Support structure for epitaxial growth apparatus, epitaxial growth apparatus and epitaxial wafer

Abstract

A support structure for an epitaxial growth apparatus, an epitaxial growth apparatus and an epitaxial wafer. The support structure for an epitaxial growth apparatus comprises: a plurality of first support arms, which are used for supporting a susceptor of the epitaxial growth apparatus from below the susceptor, said susceptor being used for supporting a wafer thereon; and a plurality of second support arms, which are capable of moving in a vertical direction and used for supporting a wafer from below the wafer; the plurality of second support arms are arranged above the plurality of first support arms and correspond to the plurality of first support arms in the vertical direction, and the second support arms can be moved to come into contact with the corresponding first support arms over the entire longitudinal length of the second support arms.

Description

Support structures for epitaxial growth equipment, epitaxial growth equipment, and epitaxial wafers.

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410964402.7, filed in China on July 18, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of wafer epitaxial growth technology, specifically to a support structure for epitaxial growth equipment, epitaxial growth equipment, and epitaxial wafer. Background Technology

[0004] Epitaxial growth is a process that uses chemical vapor deposition to grow an epitaxial film on a substrate wafer to obtain an epitaxial wafer. Epitaxial wafers have characteristics such as fewer surface defects, excellent crystallinity, and controllable resistivity. Epitaxial growth is usually carried out in an epitaxial furnace. In the epitaxial growth process, the substrate wafer to be epitaxially grown is first placed on a base in the reaction chamber of the epitaxial furnace. Then, a raw material gas is introduced into the process chamber. Under the high-temperature environment of the epitaxial furnace, the raw material gas flows over the surface of the substrate wafer and forms an epitaxial film on it.

[0005] Resistivity, as an important parameter for measuring the electrical performance of epitaxial wafers, is closely related to the epitaxial growth process conditions, especially the temperature conditions within the epitaxial furnace. However, due to factors such as the internal structural design of the epitaxial furnace, the thermal environment within the furnace may exhibit uneven temperature distribution, resulting in uneven heating of the substrate wafer as a whole. This leads to poor resistivity uniformity across the entire epitaxial wafer, adversely affecting its quality. Summary of the Invention

[0006] This section provides a general summary of the application, rather than a full disclosure of the entire scope or all features of the application.

[0007] The purpose of this application is to provide a support structure for an epitaxial growth device and an epitaxial growth device that can improve the overall heating uniformity of a wafer.

[0008] The purpose of this application is to provide a support structure for epitaxial growth equipment and an epitaxial growth equipment that can improve the resistivity uniformity of epitaxial wafers.

[0009] To achieve the above objectives, according to a first aspect of this application, a support structure for an epitaxial growth apparatus is provided, comprising:

[0010] Multiple first support arms, multiple first support arms for supporting a base below a pedestal of an epitaxial growth apparatus for supporting a wafer thereon; and

[0011] Multiple second support arms are movable in the vertical direction and used to support the wafer from below. The multiple second support arms are disposed above and correspond to the multiple first support arms in the vertical direction, and the second support arms are movable to contact the corresponding first support arm along the entire longitudinal length of the second support arm.

[0012] In some embodiments, each first support arm may include a first arcuate surface, each second support arm may include a second arcuate surface, and when the first support arm and the corresponding second support arm come into contact, the first arcuate surface and the second arcuate surface cooperate to form a cylindrical surface.

[0013] In some embodiments, one of the first support arm and the corresponding second support arm may include a protrusion and the other may include a recess, and the first support arm and the corresponding second support arm can form contact through the cooperation of the protrusion and the recess.

[0014] In some implementations, each second support arm may include an arm portion and a pin portion, the pin portion being integral with the arm portion and extending in a vertical direction to provide support for the wafer.

[0015] In some embodiments, the support structure for the epitaxial growth apparatus may further include a driving member for driving a plurality of second support arms such that the plurality of second support arms exert a downward force in a vertical direction on the plurality of first support arms when the plurality of second support arms come into contact with the plurality of first support arms, wherein the force is greater than the weight of the plurality of second support arms.

[0016] In some implementations, the second support arm may be a solid structure.

[0017] In some embodiments, the support structure for the epitaxial growth apparatus may further include a first support column and a second support column, a plurality of first support arms extending outward from the first support column as the center, a plurality of second support arms extending outward from the second support column as the center, both the first support column and the second support column extending in a vertical direction, and the second support column being coaxially arranged inside the first support column in a liftable manner.

[0018] In some embodiments, the support structure for the epitaxial growth apparatus may further include a retaining member configured to hold the relative positions of the first support column and the second support column in the horizontal direction fixed.

[0019] In some embodiments, the retaining member may be a rolling bearing disposed between the first support column and the second support column and in horizontal contact with the first support column and the second support column.

[0020] According to a second aspect of this application, an epitaxial growth apparatus is provided, comprising:

[0021] A base for supporting a wafer thereon; and

[0022] Support structure for epitaxial growth equipment according to the first aspect of this application.

[0023] According to a third aspect of this application, an epitaxial wafer is provided, which is obtained using an epitaxial growth apparatus according to a second aspect of this application, wherein the uniformity value of the epitaxial wafer is less than 4.08%, and the uniformity value is the ratio of the difference between the maximum and minimum resistivity values ​​measured at a plurality of points on the diameter of the epitaxial wafer and the sum of the maximum and minimum resistivity values.

[0024] In some implementations, the uniformity value of the epitaxial wafer can be less than 3%.

[0025] According to the above technical solution, by using the first support arm to shield the second support arm on the side away from the lower heat source, the second support arm is prevented from obstructing the propagation path of some radiant heat, thereby improving the overall heating uniformity of the wafer and thus enhancing the resistivity uniformity of the epitaxial wafer. Furthermore, by making the first and second support arms in contact, the gap between them is eliminated, effectively avoiding the adverse effects of the gap on heat transfer. This allows radiant heat to be transferred to the wafer with less obstruction and loss, further improving the overall heating uniformity of the wafer and the resistivity uniformity of the epitaxial wafer. Attached Figure Description

[0026] The features and advantages of embodiments of this application will become more readily understood from the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show details of specific components. In the drawings:

[0027] Figure 1 shows a schematic diagram of an epitaxial growth apparatus according to related technologies.

[0028] Figure 2 shows the resistivity distribution of the epitaxial wafer obtained using the epitaxial growth equipment in Figure 1.

[0029] Figure 3 shows the radial resistivity variation curve of the epitaxial wafer obtained using the epitaxial growth equipment in Figure 1.

[0030] Figure 4 shows a schematic diagram of a support structure for an epitaxial growth apparatus according to an embodiment of this application.

[0031] Figure 5 shows a partial schematic diagram of the first support arm and the second support arm in contact state according to an embodiment of this application.

[0032] Figure 6 shows a partial schematic diagram of the first support arm and the second support arm in a non-contact state according to an embodiment of the present application.

[0033] Figure 7 shows a cross-sectional view of the first support arm and the second support arm in contact state according to the embodiment of this application, obtained along the dashed line AA of Figure 5.

[0034] Figure 8 shows a cross-sectional view of the first support arm and the second support arm in contact state according to another embodiment of the present application, obtained along the dashed line AA of Figure 5.

[0035] Figure 9 shows a cross-sectional view of the first support arm and the second support arm in a non-contact state, obtained along the dashed line BB of Figure 6 according to another embodiment of the present application.

[0036] Figure 10 shows a schematic diagram of an epitaxial growth apparatus according to an embodiment of this application.

[0037] Figure 11 shows a comparison between the radial resistivity variation curve of an epitaxial wafer obtained using the epitaxial growth apparatus of Figure 1 and the radial resistivity variation curve of an epitaxial wafer obtained using the epitaxial growth apparatus according to an embodiment of this application.

[0038] In the accompanying drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. Detailed Implementation

[0039] The present application will now be described in detail with reference to the accompanying drawings and exemplary embodiments. It should be noted that the following detailed description of the present application is for illustrative purposes only and is not intended to limit the scope of the application.

[0040] First, with reference to Figures 1 to 3, the problems in the background art of this application will be explained in detail.

[0041] Figure 1 illustrates an epitaxial growth apparatus 1 according to related art. The epitaxial growth apparatus 1 includes: an upper quartz bell jar 2 and a lower quartz bell jar 3, which substantially define the reaction chamber for epitaxial growth; an inlet 4 and an outlet 5, which respectively allow process gases to enter and exit the reaction chamber; an upper lamp assembly 6 and a lower lamp assembly 7, which serve as heat sources to provide the high temperatures required for epitaxial growth; a base 8 for supporting the wafer; and a support structure 9 for supporting the base 8 and rotating the base 8 during epitaxial growth. The support structure 9 includes a base support portion 91 for supporting the base 8, a lifting pin 92 for supporting the wafer, and a lifting pin support portion 93 for supporting the lifting pin 92. The lifting pin support portion 93 is located below the base support portion 91 and is movable vertically to move the lifting pin 92 vertically.

[0042] In preparation for the epitaxial growth process, the wafer is first conveyed into the reaction chamber and contacted and supported by the lifting pin 92 in the rising position. Subsequently, as the lifting pin 92 moves to the falling position, the wafer is supported on the base 8. After the wafer is in place, process gas is introduced into the reaction chamber through the gas inlet 4, heated by the upper lamp group 6 and the lower lamp group 7. The support structure 9 drives the base 8 and the wafer to rotate, so that the process gas flows evenly across the wafer surface for epitaxial growth.

[0043] Figure 2 shows the resistivity distribution of an epitaxial wafer with a diameter of 300 mm obtained using the epitaxial growth apparatus 1 described above. As shown, a significant color difference exists between the annular region approximately R / 2 from the center of the epitaxial wafer and other regions, indicating that the resistivity of the entire epitaxial wafer is not uniform across different areas. This annular region corresponds to the area shielded by the lifting pin support 93.

[0044] Figure 3 shows the radial resistivity variation curve of an epitaxial wafer with a diameter of 300 mm obtained using the epitaxial growth apparatus 1 described above, where the horizontal axis represents the diameter and the vertical axis represents the resistivity. As shown in the figure, the resistivity is relatively high in a region approximately R / 2 from the center of the epitaxial wafer (especially in the range of -100 mm to 100 mm in diameter), which corresponds to the area shielded by the lifting pin support 93.

[0045] The following is a detailed analysis of the causes of the aforementioned problem of non-uniform resistivity in epitaxial wafers.

[0046] In the aforementioned epitaxial growth apparatus 1, since the lifting pin support 93 is closer to the lower lamp group 7 than the base support 91, some of the radiant heat generated by the lower lamp group 7 will pass through the lifting pin support 93 before passing through the base support 91 when it is transferred to the wafer. This causes some radiant heat to be unable to propagate to the back of the lifting pin support 93 due to reasons such as reflection or refraction. As a result, the temperature of the area of ​​the wafer shielded by the lifting pin support 93 is lower than the temperature of other areas, which in turn causes uneven heating of the wafer over its entire area, resulting in inconsistent resistivity of the epitaxial wafer as a whole.

[0047] To address the aforementioned problems, referring to Figures 4 to 10, according to an embodiment of this application, a support structure 100 for an epitaxial growth apparatus is provided. The epitaxial growth apparatus includes a base 200 for supporting a wafer W thereon. The support structure 100 includes a plurality of first support arms 110 and a plurality of second support arms 120. As shown in Figure 4, the plurality of first support arms 110 and the plurality of second support arms 120 may be located below the base 200. The first support arms 110 and the second support arms 120 may have elongated rod-like structures. The plurality of first support arms 110 may extend radially from their respective proximal ends to their distal ends from the same center. The plurality of second support arms 120 may extend from their respective proximal ends to their distal ends in a similar manner. Here, the distal end refers to the end away from the center of the base 200, and the proximal end refers to the end close to the center of the base 200.

[0048] Multiple first support arms 110 are used to support the base 200 from below. As shown in FIG4, each first support arm 110 may include, for example, a support portion located at its distal end, for providing support at, for example, the periphery of the base 200. It is understood that, depending on the needs of the epitaxial growth process, the multiple first support arms 110 may also be used to drive the base 200 to rotate so that the wafer can grow epitaxially uniformly.

[0049] Multiple second support arms 120 are used to support the wafer from below. As shown in FIG. 4, each second support arm 120 may include, for example, a support portion located at its distal end for providing support at, for example, the periphery of the wafer W. The multiple second support arms 120 are movable in a vertical direction. Specifically, the multiple second support arms 120 are movable in a vertical direction between their raised and lowered positions. For example, when a wafer needs to be placed into the epitaxial growth apparatus, the second support arm 120 is in its raised position, at which time the support portion of the second support arm 120 protrudes above the base 200, for example, through a through-hole in the base 200, to receive the wafer. Subsequently, the second support arm 120 and its support portion move to the lowered position to place the wafer on the base 200 for epitaxial growth.

[0050] Multiple second support arms 120 are disposed above and vertically correspond to multiple first support arms 110. Specifically, each second support arm 120 corresponds one-to-one with a first support arm 110. Each second support arm 120 is located directly above its corresponding first support arm 110 and aligned vertically with each other. That is, each second support arm 120 and its corresponding first support arm 110 are substantially on the same vertical plane, so that when viewed vertically upwards, the second support arm 120 can be obscured by its corresponding first support arm 110. It should be understood that the second support arm 120 can rotate synchronously with the first support arm 110 when the base 200 is rotated by the first support arm 110.

[0051] In this scenario, when the radiant heat generated by the lower heat source propagates upwards to the upper wafer, the second support arm is shielded by the first support arm on the side facing away from or away from the lower heat source. This prevents the second support arm from obstructing the propagation of radiant heat, ensuring that the temperature of the area of ​​the wafer corresponding to the second support arm remains consistent with the temperature of other areas. This improves the overall heating uniformity of the wafer and enhances the uniformity of the resistivity of the epitaxial wafer.

[0052] The second support arm 120 is movable to contact the corresponding first support arm 110 along its entire longitudinal length. Specifically, the second support arm 120 is able to form this contact when it is moved to its lowered position. Here, the “longitudinal length” of the first support arm 110 and the second support arm 120 refers to their respective lengths from proximal to distal ends. It should be particularly understood that the contact is not merely contact at certain points or along a portion of the longitudinal length of the second support arm 120.

[0053] For example, as shown in Figures 7 and 8, the second support arm 120 may have a lower surface 125, and the first support arm 110 may have an upper surface 115. When the first support arm 110 and the second support arm 120 form the aforementioned contact, the entire lower surface 125 of the second support arm 120 achieves gapless contact and fit with the corresponding area of ​​the upper surface 115 of the first support arm 110 (the shaded area at the contact interface in Figures 7 and 8 is used to indicate the boundary line between the first support arm 110 and the second support arm 120).

[0054] This design eliminates the gap between the first support arm 110 and the second support arm 120, effectively avoiding adverse effects such as local overheating or heat loss caused by the gap on heat transfer. This allows radiant heat to propagate to the wafer with less obstruction and loss, thereby further improving the overall heating uniformity of the wafer and thus improving the resistivity uniformity of the epitaxial wafer.

[0055] It is understandable that, as shown in Figure 4, the longitudinal length of the second support arm 120 can be less than the longitudinal length of the first support arm 110, but it is not limited to this. The specific length can be set according to the size of the base and the wafer.

[0056] It is conceivable that the support structure 100 may include at least three first support arms 110 and at least three second support arms 120. It is also conceivable that the multiple first support arms 110 and multiple second support arms 120 may be evenly distributed in the circumferential direction.

[0057] In some embodiments, each first support arm 110 may include a first arcuate surface 111, and each second support arm 120 may include a second arcuate surface 121. When the first support arm 110 and the corresponding second support arm 120 come into contact, the first arcuate surface 111 and the second arcuate surface 121 cooperate to form a cylindrical surface.

[0058] Specifically, the second arcuate surface 121 extends along the entire longitudinal length of the second support arm 120, and the shape of any cross-section of the second support arm 120 along its longitudinal length is the second arcuate shape. The first arcuate surface 111 extends at least along the longitudinal length of the first support arm 110 corresponding to the second support arm 120, and the shape of any cross-section of the first support arm 110 along that corresponding longitudinal length is the first arcuate shape. The first and second arcuate shapes are geometrically complementary, allowing them to fit together to form a complete circle.

[0059] For example, as shown in Figures 7 and 8, the first support arm 110 may include a lower surface with a semi-circular cross-section, and the second support arm 120 may include an upper surface with a semi-circular cross-section. When the two come into contact, the two semi-circular surfaces align with each other and form a cylindrical surface with a circular cross-section.

[0060] By making the overall structure formed by the first support arm 110 and the second support arm 120 have a cylindrical surface, the continuous and smooth convex surface can promote the dissipation of radiative heat and avoid the convergence of radiative heat, so that the heat can be radiated more evenly to the surrounding space. This can further improve the overall heating uniformity of the wafer and help improve the uniformity of the resistivity of the epitaxial wafer.

[0061] It should be understood that there are no restrictions on the curvature of the first arc surface 111 and the curvature of the second arc surface 121, as long as the sum of the two equals the curvature of a complete circle.

[0062] In some embodiments, as shown in FIG9, one of the first support arm 110 and the corresponding second support arm 120 may include a recess 112 and the other may include a protrusion 122, and the first support arm 110 and the corresponding second support arm 120 can form contact through the cooperation of the recess 112 and the protrusion 122.

[0063] Specifically, the recess 112 and the convex portion 122 have complementary shapes and are aligned with each other in the vertical direction, allowing them to fit together without gaps or with substantially no gaps. With the recess 112 and the convex portion 122 engaged, the first support arm 110 and the corresponding second support arm 120 make contact at least in the corresponding areas of the recess 112 and the convex portion 122.

[0064] For example, as shown in FIG9, the first support arm 110 may include a recess 112 in its upper part, and the second support arm 120 may include a protrusion 122 in its lower part. When the second support arm 120 descends, the protrusion 122 moves downward and engages with the recess 112. When the second support arm 120 rises, the protrusion 122 moves upward and disengages from the recess 112. It should be understood that the shapes of the recess 112 and the protrusion 122 are not limited to the square shape shown in FIG9, but only need to be complementary in shape.

[0065] The cooperation of the recess 112 and the protrusion 122 enables the first support arm 110 and the second support arm 120 to be horizontally locked, thus keeping their relative positions in the horizontal direction fixed. When the first support arm 110 drives the base 200 to rotate, the first support arm 110 and the second support arm 120 can rotate together as a whole without relative sliding or separation, effectively improving their stability during rotation.

[0066] Furthermore, the recess 112 and the protrusion 122 also serve as vertical guides for the contact between the first support arm 110 and the second support arm 120. In particular, when the first arcuate surface 111 and the second arcuate surface 121 mate, this vertical guide helps ensure that the first arcuate surface 111 and the second arcuate surface 121 are accurately aligned and mate to form a smooth cylindrical surface.

[0067] In some embodiments, each second support arm 120 may include an arm portion 123 and a pin portion 124, the pin portion 124 being integral with the arm portion 123 and extending in a vertical direction to provide support for the wafer.

[0068] The pin 124 and the arm 123 can be integrally formed, for example, through casting, forging, welding, bonding, or other manufacturing processes. This integrated design allows the arm 123 and the pin 124 to move vertically as a single unit. Compared to a separate design, this eliminates the need to align the arm 123 and the pin 124 separately, thereby simplifying the operation and improving movement stability and consistency. Furthermore, this integrated design reduces the number of parts that need to be individually installed or aligned, thus saving assembly time and avoiding assembly errors.

[0069] In some embodiments, the support structure 100 for the epitaxial growth apparatus may further include a drive member 150 for driving a plurality of second support arms 120 such that the plurality of second support arms 120 apply a downward force in a vertical direction to the plurality of first support arms 110 when the plurality of second support arms 120 come into contact with the plurality of first support arms 110, wherein the force is greater than the weight of the plurality of second support arms 120.

[0070] Specifically, under the driving action of the driving member 150, when the plurality of second support arms 120 come into contact with the plurality of first support arms 110, the downward vertical force exerted by the plurality of second support arms 120 on the contact surfaces of the plurality of first support arms 110 comes from the weight of the plurality of second support arms 120 themselves and an additional force provided by the driving member 150 to the plurality of second support arms 120. This additional force is a downward vertical force or a downward vertical force component exerted by the driving member 150 on the second support arms 120, which is transmitted to the contact surfaces of the first support arms 110 through the contact between the second support arms 120 and the first support arms 110.

[0071] Under the force greater than its own weight, the second support arm 120 can make close contact with and press against the first support arm 110. In this case, not only is the equivalent center of gravity of the two effectively lowered, but the friction between the contact surfaces is also increased by increasing the contact pressure, thereby increasing the rotational stability of the two. For example, this helps to suppress or reduce the offset that may be caused by the high center of gravity of the overall structure during the rotation of the base 200 driven by the first support arm 110, thereby effectively preventing the base 200 and the wafer from deviating from the center position, ensuring the uniformity of epitaxial layer growth, and avoiding the deterioration of the flatness of the epitaxial wafer.

[0072] It is understood that the drive component 150 may be a push rod, pull rod, lead screw, magnetic component, or other component suitable for applying a vertically downward driving force.

[0073] In some embodiments, the second support arm 120 can be a solid structure. For example, the second support arm 120 can be a solid structure formed of a material with high density or weight, such as metal, quartz, or graphite. Therefore, the weight of the second support arm 120 can be relatively greater, so that when multiple second support arms 120 come into contact with multiple first support arms 110, the center of gravity of the overall structure formed by the two can be relatively lower, which is beneficial to improving the balance and rotational stability of the overall structure.

[0074] In some embodiments, the support structure 100 for the epitaxial growth apparatus may further include a first support column 130 and a second support column 140, a plurality of first support arms 110 extending outward from the first support column 130 as the center, a plurality of second support arms 120 extending outward from the second support column 140 as the center, the first support column 130 and the second support column 140 both extending in a vertical direction, and the second support column 140 being coaxially arranged inside the first support column 130 in a liftable manner.

[0075] For example, as shown in FIG4, the first support column 130 and the second support column 140 may have an elongated cylindrical structure, and their central axes may be collinear with the center of the base 200. A plurality of first support arms 110 may extend, for example, at the upper end of the first support column 130. Similarly, a plurality of second support arms 120 may extend, for example, at the upper end of the second support column 140. The first support column 130 may have a hollow portion for receiving the second support column 140, the hollow portion being open at the top to allow the second support column 140 to move vertically.

[0076] The second support column 140 can form an integral structure with multiple second support arms 120, so that the lifting and lowering of the second support column 140 can drive the lifting and lowering of the multiple second support arms 120, thereby realizing the lifting and lowering of the wafer as needed. The first support column 130 can form an integral structure with multiple first support arms 110, so that the rotation of the first support column 130 around its central axis can drive the rotation of the multiple first support arms 110, thereby realizing the rotation of the base 200 and the wafer.

[0077] It is conceivable that the second support column 140 may be equipped with a lifting drive mechanism, which may include, for example, a motor and a lead screw. The first support column 130 may be equipped with a rotary drive mechanism, which may include a motor and a rotating shaft.

[0078] In some embodiments, the support structure 100 for the epitaxial growth apparatus may further include a retaining member 160 configured to hold the relative positions of the first support column 130 and the second support column 140 in the horizontal direction fixed.

[0079] It should be understood that the retaining member 160 is configured to hold the relative positions of the first support column 130 and the second support column 140 in the horizontal direction fixed without affecting the lifting and lowering of the second support column 140. Exemplarily, the retaining member 160 may be configured to hold the first support column 130 or the second support column 140, or a combination thereof, in the horizontal direction, and may include, for example, a limiting member, a guide rail and a slider mechanism, and other suitable components capable of restricting horizontal movement while allowing vertical movement of the second support column 140.

[0080] By setting the retaining member 160 to prevent the first support column 130 and the second support column 140 from moving relative to each other in the horizontal direction, the stability of the overall structure formed by the two is improved, making the first support column 130 less likely to deviate when rotating.

[0081] In some embodiments, the retaining member 160 may be a rolling bearing disposed between the first support column 130 and the second support column 140 and in horizontal contact with the first support column 130 and the second support column 140. In this case, there is less friction between the rolling element of the rolling bearing and the second support column 140, which facilitates the smooth and stable raising and lowering of the second support column 140.

[0082] According to an embodiment of this application, as shown in FIG10, an epitaxial growth apparatus 10 is also provided, including a support structure 100 as described in any of the foregoing embodiments, and a base 200 for supporting a wafer thereon. The epitaxial growth apparatus 10 may further include an upper quartz bell jar 300, a lower quartz bell jar 400, an air inlet 500 and an air outlet 600, an upper lamp assembly 700 and a lower lamp assembly 800.

[0083] According to an embodiment of this application, an epitaxial wafer is also provided, which is obtained using an epitaxial growth apparatus according to an embodiment of this application. The uniformity value of this epitaxial wafer is less than 4.08%. The uniformity value is the ratio of the difference between the maximum and minimum resistivity values ​​measured at multiple points along the diameter of the epitaxial wafer to the sum of the maximum and minimum resistivity values. That is, uniformity value = (maximum value - minimum value) / (maximum value + minimum value). The smaller the uniformity value, the better the resistivity uniformity.

[0084] As shown below, Table 1 shows the resistivity measured at 35 test points along the diameter of an epitaxial wafer obtained using the epitaxial growth apparatus of Figure 1 (comparative example) (hereinafter referred to as the first epitaxial wafer) and an epitaxial wafer obtained using the epitaxial growth apparatus according to an embodiment of this application (example) (hereinafter referred to as the second epitaxial wafer). Table 2 shows the statistical results of the data in Table 1.

[0085] Table 1

[0086] Table 2

[0087] As shown in Table 2, the maximum resistivity of the first epitaxial wafer across 35 test points on its diameter is 10.47 ohms·cm, and the minimum is 9.65 ohms·cm, resulting in a uniformity value of 4.08%. The uniformity value of the second epitaxial wafer is less than that of the first epitaxial wafer, i.e., less than 4.08%. More specifically, the uniformity value obtained by the second epitaxial wafer can be less than 3%. Specifically, the maximum resistivity of the second epitaxial wafer across 35 test points on its diameter is 10.22 ohms·cm, and the minimum is 9.68 ohms·cm, resulting in a uniformity value of 2.71%.

[0088] Figure 11 shows the resistivity variation curve C1 of the first epitaxial wafer along its diameter obtained in the comparative example, and the resistivity variation curve C2 of the second epitaxial wafer along its diameter obtained in the embodiment. Curves C1 and C2 in Figure 11 are plotted based on the data results in Table 1, where the horizontal axis represents the position corresponding to the measurement point, and the vertical axis represents the resistivity value corresponding to the measurement point.

[0089] As shown in Figure 11, compared with the resistivity variation curve of the central region of the first epitaxial wafer (especially the region with a diameter of -70mm to 70mm), the resistivity variation curve of the corresponding central region of the second epitaxial wafer is flatter, and the overall resistivity value is relatively lower.

[0090] The above results all demonstrate that by employing the epitaxial growth equipment according to the embodiments of this application, the resistivity uniformity of epitaxial wafers can be effectively improved, thereby enhancing the quality of epitaxial wafers.

[0091] Although this application has been described with reference to exemplary embodiments, it should be understood that this application is not limited to the specific embodiments described and shown herein. Various changes can be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims of this application.

[0092] The features mentioned and / or shown in the above description of exemplary embodiments of this application can be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. These combined or substituted technical solutions should also be considered to be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A support structure for an epitaxial growth apparatus, comprising: a plurality of first support arms for supporting a susceptor of the epitaxial growth apparatus from below for supporting a wafer thereon; and a plurality of second support arms movable in a vertical direction and for supporting the wafer from below, the plurality of second support arms being disposed above and corresponding to the plurality of first support arms in the vertical direction, and the second support arms being movable into contact with the corresponding first support arms over an entire longitudinal length of the second support arms.

2. The support structure for epitaxial growth equipment of claim 1, wherein, Each of the first support arms includes a first arcuate surface, each of the second support arms includes a second arcuate surface, and the first arcuate surface cooperates with the second arcuate surface to form a cylindrical surface when the first support arms and the corresponding second support arms form the contact.

3. A support structure for epitaxial growth equipment according to claim 1 or 2, wherein, One of the first support arms and the corresponding second support arms includes a convex portion, and the other includes a concave portion, the first support arms and the corresponding second support arms being capable of forming the contact by cooperation of the convex portion and the concave portion.

4. The support structure for epitaxial growth equipment of claim 1, wherein, Each of the second support arms includes an arm portion and a pin portion formed integrally with the arm portion and extending in a vertical direction for providing support for the wafer.

5. The support structure for epitaxial growth equipment of claim 1, wherein, Further comprising a drive member for driving the plurality of second support arms such that the plurality of second support arms exert a force downward in the vertical direction on the plurality of first support arms when the plurality of second support arms form the contact with the plurality of first support arms, wherein the force is greater than a gravitational force of the plurality of second support arms.

6. The support structure for epitaxial growth equipment of claim 1, wherein, The second support arms are of a solid structure.

7. The support structure for epitaxial growth equipment of claim 1, wherein, Further comprising a first support column and a second support column, the plurality of first support arms extending outwardly with the first support column as a center, the plurality of second support arms extending outwardly with the second support column as a center, the first support column and the second support column each extending in a vertical direction, and the second support column being coaxially disposed inside the first support column in a liftable manner.

8. A support structure for epitaxial growth equipment according to claim 7, wherein, Further comprising a holding member configured to hold a relative position of the first support column and the second support column in a horizontal direction fixed.

9. A support structure for epitaxial growth equipment according to claim 8, wherein, The holding member is a rolling bearing disposed between the first support column and the second support column and in contact with the first support column and the second support column in the horizontal direction. 10.An epitaxial growth apparatus, comprising: a susceptor for supporting a wafer thereon; and a support structure for an epitaxial growth apparatus according to any one of claims 1 to 9. 11.An epitaxial wafer obtained using the epitaxial growth apparatus according to claim 10, the epitaxial wafer having a uniformity value of less than 4.08%, the uniformity value being a ratio of a difference between a maximum value and a minimum value of resistivity measured for a plurality of points on a diameter of the epitaxial wafer and a sum of the maximum value and the minimum value. The uniformity value is less than 3%.

12. The epitaxial wafer of claim 11, wherein, ​

Images