier mechanism, characterized in that, include: A base assembly (1) includes a base body (11), on which a bearing ring (12) and a rotating shaft (13) are provided. The rotating shaft (13) and the bearing ring (12) are located on opposite sides of the base body (11). Support blocks (15) are circumferentially spaced on the inner ring of the bearing ring (12), and an opening (18) is formed between adjacent support blocks (15). A support groove (16) is provided on the side of the support block (15) facing the base body (11). The support assembly (2) includes a tray ring (21) configured to support the wafer (40); the tray ring (21) has lugs (213) distributed circumferentially thereon, which are corresponding to the opening (18), and the lugs (213) can pass through the opening (18) and can be embedded in the support groove (16).

2. The wafer carrier mechanism according to claim 1, characterized in that, The support assembly (2) further includes a pressure plate (22) for pressing the wafer (40) onto the tray ring (21).

3. The wafer carrier mechanism according to claim 1, characterized in that, The tray ring (21) includes a first ring support portion (211) and a second ring support portion (212). The second ring support portion (212) is supported on the first ring support portion (211), the wafer (40) is supported on the second ring support portion (212), and the lug (213) is disposed on the first ring support portion (211). The first ring support portion (211) is made of silicon carbide, and the second ring support portion (212) is made of graphite.

4. The wafer carrier mechanism according to claim 1, characterized in that, The tray ring (21) is provided with multiple abutment positions (214).

5. The wafer carrier mechanism according to claim 1, characterized in that, The rotating shaft (13) includes a shaft part and a bushing part. The bushing part includes a plurality of first arc-shaped plates (132) circumferentially spaced on the base body (11). The outer side of the first arc-shaped plates (132) is provided with a first thread. The shaft part includes a rod body (131). The outer periphery of the rod body (131) is provided with a plurality of second arc-shaped plates (133) circumferentially spaced. The outer side of the second arc-shaped plates (133) is provided with a second thread. When the rod body (131) is inserted into the space enclosed by the first arc-shaped plates (132), the second arc-shaped plates (133) are inserted between adjacent first arc-shaped plates (132). The second thread and the first thread are combined to form an external thread. The wafer carrying mechanism also includes a locking sleeve (4). The locking sleeve (4) is provided with an internal thread. The locking sleeve (4) is locked onto the first arc-shaped plates (132) and the second arc-shaped plates (133).

6. An extensional device, comprising a furnace body having an inner cavity, characterized in that, It also includes a wafer carrier mechanism and a heater (3) as described in any one of claims 1-5, wherein the wafer carrier mechanism is disposed within the inner cavity, and the heater (3) is disposed on the side of the base body (11) away from the support block (15), and the heater (3) is used to heat the wafer (40).

7. The epitaxial device according to claim 6, characterized in that, The heater (3) is fixed to the cavity wall of the inner cavity, the heater (3) is provided with a through hole (31), and the rotating shaft (13) passes through the heater (3).

8. The epitaxial device according to claim 7, characterized in that, The extension device further includes a sleeve (20) and a low thermal conductivity element (30). The sleeve (20) and the low thermal conductivity element (30) are both fixed to the cavity wall of the inner cavity. The sleeve (20) surrounds the outer periphery of the base body (11). The low thermal conductivity element (30) is located inside the sleeve (20). The low thermal conductivity element (30) is provided with a through hole (301) for the rotating shaft (13) to pass through.

9. The epitaxial apparatus according to claim 8, characterized in that, A flow channel (5) is formed between the sleeve (20) and the base body (11) to allow purge gas to flow around the base body (11). An air inlet channel communicating with the flow channel (5) is provided on the low thermal conductivity body (30) and / or the sleeve (20).

10. The epitaxial apparatus according to claim 9, characterized in that, The sleeve (20) is provided with a first ring plate (201) in the circumferential direction, and the base body (11) is provided with a second ring plate (14) around its outer periphery. When the base body (11) is placed in the inner ring of the first ring plate (201), the first ring plate (201) and the second ring plate (14) are arranged vertically at intervals to form the flow channel (5).

11. The epitaxial apparatus according to claim 10, characterized in that, The first ring plate (201) and the second ring plate (14) are provided with protrusions (202). The protrusions (202) of the first ring plate (201) extend toward the second ring plate (14), and the protrusions (202) of the second ring plate (14) extend toward the first ring plate (201). The protrusions (202) of the first ring plate (201) and the protrusions (202) of the second ring plate (14) are misaligned.

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