Ring member, wafer bearing pedestal, bearing assembly and process chamber

Abstract

The utility model provides an annular piece, a wafer bearing base, a bearing assembly and a process chamber, relates to the technical field of semiconductor processing, and aims to solve the problem that the back surface of an existing wafer is easily etched by hydrogen. The annular piece is used for being matched with a wafer bearing base, and the total number of axial extending circumferential faces and radial extending end faces, used for being correspondingly attached to the wafer bearing base, of the bottom of the annular piece is larger than or equal to four. The etching of hydrogen on the back surface of the wafer can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor processing, in particular to an annular part, a bearing component and a process chamber. Background Art

[0002] Silicon carbide (SiC) is a third-generation semiconductor material with a wide bandgap, high breakdown electric field, high thermal conductivity, high melting point, and high saturated electron drift velocity. Power devices made of SiC can improve the efficiency of power conversion and achieve miniaturization of power devices.

[0003] SiC epitaxial technology is a technology that uses chemical vapor deposition (CVD) to prepare single crystal thin films. Its reaction sources are TCS (SiHCl3) and C2H4, and the N-type doping source is N2. The epitaxial growth and doping principles are step flow growth mode and competitive mechanism, respectively. The crystal type (4H-SiC), thickness and doping concentration of the epitaxial layer can be accurately controlled.

[0004] At present, the performance of domestic medium and low voltage power devices is basically comparable to that of imported products, while the performance of high voltage and ultra-high voltage power devices is still far behind that of foreign products. The withstand voltage of SiC power devices is proportional to the thickness of the SiC epitaxial layer. The thickness of the SiC epitaxial layer required for high voltage and ultra-high voltage power devices is >60μm. Using a high-speed epitaxial process (epitaxial rate: ≈60μm / h), the epitaxial layer growth time will exceed 1h. While the epitaxial growth is taking place on the surface of the SiC wafer in the graphite cavity, the graphite ring that supports and fixes the SiC wafer There will also be SiC particles attached, and the growth rate is fastest at the outer and inner edges of the graphite ring. The large accumulation of SiC particles at the inner edge will hinder the wafer placement operation, reduce the service life of the graphite ring, and reduce the number of times the graphite ring is used for continuous debugging of thick film processes; the large accumulation of SiC particles at the outer edge will gradually reduce the adhesion strength of SiC particles. After long-term growth, the SiC particles will be loosened after being etched by the carrier gas H2, and the number of SiC particles blown to the surface of the wafer will increase, resulting in an increase in fatal defects in the SiC epitaxial layer, which seriously affects the performance of power devices. In addition, when H2 is used as a rotating gas, H2 will enter the back of the wafer along the contact surface of the graphite tray and the graphite ring, react with the SiC wafer, and etch the back of the wafer. For a long time, the roughness of the back of the SiC wafer will deteriorate, and even scratches will appear. Because the graphite part contains impurities of other components, these impurities will diffuse outward at high temperatures. When the wafer and the graphite part are in direct contact, the impurities will be adsorbed on the back of the wafer, resulting in a mist distribution. Utility Model Content

[0005] The first purpose of the utility model is to provide a ring-shaped component to alleviate the technical problem that the back side of the existing wafer is easily etched by hydrogen.

[0006] The annular member provided in the first aspect of the utility model is used to cooperate with a wafer supporting base, and the total number of the axially extending circumferential surface and the radially extending end surface of the bottom of the annular member corresponding to and fitting with the wafer supporting base is greater than or equal to four.

[0007] The beneficial effects of the annular member provided in the first aspect of the utility model are:

[0008] By setting the total number of axially extending circumferential surfaces and radially extending end surfaces of the bottom of the ring member for correspondingly fitting with the wafer supporting base to be greater than or equal to four, the number and area of ​​the fitting surfaces can be increased. During the process, H2, as the gas that rotates the wafer supporting base, may enter the back of the wafer. Therefore, by increasing the number of contact surfaces between the ring member and the wafer supporting base, H2 flowing from the bottom to the top is prevented from entering the back of the wafer, reducing the total amount of H2 on the back of the wafer. Therefore, the degree of hydrogen etching on the back of the wafer can be reduced.

[0009] In an optional technical solution, the annular member is provided with a radial inner flange, and the lower surface of the annular member is provided with a first radial extension portion and an annular lower flange, and the annular lower flange is located on the outside of the first radial extension portion; the lower surface of the radial inner flange, the part of the inner circumference of the annular member located below the radial inner flange, the first radial extension portion and the inner circumference of the annular lower flange are configured to fit with the wafer supporting base.

[0010] In an optional technical solution, the annular member is also provided with a second radial extension portion, the second radial extension portion is located between the first radial extension portion and the annular lower flange, and a transition portion is provided between the second radial extension portion and the first radial extension portion; the transition portion and the second radial extension portion are configured to both fit with the wafer supporting base.

[0011] In an optional technical solution, a height difference between the first radially extending portion and the second radially extending portion is 0.2 mm to 1.5 mm.

[0012] In an optional technical solution, a third radial extension portion is provided on the upper surface of the annular member, and the third radial extension portion is connected to the inner edge and outer edge of the annular member through an arc chamfer, and the arc chamfer has a smooth transition with the third radial extension portion, the inner edge and the outer edge.

[0013] In an optional technical solution, the radius of the arc chamfer is 0.1 mm to 3 mm.

[0014] In an optional technical solution, when the annular member carries a wafer, the third radially extending portion is configured to have a height consistent with an upper surface of the wafer.

[0015] In an optional technical solution, a plurality of positioning pins are provided on the lower surface of the annular member, and the positioning pins are configured to match the positioning holes provided on the wafer supporting base.

[0016] In an optional technical solution, the upper surface of the annular member is provided with a silicon carbide coating.

[0017] The second purpose of the utility model is to provide a wafer supporting base to alleviate the technical problem that the back side of the existing wafer is easily etched by hydrogen.

[0018] The wafer supporting base provided in the second aspect of the utility model is used to cooperate with the annular member thereon, and the total number of the axially extending circumferential surface and the radially extending end surface of the wafer supporting base corresponding to the annular member is greater than or equal to four.

[0019] The beneficial effects of the wafer supporting base provided by the second aspect of the utility model are:

[0020] By providing the wafer support base with a total number of axially extending peripheral surfaces and radially extending end surfaces for correspondingly fitting with the annular member being greater than or equal to four, the number and area of ​​the fitting surfaces can be increased. During the process, H2, as the gas that rotates the wafer support base, may enter the back of the wafer. Therefore, by increasing the number of contact surfaces between the annular member and the wafer support base, H2 flowing from the bottom to the top is prevented from entering the back of the wafer, thereby reducing the total amount of H2 on the back of the wafer. Therefore, the degree of hydrogen etching on the back of the wafer can be reduced.

[0021] In an optional technical solution, the upper surface of the wafer supporting base is provided with an annular upper flange, the annular member is provided with a radial inner flange, the top surface of the annular upper flange can be fitted with the lower surface of the radial inner flange, and the outer peripheral surface of the annular upper flange can be fitted with the inner peripheral surface of the annular member below the radial inner flange.

[0022] The lower surface of the annular member is provided with a first radial extension portion and an annular lower flange, and the annular lower flange is located outside the first radial extension portion; the wafer supporting base can be fitted with the first radial extension portion and the annular lower flange.

[0023] In an optional technical solution, the annular member is also provided with a second radial extension portion, the second radial extension portion is located between the first radial extension portion and the annular lower flange, and a transition portion is provided between the second radial extension portion and the first radial extension portion; the wafer supporting base is configured to fit with the transition portion and the second radial extension portion.

[0024] In an optional technical solution, the upper surface of the wafer supporting base further has a groove, the groove is located radially inward of the annular upper flange, and the groove is configured to be spaced apart from the wafer.

[0025] In an optional technical solution, the bottom of the groove is configured to be 0.5 mm to 2.5 mm away from the bottom surface of the wafer; and / or,

[0026] The distance between the bottom of the groove and the upper surface of the radial inner flange is 0.5 mm to 2.5 mm.

[0027] In an optional technical solution, the wafer supporting base is provided with a plurality of positioning holes, and the positioning holes are configured to match with positioning pins provided on the annular member.

[0028] The third object of the present invention is to provide a carrier assembly to alleviate the technical problem that the back side of the conventional wafer is easily etched by hydrogen.

[0029] The supporting assembly provided in the third aspect of the utility model comprises any one of the above-mentioned annular parts and any one of the above-mentioned wafer supporting bases, and the total number of pairs of axially extending circumferential surfaces and radially extending end surfaces of the wafer supporting base fitting with the annular part is greater than or equal to four pairs.

[0030] The beneficial effects of the bearing assembly provided by the third aspect of the utility model are:

[0031] By providing the bottom of the annular member of the bearing assembly and the wafer bearing base with a total number of pairs of axially extending peripheral surfaces and radially extending end surfaces corresponding to the wafer bearing base being greater than or equal to four pairs, the number and area of ​​the bonding surfaces can be increased. During the process, H2, as the gas that rotates the wafer bearing base, may enter the back of the wafer. Therefore, by increasing the number of contact surfaces between the annular member and the wafer bearing base, H2 flowing from the bottom to the top is prevented from entering the back of the wafer, reducing the total amount of H2 on the back of the wafer. Therefore, the degree of hydrogen etching on the back of the wafer can be reduced.

[0032] The fourth object of the utility model is to provide a process chamber to alleviate the technical problem that the back side of the existing wafer is easily etched by hydrogen.

[0033] A fourth aspect of the present invention provides a process chamber, which comprises a cavity and the above-mentioned supporting assembly, wherein the supporting assembly is arranged in the cavity.

[0034] By arranging the above-mentioned supporting assembly in the process chamber, the process chamber accordingly has all the advantages of the above-mentioned supporting assembly, which will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments or background technologies of the present invention, the drawings required for use in the embodiments or background technology descriptions are briefly introduced below. Obviously, the drawings described below are merely embodiments of the present invention, and ordinary technicians in this field can obtain other drawings based on the provided drawings without paying any creative work.

[0036] Figure 1 It is a structural schematic diagram of a wafer supporting structure in the related art;

[0037] Figure 2 It is a structural schematic diagram of a graphite ring in a wafer supporting structure in the related art;

[0038] Figure 3 A schematic diagram of the structure of a graphite tray of a wafer carrying structure in the related art;

[0039] Figure 4 A schematic diagram of the structure of a bearing assembly provided in an embodiment of the utility model;

[0040] Figure 5 A structural schematic diagram of an implementation method of a load-bearing assembly provided in an embodiment of the utility model;

[0041] Figure 6 A top view of the annular member provided in the first embodiment of the utility model;

[0042] Figure 7 A top view of the wafer supporting base provided in the second embodiment of the utility model.

[0043] Description of reference numerals:

[0044] 10-ring member; 11-third radial extension; 12-inner edge; 13-outer edge; 14-arc chamfer; 15-radial inner flange; 16-first radial extension; 17-second radial extension; 18-positioning pin; 19-annular lower flange;

[0045] 20-wafer supporting base; 21-annular upper flange; 22-groove; 23-positioning hole;

[0046] 30-wafer;

[0047] 100-axially extending circumferential surface; 200-radially extending end surface. DETAILED DESCRIPTION

[0048] In the related technology, Figure 1 It is a structural schematic diagram of a wafer supporting structure in the related technology of the utility model; Figure 2 It is a structural schematic diagram of a graphite ring in a wafer supporting structure in the related technology of the utility model; Figure 3 The structure diagram of the graphite tray of the wafer supporting structure in the related technology of the utility model is as follows; Figure 1-Figure 3 As shown, the wafer bearing structure is composed of a graphite tray 1 and a graphite ring 2; the upper surface of the graphite ring 2 is composed of a wafer-like groove 4 and a first plane 5, and the upper surface of the graphite tray 1 is composed of a raised wafer-like structure 6 and a second plane 7. The wafer 3 is placed in the groove 4 of the graphite ring 2, the straight positioning edges of the wafer 3 and the groove 4 are fixed to each other, and the wafer 3 rotates with the graphite ring 2, the graphite ring 2 is placed above the graphite tray 1, the graphite tray 1 and the graphite ring 2 are fitted, the straight positioning edges are fixed to each other, and the graphite ring 2 rotates with the graphite tray 1;

[0049] However, in the above solution, during a long process, H2 in the chamber will enter between the graphite trays 1, and the back side of the wafer 3 will be severely etched by H2, resulting in scratches on the back side of the wafer 3.

[0050] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific embodiments of the utility model are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0051] Embodiment 1:

[0052] Figure 4 A schematic diagram of the structure of the load-bearing assembly provided in an embodiment of the utility model; Figure 4 As shown, the annular member 10 provided in the first embodiment of the utility model is used to cooperate with the wafer supporting base 20, and the total number of the axially extending circumferential surface 100 and the radially extending end surface 200 at the bottom of the annular member 10 correspondingly fitting with the wafer supporting base 20 is greater than or equal to four.

[0053] In normal use, the wafer supporting base 20 supports the annular member 10, and the annular member 10 is used to support the wafer 30. Therefore, the bottom of the annular member 10 contacts the wafer supporting base 20, and the axially extending peripheral surface 100 and the radially extending end surface 200 of the annular member 10 contact the corresponding surfaces of the wafer supporting base 20.

[0054] In the present application, the radially extending end surface 200 is not limited to a surface that is completely perpendicular to the axis. For example, the surface may also be at a smaller angle with the axis, such as 2°, 5°, or even 10°, or even 15°. The radially extending end surface 200 may not be a plane, and may even be a curved surface that is uneven along the radial direction. Similarly, the axially extending peripheral surface 100 is not limited to a surface that is completely parallel to the axis. The axially extending peripheral surface 100 may also have a smaller angle with the axis, such as 2°, 5°, or even 10°, or even 15°.

[0055] By setting the total number of the axially extending peripheral surface 100 and the radially extending end surface 200 of the bottom of the ring 10 for correspondingly fitting with the wafer supporting base 20 to be greater than or equal to four, the number and area of ​​the fitting surfaces can be increased. When the process is in progress, for example, H2, which is used as a gas to rotate the wafer supporting base 20, may enter the back of the wafer 30, so by increasing the number of contact surfaces between the ring 10 and the wafer supporting base 20, H2 flowing from the bottom to the top is prevented from entering the back of the wafer 30, and the total amount of H2 on the back of the wafer 30 is reduced. Therefore, the degree of H2 etching on the back of the wafer 30 can be reduced.

[0056] Figure 5 A structural diagram of an implementation method of a load-bearing assembly provided in an embodiment of the utility model; Figure 4 and Figure 5 As shown, optionally, the ring member 10 is provided with a radial inner flange 15, and the lower surface of the ring member 10 is provided with a first radial extension portion 16 and an annular lower flange 19, and the annular lower flange 19 is located on the outside of the first radial extension portion 16; the lower surface of the radial inner flange 15, the part of the inner circumference of the ring member 10 located below the radial inner flange 15, the first radial extension portion 16 and the inner circumference of the annular lower flange 19 are configured to fit with the wafer supporting base 20.

[0057] In this embodiment, the height of the radial inner flange 15 is 0.5 mm to 2 mm, and the width is 0.5 mm to 2 mm; the height difference between the upper surface of the radial inner flange 15 and the third radial extension portion 11 of the ring 10 is 0.35 mm to 2 mm. The radial inner flange 15 extends along the circumference of the ring 10 and protrudes inwardly, and the radial inner flange 15 is used to support the wafer 30.

[0058] Setting the height of the radial inner flange 15 within the above range can achieve effective support for the wafer 30. Moreover, setting the width of the radial inner flange 15, that is, the degree to which the radial inner flange 15 protrudes radially inward, to the above size can ensure that the edge of the wafer 30 can be fully supported by the radial inner flange 15 while leaving an appropriate gap between the edge of the wafer 30 and the inner edge 12 to prevent the inner edge 12 from immediately causing the wafer 30 to be stuck in the ring 10 due to the attachment of silicon carbide particles.

[0059] like Figure 5As shown, in this implementation, starting from the lower end of the inner circumference of the radial inner flange 15 of the ring 10, the lower surface of the radial inner flange 15, the portion of the inner circumference of the ring 10 located below the radial inner flange 15, the first radial extension 16 and the inner circumference of the annular lower flange 19 are sequentially arranged in the radial direction to fit with the corresponding surface of the wafer supporting base 20. Among them, the lower surface of the radial inner flange 15 and the first radial extension 16 belong to the radially extending end surface 200, while the portion of the inner circumference of the ring 10 located below the radial inner flange 15 and the inner circumference of the annular lower flange 19 belong to the axially extending circumferential surface 100. Therefore, in this implementation, the number of the axially extending circumferential surfaces 100 of the ring 10 for correspondingly fitting with the wafer supporting base 20 is two, and the number of the radially extending end surfaces 200 is two, that is, the total number of the axially extending circumferential surfaces 100 and the radially extending end surfaces 200 of the ring 10 for correspondingly fitting with the wafer supporting base 20 is four.

[0060] By setting the lower surface of the radial inner flange 15, the inner circumference of the ring 10 located below the radial inner flange 15, the first radial extension portion 16 and the inner circumference of the lower annular flange 19 to fit with the wafer support base 20, four radially extending end faces 200 and axially extending circumferential faces 100 corresponding to the wafer support base 20 can be formed on the ring 10, and the number of fitted faces is increased compared to the related art. Moreover, among the faces of the ring 10 and the wafer support base 20, each two adjacent faces are roughly vertical, and even if H2 flows toward the back of the wafer 30, multiple near-vertical turns can also significantly consume its energy and reduce its speed, further reducing the H2 concentration on the back of the wafer 30 and weakening the etching of the back of the wafer 30.

[0061] like Figure 4 As shown, optionally, the annular member 10 is further provided with a second radial extension portion 17, the second radial extension portion 17 is located between the first radial extension portion 16 and the annular lower flange 19, and a transition portion is provided between the second radial extension portion 17 and the first radial extension portion 16; the transition portion and the second radial extension portion 17 are configured to both fit with the wafer supporting base 20.

[0062] The second radially extending portion 17 is lower than the first radially extending portion 16. Figure 4As shown, in this implementation, starting from the lower end of the inner circumference of the radial inner flange 15 of the ring 10, the lower surface of the radial inner flange 15, the portion of the inner circumference of the ring 10 located below the radial inner flange 15, the second radial extension 17, the transition portion, the first radial extension 16 and the inner circumference of the annular lower flange 19 are sequentially arranged in the radial direction to fit the corresponding surface of the wafer supporting base 20. Among them, the lower surface of the radial inner flange 15, the second radial extension 17 and the first radial extension 16 belong to the radial extension end surface 200, and the portion of the inner circumference of the ring 10 located below the radial inner flange 15, the transition portion and the inner circumference of the annular lower flange 19 belong to the axial extension circumferential surface 100. Therefore, in this implementation, the number of axially extending circumferential surfaces 100 of the ring member 10 for correspondingly fitting with the wafer supporting base 20 is three, and the number of radially extending end surfaces 200 is three, that is, the total number of axially extending circumferential surfaces 100 and radially extending end surfaces 200 of the ring member 10 for correspondingly fitting with the wafer supporting base 20 is six.

[0063] By additionally providing the second radial extension portion 17 and the transition portion configured to fit with the wafer support base 20, six radially extending end faces 200 and axially extending peripheral faces 100 corresponding to the wafer support base 20 can be formed on the ring member 10, and the number of fitted faces is increased compared to the related art. Moreover, among the faces of the ring member 10 and the wafer support base 20, each two adjacent faces are substantially vertical, and even if H2 flows toward the back of the wafer 30, multiple near-vertical turns can significantly consume its energy and reduce its speed, further reducing the H2 concentration on the back of the wafer 30 and weakening the etching on the back of the wafer 30.

[0064] Optionally, a height difference between the first radially extending portion 16 and the second radially extending portion 17 is 0.2 mm to 1.5 mm.

[0065] By setting the height difference between the first radial extension portion 16 and the second radial extension portion 17 to the above range, that is, the height of the transition portion is within the above range, an effective longitudinal channel length can be formed between the first radial extension portion 16 and the second radial extension portion 17, and the direction of the H2 gas flow is changed twice. This effectively weakens the energy of the gas flow when it enters below the wafer 30, reduces the H2 concentration below the wafer 30, and reduces the etching on the back of the wafer 30.

[0066] After careful research, the applicant found that when the solution of the related technology grows a SiC epitaxial layer with a thickness higher than 60μm, a large amount of SiC particles will grow on the surface of the graphite ring 2 because the process time of the epitaxial stage is about 1h. In particular, at the inner and outer right-angle edges of the upper surface of the graphite ring 2, after growing for about two to three furnaces, there are too many SiC particles attached to the edge of the upper surface of the graphite ring 2. As the SiC particles accumulate, the adhesion strength of SiC gradually decreases. During the process, some loose SiC particles will be blown to the surface of the wafer, causing fatal defects in the SiC epitaxial layer. In addition, the thicker SiC particles accumulated at the inner edge of the graphite ring 2 will also cause the wafer to be stuck in the groove 4 of the graphite ring, making it difficult to take the wafer.

[0067] In order to alleviate the above-mentioned problems of easy accumulation of SiC particles at the inner and outer edges of the graphite ring and the resulting problems, as Figure 4 As shown, optionally, a third radial extension portion 11 is provided on the upper surface of the ring 10, and the third radial extension portion 11 is connected to the inner edge 12 and the outer edge 13 of the ring 10 through an arc chamfer 14, and the arc chamfer 14 has a smooth transition with the third radial extension portion 11, the inner edge 12 and the outer edge 13.

[0068] Specifically, in this embodiment, the ring 10 is located at the edge of the wafer 30 , a portion of the ring 10 is located directly below the radial inner side of the edge of the wafer 30 , and a portion of the ring 10 is located radially outside the edge of the wafer 30 .

[0069] In this embodiment, the third radial extension portion 11 is not limited to a plane, but can also be a curved surface, as long as the third radial extension portion 11 is generally horizontal. However, the chamfer at the connection must be tangent to the connection between the third radial extension portion 11 and the outer edge 13 and the inner edge 12.

[0070] The smooth transition at the connection does not only mean that the direction of the arc chamfer 14 changes gradually, and no convex edges caused by sudden changes in direction appear on the arc chamfer 14, but also that the arc chamfer 14 is tangent to the connection positions with the third radial extension 11, the outer edge 13, and the inner edge 12. Moreover, in this embodiment, the arc chamfer 14 can be an arc, such as a quarter circle, and in another implementation, it can also be a quarter of an ellipse, which can also achieve a similar effect.

[0071] The smooth transition between the inner and outer sides of the ring 10 surface can inhibit the nucleation rate of SiC, reduce the growth rate of SiC particles, and reduce the amount of attachment. The adhesion strength of SiC particles gradually decreases with the increase of the amount of attachment. Therefore, reducing the SiC particles on the surface of the ring 10 can reduce the number of SiC particles blown onto the surface of the wafer 30, reduce the number of fatal defects in the SiC epitaxial layer, and increase the yield of the wafer 30 to prepare the chip. In addition, reducing the total amount of SiC particles accumulated on the arc chamfer 14 on the inner side of the ring 10 can also extend the use time of the wafer 30 without being stuck in the ring 10.

[0072] Optionally, the radius of the arc chamfer 14 is 0.1 mm to 3 mm.

[0073] Setting the radius of the arc chamfer 14 to the above value can reduce the severity of the sudden change in the air flow velocity when the third radial extension portion 11 intersects the inner edge 12 and the outer edge 13, thereby slowing down the nucleation rate of SiC, reducing the growth rate of silicon carbide particles, and reducing the adhesion amount.

[0074] like Figure 4 As shown, optionally, when the ring 10 carries the wafer 30 , the third radially extending portion 11 is configured to have a height consistent with the upper surface of the wafer 30 .

[0075] Among them, the third radial extension portion 11 is configured to have a height consistent with the upper surface of the wafer 30, which means that when the wafer 30 is placed on the ring member 10, the upper surface of the third radial extension portion 11 can be slightly higher than the upper surface of the wafer 30, or slightly lower than the upper surface of the wafer 30 or slightly lower than the lower surface of the wafer 30.

[0076] By configuring the third radial extension portion 11 to be consistent with the upper surface of the wafer 30, the sudden change in direction of the airflow at the edge of the upper surface of the wafer 30, when the airflow descends from other components of the wafer 30 to a position close to the edge of the upper surface of the wafer 30, or the sudden change in direction of the airflow climbing from the upper surface of the wafer 30 to the remaining parts, can be reduced, thereby reducing the impact of airflow disturbances on the edge area close to the upper surface of the wafer 30, thereby improving the processing quality.

[0077] Figure 6 A top view of a ring member provided in Embodiment 1 of the present utility model; Figure 4-Figure 6 As shown, optionally, a plurality of positioning pins 18 are provided on the lower surface of the ring 10 , and the positioning pins 18 are configured to match with positioning holes 23 provided on the wafer supporting base 20 .

[0078] Specifically, in this embodiment, the positioning pin 18 is arranged on the first radial extension portion 16, that is, arranged on the lower end surface of the ring member 10; more specifically, in this embodiment, three positioning pins 18 are arranged evenly distributed along the circumference, and the positioning holes 23 are arranged on the upper end surface of the wafer supporting base 20 and matched with the positioning pins 18. The positioning pins 18 can be integrally formed with the ring member 10.

[0079] By providing the positioning pins 18 , they can match the positioning holes 23 on the wafer supporting base 20 , and can effectively realize the torque transmission between the wafer supporting base 20 and the ring member 10 , thereby facilitating the control of the rotation of the wafer 30 .

[0080] The applicant has found through intensive research that in the related art, the components of the wafer bearing structure are mainly made of graphite. The impurity components inside the graphite material diffuse outward at high temperature, and are adsorbed after diffusing to the back of the wafer, resulting in atomization. In order to solve the atomization problem caused by the impurities of the wafer bearing structure diffusing to the back of the wafer and being adsorbed, the upper surface of the ring 10 is optionally provided with a silicon carbide coating.

[0081] In this embodiment, the upper surface of the ring member 10 includes the upper surface of the radial inner flange 15 of the ring member 10 , the arc chamfer 14 and the third radial extension portion 11 .

[0082] Generally speaking, the bearing component is made of pure graphite material. Affected by the purity of the graphite material, impurities in the graphite material diffuse outward at high temperature. When in direct contact with the wafer 30, the impurities are adsorbed on the back of the SiC material wafer 30, causing a fogging phenomenon on the back of the wafer 30. By providing a dense SiC coating on the upper surface of the ring 10, the impurities in the graphite of the ring 10 can be prevented from diffusing outward;

[0083] Since the material of the ring part 10 is usually graphite material, a silicon carbide coating is provided on the upper surface of the radial inner flange 15 of the ring part 10, the arc chamfer 14, the third radial extension portion 11, and the outer side of the annular lower flange 19. This can prevent impurities inside the material of the ring part 10 from being adsorbed by the wafer 30 when it contacts with the wafer 30, so that the contact portion between the wafer 30 and the ring part 10 will not be atomized.

[0084] Embodiment 2:

[0085] like Figure 4 As shown, the wafer supporting base 20 provided in the second embodiment of the utility model is used to cooperate with the ring member 10 thereon, and the total number of the axially extending peripheral surface 100 and the radially extending end surface 200 of the wafer supporting base 20 corresponding to the ring member 10 is greater than or equal to four.

[0086] By providing the wafer supporting base 20 with a total number of axially extending peripheral surfaces 100 and radially extending end surfaces 200 corresponding to the annular member 10 being greater than or equal to four, the number and area of ​​the bonding surfaces can be increased. During the process, H2, as a gas that rotates the wafer supporting base 20, may enter the back of the wafer 30. Therefore, by increasing the number of contact surfaces between the annular member 10 and the wafer supporting base 20, H2 flowing from the bottom to the top is prevented from entering the back of the wafer 30, thereby reducing the total amount of H2 on the back of the wafer 30. Therefore, the degree of H2 etching on the back of the wafer 30 can be reduced.

[0087] like Figure 4 and Figure 5 As shown, optionally, the upper surface of the wafer supporting base 20 is provided with an annular upper flange 21, and the ring member 10 is provided with a radial inner flange 15, the top surface of the annular upper flange 21 can be fitted with the lower surface of the radial inner flange 15, and the outer circumferential surface of the annular upper flange 21 can be fitted with the inner circumferential surface of the ring member 10 located below the radial inner flange 15;

[0088] The lower surface of the ring 10 is provided with a first radial extension portion 16 and an annular lower flange 19 , and the annular lower flange 19 is located outside the first radial extension portion 16 ; the wafer supporting base 20 can fit with the first radial extension portion 16 and the annular lower flange 19 .

[0089] like Figure 5 As shown, in this implementation, on the upper surface of the wafer supporting base 20, starting from the upper edge of the inner circumference of the annular upper flange 21, radially outward, there are sequentially provided the top surface of the annular upper flange 21 that fits with the lower surface of the radial inner flange 15, the outer circumference of the annular upper flange 21 that fits with the portion of the inner circumference of the ring member 10 located below the radial inner flange 15, the top surface of the wafer supporting base 20 that fits with the first radial extension portion 16, and the outer circumference of the wafer supporting base 20 that fits with the inner circumference of the annular lower flange 19. Among them, the top surface of the annular upper flange 21 and the surface of the wafer supporting base 20 that fits with the first radial extension portion 16 belong to the radially extending end surface 200, and the outer circumference of the annular upper flange 21 and the outer circumference of the wafer supporting base 20 are the axially extending circumferential surface 100. Therefore, in this implementation, the number of axially extending circumferential surfaces 100 of the wafer supporting base 20 that are used to correspond to the wafer supporting base 20 is two, and the number of radially extending end surfaces 200 is two, that is, the total number of axially extending circumferential surfaces 100 and radially extending end surfaces 200 of the wafer supporting base 20 that are used to correspond to the annular member 10 is four.

[0090] By providing the annular upper flange 21, four radially extending end faces 200 and axially extending peripheral faces 100 that are bonded to the corresponding surfaces of the annular member 10 can be formed on the wafer supporting base 20, and the number of bonded faces is increased compared to the related art. Moreover, among the faces of the wafer supporting base 20 that are bonded to the annular member 10, every two adjacent faces are substantially vertical, and even if H2 flows toward the back of the wafer 30, multiple near-vertical turns can significantly consume its energy and reduce its speed, further reducing the H2 concentration on the back of the wafer 30 and weakening the etching on the back of the wafer 30.

[0091] like Figure 4 As shown, optionally, the annular member 10 is further provided with a second radial extension portion 17, the second radial extension portion 17 is located between the first radial extension portion 16 and the annular lower flange 19, and a transition portion is provided between the second radial extension portion 17 and the first radial extension portion 16; the wafer supporting base 20 is configured to fit with the transition portion and the second radial extension portion 17.

[0092] In this implementation, on the upper surface of the wafer supporting base 20, starting from the upper edge of the inner circumferential surface of the annular upper flange 21, radially outward, there are sequentially provided with a top surface of the annular upper flange 21 that is in contact with the lower surface of the radial inner flange 15, an outer circumferential surface of the annular upper flange 21 that is in contact with the portion of the inner circumferential surface of the annular member 10 located below the radial inner flange 15, a radially extending end surface 200 that is in contact with the second radial extension portion 17, an axially extending circumferential surface 100 that is in contact with the transition portion, a top surface of the wafer supporting base 20 that is in contact with the first radial extension portion 16, and an outer circumferential surface of the wafer supporting base 20 that is in contact with the inner circumferential surface of the annular lower flange 19. Therefore, in this implementation, the number of axially extending circumferential surfaces 100 of the wafer supporting base 20 that are used to correspondingly fit with the wafer supporting base 20 is three, and the number of radially extending end surfaces 200 is three, that is, the total number of axially extending circumferential surfaces 100 and radially extending end surfaces 200 of the wafer supporting base 20 that are used to correspondingly fit with the annular member 10 is six.

[0093] By additionally providing a surface configured to fit with the second radial extension portion 17 and the transition portion on the wafer support base 20, six radially extending end faces 200 and axially extending peripheral faces 100 corresponding to the ring member 10 can be formed on the wafer support base 20, and the number of fitted surfaces is increased compared to the related art. Moreover, among the surfaces where the ring member 10 fits with the wafer support base 20, each two adjacent surfaces are substantially vertical, and even if H2 flows toward the back of the wafer 30, multiple near-vertical turns can significantly consume its energy and reduce its speed, further reducing the H2 concentration on the back of the wafer 30 and weakening the etching on the back of the wafer 30.

[0094] The applicant has found through intensive research that in the related art, the back of the wafer is in direct contact with the upper surface of the graphite tray 1, and the heat of the graphite tray 1 is directly diffused to the wafer. During a long process, at a high temperature, the back of the wafer will be severely etched by H2, and scratches will appear on the back. Moreover, in the related art, the impurity components inside the graphite tray 1 diffuse outward at high temperature, and are adsorbed after diffusing to the back of the wafer, resulting in atomization. In order to alleviate or even solve the problem of atomization caused by the graphite tray diffusing to the back of the wafer and being adsorbed, as Figure 4 and Figure 5 As shown, optionally, the upper surface of the wafer supporting base 20 further has a groove 22 , and the groove 22 is located radially inward of the annular upper flange 21 , and the groove 22 is configured to be spaced apart from the wafer 30 .

[0095] In this embodiment, the groove 22 is an arc-shaped groove 22, the upper part of the side wall of the groove 22 is the inner circumference of the annular upper flange 21, the bottom of the groove 22 is lower than the upper surface of the first radial extension portion 16, and the bottom of the groove 22 is a plane.

[0096] By setting the groove 22 relative to the back side of the wafer 30, on the one hand, the distance between the bottom of the groove 22 and the back side of the wafer 30 can be increased, thereby reducing the heat transfer rate from the wafer supporting base 20 to the back side of the wafer 30 and lowering the temperature of the back side of the wafer 30; on the other hand, the volume of the cavity on the back side of the wafer 30 can be effectively increased, and even if H2 enters, the H2 concentration in the space on the back side of the wafer 30 can be reduced. The SiC wafer 30 reacts with H2 at high temperature, causing the back side of the SiC wafer 30 to be etched. Reducing the H2 concentration and the temperature of the back side of the wafer 30 can reduce the etching rate of the back side of the SiC wafer 30 and reduce scratches.

[0097] By locating the upper surface of the wafer supporting base 20 in the area directly below the inner side of the radial inner flange 15, which is lower than the upper surface of the radial inner flange 15, the upper surface of the groove 22 of the wafer supporting base 20 can be prevented from directly contacting the back side of the wafer 30, thereby increasing the distance between the wafer 30 and the upper surface of the groove 22, and the impurities inside the wafer supporting base 20 can basically not diffuse to the back side of the wafer 30, so that the suspended part of the wafer 30 will not be atomized. Thus, the quality of the back side of the entire wafer 30 is improved.

[0098] Optionally, the bottom of the groove 22 is configured to be 0.5 mm to 2.5 mm away from the bottom surface of the wafer 30 ; and / or the bottom of the groove 22 is configured to be 0.5 mm to 2.5 mm away from the upper surface of the radial inner flange 15 .

[0099] Since in actual production, the bottom surface of the wafer 30 may not be guaranteed to be absolutely flat during processing, the present embodiment includes the situation in which the distance between the bottom of the groove 22 and the bottom surface of the wafer 30 is 0.5 mm to 2.5 mm in actual production. Of course, the bottom of the groove 22 of the wafer supporting base 20 may also be 0.5 mm to 2.5 mm lower than the upper surface of the radial inner flange 15.

[0100] When the distance between the bottom of the groove 22 and the bottom surface of the wafer 30 is less than 0.5 mm, the space on the back of the wafer 30 increases too little, and the H2 concentration is reduced to a limited extent, so that the degree of H2 etching on the back of the wafer 30 cannot be significantly reduced. When the distance is greater than 2.5 mm, while ensuring that the outer dimensions of the supporting component remain unchanged, the central area of ​​the wafer supporting base 20 will be too thin, reducing the overall strength of the wafer supporting base 20, making the wafer supporting base 20 easy to break during high-temperature processes.

[0101] The bottom of the groove 22 is arranged at the above-mentioned distance from the bottom surface of the wafer 30. On the one hand, it can ensure that the space under the wafer 30 is increased to effectively dilute the H2 concentration. On the other hand, it can also ensure the rigidity of the bearing component as much as possible while ensuring that the outer dimensions of the bearing component remain unchanged, thereby improving the reliability of the bearing component.

[0102] Figure 7 A top view of a wafer support base provided in the second embodiment of the present invention; Figure 7 As shown, optionally, the wafer supporting base 20 is provided with a plurality of positioning holes 23 , and the positioning holes 23 are configured to match with the positioning pins 18 provided on the ring member 10 .

[0103] In this embodiment, a positioning hole 23 is provided on the upper end surface of the wafer supporting base 20, and is provided corresponding to the positioning pin 18 provided on the lower surface of the ring member 10. Specifically, the number of the positioning holes 23 and the positioning pin 18 is three, and they are evenly arranged along the circumference. In this embodiment, the positioning hole 23 can be a countersunk hole, which can reduce the leakage of H2 from the positioning hole 23.

[0104] Embodiment three:

[0105] like Figure 4 and Figure 5 As shown, the supporting assembly provided in the third embodiment of the utility model includes the annular part 10 of any one of the above items and the wafer supporting base 20 of any one of the above items, and the total number of pairs of axially extending peripheral surfaces 100 and radially extending end surfaces 200 of the wafer supporting base 20 that are bonded to the annular part 10 is greater than or equal to four pairs.

[0106] By providing the bottom of the annular member 10 of the bearing assembly and the wafer bearing base 20 with a total number of pairs of axially extending peripheral surfaces 100 and radially extending end surfaces 200 corresponding to the wafer bearing base 20 being greater than or equal to four pairs, the number and area of ​​the bonding surfaces can be increased. When the process is in progress, H2, as a gas that rotates the wafer bearing base 20, may enter the back of the wafer 30. Therefore, by increasing the number of contact surfaces between the annular member 10 and the wafer bearing base 20, H2 flowing from the bottom to the top is prevented from entering the back of the wafer 30, thereby reducing the total amount of H2 on the back of the wafer 30. Therefore, the degree to which the back of the wafer 30 is etched by H2 can be reduced.

[0107] Embodiment 4:

[0108] The fourth embodiment of the present invention provides a process chamber, which includes a cavity and the above-mentioned supporting assembly, and the supporting assembly is arranged in the cavity.

[0109] By arranging the above-mentioned supporting assembly in the process chamber, the process chamber accordingly has all the advantages of the above-mentioned supporting assembly, which will not be described one by one here.

[0110] Although the utility model is disclosed as above, the utility model is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the scope defined by the claims.

[0111] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0112] In the above embodiments, the descriptions of directions such as “upper” and “lower” are all based on the drawings.

[0113] The above description of the disclosed embodiments enables professionals in the field to implement or use the utility model. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility model.

[0114] Therefore, the present invention will not be limited to the embodiments shown herein but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ring-shaped member, used to cooperate with a wafer supporting base (20), characterized in that: The total number of the axially extending peripheral surface (100) and the radially extending end surface (200) of the bottom of the annular member (10) that are used to correspondingly fit with the wafer supporting base (20) is greater than or equal to four.

2. The ring member according to claim 1, characterized in that: The annular member (10) is provided with a radial inner flange (15), and the lower surface of the annular member (10) is provided with a first radial extension portion (16) and an annular lower flange (19), and the annular lower flange (19) is located on the outer side of the first radial extension portion (16); the lower surface of the radial inner flange (15), the portion of the inner circumference of the annular member (10) located below the radial inner flange (15), the first radial extension portion (16) and the inner circumference of the annular lower flange (19) are configured to fit with the wafer supporting base (20).

3. The ring member according to claim 2, characterized in that: The annular member (10) is further provided with a second radial extension portion (17), the second radial extension portion (17) being located between the first radial extension portion (16) and the annular lower flange (19), and a transition portion being provided between the second radial extension portion (17) and the first radial extension portion (16); the transition portion and the second radial extension portion (17) being configured to both fit the wafer supporting base (20).

4. The ring member according to claim 3, characterized in that: The height difference between the first radially extending portion (16) and the second radially extending portion (17) is 0.2 mm to 1.5 mm.

5. The ring member according to claim 1, characterized in that: The upper surface of the annular member (10) is provided with a third radial extension portion (11), and the third radial extension portion (11) is connected to the inner edge (12) and the outer edge (13) of the annular member (10) via an arc chamfer (14), and the arc chamfer (14) and the third radial extension portion (11), the inner edge (12) and the outer edge (13) are smoothly transitioned.

6. The ring member according to claim 5, characterized in that: The radius of the arc chamfer (14) is 0.1 mm to 3 mm.

7. The ring member according to claim 5, characterized in that: When the annular member (10) carries a wafer (30), the third radially extending portion (11) is configured to have a height consistent with an upper surface of the wafer (30).

8. The ring member according to claim 1, characterized in that: A plurality of positioning pins (18) are provided on the lower surface of the annular member (10), and the positioning pins (18) are configured to match positioning holes (23) provided on the wafer supporting base (20).

9. The ring member according to any one of claims 1 to 8, characterized in that: The upper surface of the annular member (10) is provided with a silicon carbide coating.

10. A wafer supporting base, used to cooperate with a ring member (10) thereon, characterized in that: The total number of the axially extending peripheral surface (100) and the radially extending end surface (200) of the wafer supporting base (20) that are used to correspondingly fit the annular member (10) is greater than or equal to four.

11. The wafer supporting base according to claim 10, characterized in that: The upper surface of the wafer supporting base (20) is provided with an annular upper flange (21), the annular member (10) is provided with a radial inner flange (15), the top surface of the annular upper flange (21) can be fitted with the lower surface of the radial inner flange (15), and the outer peripheral surface of the annular upper flange (21) can be fitted with the inner peripheral surface of the annular member (10) located below the radial inner flange (15); The lower surface of the annular member (10) is provided with a first radial extension portion (16) and an annular lower flange (19), and the annular lower flange (19) is located outside the first radial extension portion (16); the wafer supporting base (20) can be fitted with the first radial extension portion (16) and the annular lower flange (19).

12. The wafer supporting base according to claim 11, characterized in that: The annular member (10) is also provided with a second radial extension portion (17), the second radial extension portion (17) is located between the first radial extension portion (16) and the annular lower flange (19), and a transition portion is provided between the second radial extension portion (17) and the first radial extension portion (16); the wafer supporting base (20) is configured to fit with the transition portion and the second radial extension portion (17).

13. The wafer supporting base according to claim 11 or 12, characterized in that: The upper surface of the wafer supporting base (20) also has a groove (22), the groove (22) is located radially inward of the annular upper flange (21), and the groove (22) is configured to be spaced apart from the wafer (30).

14. The wafer supporting base according to claim 13, characterized in that: The bottom of the groove (22) is configured to be 0.5 mm to 2.5 mm away from the bottom surface of the wafer (30); and / or the bottom of the groove (22) is configured to be 0.5 mm to 2.5 mm away from the upper surface of the radial inner flange (15).

15. The wafer supporting base according to claim 11 or 12, characterized in that: The wafer supporting base (20) is provided with a plurality of positioning holes (23), and the positioning holes (23) are configured to match positioning pins (18) provided on the ring member (10).

16. A load-bearing assembly, characterized in that: It comprises an annular part (10) according to any one of claims 1 to 9 and a wafer supporting base (20) according to any one of claims 10 to 15, wherein the total number of pairs of axially extending peripheral surfaces (100) and radially extending end surfaces (200) of the wafer supporting base (20) that are in contact with the annular part (10) is greater than or equal to four pairs.

17. A process chamber, characterized in that: The process chamber comprises a cavity and the supporting assembly of claim 16, wherein the supporting assembly is disposed in the cavity.

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