TW202303814A - Base supporting frame, device and method for epitaxial growth of silicon wafer - Google Patents

Abstract

The embodiment of the invention discloses a base supporting frame, a device and a method for epitaxial growth of a silicon wafer. The base supporting frame comprises: four base supporting arms, which extend outwards in a radial direction and extend upwards in an axial direction from the longitudinal axis of the base supporting frame, wherein the four base supporting arms are evenly distributed in a circumferential direction around the longitudinal axis, and the far end parts of the four base supporting arms support a base used for bearing the silicon wafer together; and four concave lenses, which are respectively connected to the four base supporting arms, wherein each concave lens extends along the connected base supporting arm, the four concave lenses are arranged in a manner that four <110> crystal orientations corresponding to the silicon wafer borne in the base are respectively aligned with the four base supporting arms in a vertical direction, and radiant heat radiated to four <110> crystal orientation positions of the silicon wafer through the four concave lenses in a vertical direction can be refracted and diffused by the four concave lenses.

Description

A base support frame, device and method for epitaxial growth of silicon wafers

Embodiments of the present invention belong to the technical field of epitaxial growth of silicon wafers, and in particular relate to a base supporting frame, device and method for epitaxial growth of silicon wafers.

The epitaxial growth technology of silicon wafer is an important technology in the semiconductor wafer manufacturing process. This technology refers to growing a layer of crystal-originated particles (Crystal Originated Particles, COP) defect and oxygen-free precipitated silicon single crystal layer. The epitaxial growth of silicon wafers mainly includes growth methods such as vacuum epitaxial deposition, vapor phase epitaxial deposition, and liquid phase epitaxial deposition, among which vapor phase epitaxial deposition is the most widely used. If not otherwise stated, the epitaxial growth mentioned in the present invention refers to the epitaxial growth accomplished by vapor phase epitaxial deposition.

For the epitaxial growth of silicon wafers, flatness is an important index to measure the quality of epitaxial silicon wafers, and the flatness of epitaxial silicon wafers is directly related to the thickness of the epitaxial layer. During the epitaxial growth process, the temperature in the reaction chamber generated by the heating bulb, the concentration of the silicon source gas, and the flow rate of the silicon source gas will have a very obvious impact on the thickness of the epitaxial layer. In addition, the crystal orientation of the silicon wafer is another important factor affecting the thickness of the epitaxial layer and thus the flatness of the epitaxial silicon wafer. The following is a detailed introduction to the crystal orientation of the silicon wafer and the influence of the crystal orientation on the thickness of the epitaxial layer.

Referring to Fig. 1, Fig. 1 shows the crystal orientation of the silicon wafer by taking the silicon wafer W100 of the (100) crystal plane as an example. As shown in Figure 1, if the three o'clock direction of the silicon wafer W100 is the radial direction of 0°/360° and is the <110> crystal orientation, then the clockwise rotation relative to the radial direction of 0°/360° The radial directions of 90°, 180° and 270° are also the <110> crystal orientation of silicon wafer W100, while the 45°, 135°, 225° and 315 The radial direction of ° is the <100> crystal orientation of the silicon wafer W100. That is to say, for the silicon wafer W100, the four <110> crystal directions correspond to the four radial directions distributed at 90° intervals along the circumference of the silicon wafer, and the four <100> crystal directions also correspond to the four radial directions along the silicon wafer. The four radial directions distributed at intervals of 90° in the circumferential direction of the wafer correspond to each other, and the adjacent <110> crystal directions and <100> crystal directions are separated by 45° along the circumferential direction of the silicon wafer.

Referring to FIG. 2 , it shows a silicon wafer W100 having a diameter of 300 mm as shown in FIG. Edge Site Frontsurface-referenced least sQuares/Range (ESFQR) results. In FIG. 2, the abscissa represents the angle in the radial direction of the silicon wafer W100 shown in FIG. 1, and the ordinate represents the ESFQR value (unit: nm) of the silicon wafer W100 at the corresponding angular position. The ESFQR value can reflect the birth The thickness of the long epitaxial layer. As shown in Figure 2, in the radial direction of 0°/360°, 90°, 180° and 270°, the thickness of the epitaxial layer grown on the silicon wafer W100 is the peak value, that is to say, the thickness of the epitaxial layer grown on the silicon wafer W100 is <110 >The growth rate of the crystal orientation is the largest; from the radial direction of 0°, 90°, 180° and 270° to the radial direction of 45°, 135°, 225° and 315° and from the radial direction of 90°, 180°, 270° From the radial direction of 360° to the radial direction of 45°, 135°, 225° and 315°, the thickness of the epitaxial layer grown on the silicon wafer W100 decreases gradually, that is to say, the growth rate of the silicon wafer W100 changes from < The crystal orientation from 110> to <100> gradually decreases, which is also shown by the arrowed arc in Figure 1, where the arrow direction indicates the direction of growth rate decrease; at 45°, 135°, 225° and 315° In the radial direction of , the thickness of the epitaxial layer grown on the silicon wafer W100 is the valley value, that is to say, the growth rate of the silicon wafer W100 in the <100> crystal direction is the smallest, and as known in the related art, the above-mentioned thickness The difference is more pronounced closer to the radial edge of the wafer.

A related measure to improve the flatness of the epitaxial silicon wafer is to deliver the etching gas used to prevent the deposition of the epitaxial layer into the reaction chamber through the gas inlet, and during the rotation of the silicon wafer with the susceptor, As faster growing regions of the wafer pass through the gas inlet, the gas inlet rate increases, while as slower growing regions of the silicon wafer pass through the gas inlet, the gas inlet rate decreases. However, in the epitaxial growth process of silicon wafers, it is inevitable to change technical parameters such as the rotation speed of the susceptor. Complexity.

Another related measure to improve the flatness of the epitaxial silicon wafer is to add a heat conduction block to the bottom surface of the base to change the temperature of the corresponding area, so as to achieve the purpose of improving the flatness of the silicon wafer. However, since the thickness of the area where the heat conduction block is installed in the base is relatively small, usually less than 3mm, the installed heat conduction block will bring load bearing problems to the base, affecting the service life of the base. On the other hand, the heat conduction block will change the temperature of the corresponding area except its installation area, so that the local morphology of the finally obtained epitaxial silicon wafer will be affected, and in severe cases, dislocations will occur on the silicon wafer due to uneven stress.

In view of this, the embodiment of the present invention expects to provide a base support frame, device and method for epitaxial growth of silicon wafers; by changing the structure of the corresponding part of the base support frame and then changing the temperature distribution of the corresponding part of the silicon wafer to solve the problem The thickness of the epitaxial layer is not uniform during the epitaxial growth process due to the different crystal orientations of the silicon wafer, which leads to the problem of poor flatness of the epitaxial silicon wafer.

The technical scheme of the embodiment of the present invention is realized like this: In a first aspect, an embodiment of the present invention provides a pedestal support frame for epitaxial growth of a silicon wafer, wherein the pedestal support frame includes: Four base support arms extending radially outward and axially upward from the longitudinal axis of the base support frame, the four base support arms are evenly distributed in the circumferential direction around the longitudinal axis, the four base support arms the distal ends of the arms together support a base for carrying the wafer; The four concave lenses are respectively connected to the four base support arms, each concave lens extends along the connected base support arm, and the four concave lenses are arranged so as to correspond to the silicon chip carried in the base. The four <110> crystal directions are vertically aligned with the four pedestal support arms, and the radiant heat radiated to the positions of the four <110> crystal directions of the silicon wafer through the four concave lenses in the vertical direction can be is refracted and diverged by the four concave lenses.

In a second aspect, an embodiment of the present invention provides a device for epitaxial growth of a silicon wafer, characterized in that the device includes a disc-shaped base for carrying the silicon wafer; The base support frame according to the first aspect; an upper bell and a lower bell, the upper bell and the lower bell together enclosing a reaction chamber housing the base, wherein the base separates the reaction chamber into an upper reaction chamber and a lower reaction chamber chamber, the silicon wafer is placed in the upper reaction chamber; a plurality of heating bulbs arranged on the periphery of the upper quartz bell jar and the lower quartz bell jar and used to provide a high temperature environment for vapor phase epitaxy deposition in the reaction chamber through the upper bell jar and the lower bell jar; an air inlet, the air inlet is used to sequentially deliver cleaning gas and silicon source gas into the reaction chamber; an exhaust port, the exhaust port is used to discharge the respective reaction tail gases of the cleaning gas and the silicon source gas out of the reaction chamber.

In a third aspect, an embodiment of the present invention provides a method for epitaxial growth of a silicon wafer, the method is applied to the device according to the second aspect, and the method includes: supporting the silicon wafer in the susceptor so that the four <110> crystal orientations of the silicon wafer are respectively vertically aligned with the four susceptor support arms; Turning on the plurality of heating bulbs to increase the temperature of the reaction chamber to 1100° C. to 1150° C., and delivering silicon source gas into the upper reaction chamber through the gas inlet to grow an epitaxial layer on the silicon wafer; The silicon source gas passes through the front side of the silicon wafer from the upper reaction chamber, and diffuses to the back side of the silicon wafer and is exhausted from the gap of the reaction chamber into the lower reaction chamber, so that the silicon source gas grows on the silicon wafer. The thickness of the epitaxial layer is uniform; The reaction tail gas including the silicon source gas discharged into the lower reaction chamber is discharged from the reaction chamber through the exhaust port.

Embodiments of the present invention provide a base support frame, device and method for epitaxial growth of silicon wafers; the base support arms in the base support frame of epitaxial silicon wafers are changed from three to four, and each base Concave lenses are set on the support arms of the base, and the four <110> crystal directions of the silicon wafer are respectively aligned with the four base support arms in the vertical direction, so that the four <110> crystal directions of the silicon wafer are respectively radiated through the four concave lenses. The radiant heat at the position of the crystal direction can be refracted and diverged by four concave lenses, thereby reducing the temperature distribution of the <110> crystal direction of the silicon wafer. In this case, the growth rate of the entire circumference of the silicon wafer is more balanced. The thickness of the epitaxial layer grown on the silicon wafer is more uniform, so that an epitaxial silicon wafer with better flatness can be obtained.

In order for Ligui examiners to understand the technical characteristics, content and advantages of the present invention and the effects it can achieve, the present invention is hereby combined with the accompanying drawings and appendices, and is described in detail in the form of embodiments as follows, and the drawings used therein , the purpose of which is only for illustration and auxiliary instructions, and not necessarily the true proportion and precise configuration of the present invention after implementation, so it should not be interpreted based on the proportion and configuration relationship of the attached drawings, and limit the application of the present invention in actual implementation The scope is described first.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical ", "horizontal", "top", "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying Describes, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and operate in a specific orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In the embodiments of the present invention, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense unless otherwise clearly specified and limited. Disassembled connection, or integration; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those with ordinary knowledge in the art can understand the specific meanings of the above terms in the embodiments of the present invention according to specific situations.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

Referring to FIG. 3 , it shows a schematic diagram of a related apparatus 1 for epitaxial growth of a silicon wafer W. Referring to FIG. As shown in FIG. 3, the device 1 may include: a base 10, which is used to carry a silicon wafer W; a base support frame 20, which is used to support the base 10 and during epitaxial growth. The base 10 is driven to rotate around the central axis X at a certain speed, wherein during the rotation of the base 10, the silicon wafer W rotates with the base 10 around the central axis X, that is to say, the silicon wafer W is held relative to the base 10 Stationary, thus, requires a small gap G between the radial edge of the susceptor 10 and the adjacent part 10A (typically the preheating ring); an upper quartz bell 30A and a lower quartz bell 30B, the upper quartz bell 30A Together with the lower quartz bell jar 30B, the reaction chamber RC in which the base 10 and the base support frame 20 are accommodated is enclosed, wherein the base 10 separates the reaction chamber RC into an upper reaction chamber RC1 and a lower reaction chamber. chamber RC2, the silicon wafer W is placed in the upper reaction chamber RC1; usually, the air pressure in the upper reaction chamber RC1 is slightly greater than the air pressure in the lower reaction chamber RC2 so that the gas in the upper reaction chamber RC1 will enter through the gap G into the In the lower reaction chamber RC2; an air inlet 40, the air inlet 40 is used to transport reaction gas in the upper reaction chamber RC1, such as silicon source gas such as SiHCl3, hydrogen, doping with B2H6 or PH3 as an example Doping gas, in order to generate silicon atoms through the reaction of silicon source gas and hydrogen gas and deposit on the silicon wafer W to grow the epitaxial layer on the silicon wafer W, and at the same time dope the epitaxial layer with the dopant gas to obtain the required resistivity Exhaust port 50, the exhaust port 50 is used to discharge the reaction tail gas from the reaction chamber RC; a plurality of heating bulbs 60, the plurality of heating bulbs 60 are arranged on the periphery of the upper quartz bell jar 30A and the lower quartz bell jar 30B and are used for passing through The upper bell jar 30A and the lower bell jar 30B provide a high-temperature environment for vapor phase epitaxy deposition in the reaction chamber RC; and mounting parts 70 for assembling the respective elements of the device 1 .

It should be noted that, in the above-mentioned device 1 commonly used for the epitaxial growth of silicon wafer W, the base support frame 20 includes three support arms 21 distributed at equal intervals along the circumference. The specific top view is shown in FIG. 4 . In the case of the base support frame 20 used for the epitaxial growth of the silicon wafer W, the growth rate of the <110> crystal direction and the <100> crystal direction of the silicon wafer W will be different, so the epitaxial layer grown on the silicon wafer W The thickness will be different, so the flatness of the final epitaxial silicon wafer will be poor.

Based on this, referring to FIG. 5 , an embodiment of the present invention provides a base support frame 200 to replace the base support frame 20 in the device 1 for epitaxial growth of a silicon wafer W shown in FIG. 1 , as shown in FIG. 6 A top view of the base support frame 200 provided by the embodiment of the present invention is shown. Specifically, the base support frame 200 provided by the embodiment of the present invention includes: Four base support arms 201 extending radially outward and axially upward from the longitudinal axis of the base support frame 200, the four base support arms 201 are evenly distributed in the circumferential direction around the longitudinal axis, the four base support arms 201 The base 10 for carrying the silicon wafer W is supported together with the distal end of the base support arm 201; The four concave lenses 202 are respectively connected to the four base support arms 201, and each concave lens 202 extends along the connected support arm of the base 10, and the four concave lenses 202 are arranged so as to correspond to the The four <110> crystal orientations of the silicon wafer W are vertically aligned with the four base support arms 201 respectively, and radiate to the four < The radiant heat at the position of 110>crystal orientation can be refracted and dissipated by the four concave lenses 202 .

In the case where the susceptor support 20 in the apparatus 1 for the epitaxial growth of a silicon wafer W shown in FIG. / 360°, 90°, 180° and 270° positions are provided with corresponding concave lens 202 vertically. Due to the function of the concave lens 202, the heat radiated to the silicon wafer in the W<110> crystal direction will be radiated to the concave lens first. 202, the concave lens 202 will have a certain refraction and divergence effect on radiant heat, so the temperature distribution of the silicon wafer in the W<110> crystal direction can be reduced compared with the use of the base support frame 20, and the base support frame 200 is used instead of the base support After racking 20, the temperature distribution difference from the silicon wafer W<110> crystal orientation to the silicon wafer W<100> crystal orientation is reduced. In this case, the silicon wafer W<110> crystal orientation can be made to the <100> crystal orientation. The growth rate of the epitaxial layer of the silicon wafer W is more uniform, thereby making the thickness of the epitaxial layer of the silicon wafer W more uniform, thereby obtaining an epitaxial silicon wafer with better flatness.

The base support frame 200 is obtained after changing the structure of the original base support frame 20. In order not to introduce new impurities during the epitaxial growth process of the silicon wafer W while changing the structure, preferably, the The base support arm 201 is made of quartz. Correspondingly, the material of the concave lens 202 is also quartz.

During the epitaxial growth process of the silicon wafer W, the pedestal support frame 200 will drive the pedestal 10 to rotate around the X-axis together. Therefore, in order to be able to rotate, the concave lens 202 will not shake relative to the pedestal support arm 201. , in a specific embodiment of the present invention, referring to FIG. 7, each concave lens 202 is provided with a through hole 2021, so that the base support arm 201 can pass through the through hole 2021 to realize the concave lens 202 and the base support The connection of the arm 201. Understandably, in order not to shake between the concave lens 202 and the base support arm 201 during rotation, the size of the through hole 2021 exactly matches the size of the base support arm 201 .

In a specific embodiment of the present invention, optionally, each concave lens 202 is also configured such that radiant heat can be radiated to the periphery of the silicon wafer W through the concave lens 202 . It can be understood that the thickness difference of the epitaxial layer of the silicon wafer W between the crystal orientation <110> and the crystal orientation <100> is more obvious in the region closer to the radial edge of the silicon wafer W, so in order to obtain a more uniform For the thickness of the epitaxial layer, in the embodiment of the present invention, it is more desirable to reduce the temperature of the periphery of the silicon wafer W by adopting the concave lens 202 structure, so as to reduce the above-mentioned difference in the thickness of the epitaxial layer.

Understandably, referring to FIG. 8 , the concave lens 202 includes a concave surface 2023 and a convex surface 2022 , the concave surface 2023 is disposed away from the silicon wafer W, and the convex surface 2022 is disposed toward the silicon wafer W, so as to realize the refraction and divergence effect on radiant heat. As shown in Figure 8, when the heat radiation generated by the heating bulb 60 enters the reaction chamber RC, the radiant heat will first irradiate to the silicon wafer W<110> crystal orientation 0°/360°, 90°, 180° and On the concave surface 2023 of the concave lens 202 directly below 270°, according to the refraction principle of the lens, the radiant heat irradiated on the concave lens 202 is firstly refracted by the concave surface 2023 and then irradiated on the convex surface 2022, and then incident on the convex surface 2022 after being refracted and diverged. On the silicon wafer W, that is to say, the concave lens 202 plays a role of refraction and divergence in the transfer process of radiant heat. In this case, compared with the original base support frame 20, the replaced base support frame 200 The radiant heat irradiated to the W<110> crystal orientation of the silicon wafer is reduced, which means that the temperature rise of the silicon wafer part at the W<110> crystal orientation position of the silicon wafer will slow down, so the epitaxy of the silicon wafer part at the crystal orientation position The layer growth rate will also be reduced; on the other hand, the part of the silicon wafer at the crystal orientation position of the silicon wafer W<100> will irradiate the <100> crystal due to the part of the radiation heat refracted and diverged by the concave lens 202 in addition to receiving the previous radiant heat. Therefore, the epitaxial layer growth rate of the silicon wafer part at the crystal orientation position will be accelerated, so the growth rate of the epitaxial layer from the silicon wafer W<110> crystal orientation to the <100> crystal orientation silicon wafer W will be The epitaxial silicon wafer of a uniform and flat silicon wafer W can also be guaranteed to be obtained gradually.

Based on the size of the base 10 in the device 1 shown in FIG. 3, the size of the reaction chamber RC and the diameter of the silicon wafer W, referring to FIG. 9, in a specific embodiment of the present invention, preferably, each concave lens 202 The distance D1 between the radially outer edge OE and the longitudinal axis may be equal to the radius of the silicon wafer W, corresponding to a diameter of the silicon wafer W of 300 mm, and the extension length D2 of each concave lens 202 in the radial direction may be 3 mm. , the extension angle of the radially outer edge OE of each concave lens 202 in the circumferential direction may be 15°<α<30°.

Referring to FIG. 10 , an embodiment of the present invention also provides a device 2 for epitaxial growth of a silicon wafer W. The device 2 replaces the pedestal support shown in FIG. 3 with the pedestal support frame 200 provided by the embodiment Obtained after rack 20. Specifically, the device 2 may include: a disk-shaped base 10, the base 10 is used to carry the silicon wafer W; the base support frame 200 provided by the embodiment of the present invention; an upper bell jar 30A and a lower bell jar 30B, The upper bell jar 30A and the lower bell jar 30B together enclose the reaction chamber RC accommodating the base 10, wherein the base 10 separates the reaction chamber RC into an upper reaction chamber RC1 and a lower reaction chamber RC2 , the silicon wafer W is placed in the upper reaction chamber RC1; a plurality of heating bulbs 60, the plurality of heating bulbs 60 are arranged on the periphery of the upper quartz bell jar 30A and the lower quartz bell jar 30B and are used to penetrate the upper bell jar 30A and the lower bell jar. The cover 30B provides a high temperature environment for vapor phase epitaxial deposition in the reaction chamber; the gas inlet 40 is used to sequentially deliver cleaning gas and silicon source gas to the reaction chamber RC; the exhaust port 50 , the exhaust port 50 is used to discharge the respective reaction tail gases of the cleaning gas and the silicon source gas out of the reaction chamber RC. In addition, the same as the related device 1 for the epitaxial growth of the silicon wafer W, the device 2 may also include a mounting component 70 and so on, which will not be repeated here.

Referring to FIG. 11 , an embodiment of the present invention also provides a method for epitaxial growth of a silicon wafer W, which is applied to the device 2 provided by the embodiment of the present invention, and the method may include: S1101. Carrying the silicon wafer in the base so that the four <110> crystal directions of the silicon wafer are respectively vertically aligned with the four base support arms; S1102. Turn on the plurality of heating bulbs to increase the temperature of the reaction chamber to 1100° C. to 1150° C., and deliver silicon source gas into the upper reaction chamber through the gas inlet to grow an epitaxial layer on the silicon wafer. ; S1103. The silicon source gas passes through the front side of the silicon wafer from the upper reaction chamber, diffuses to the back side of the silicon wafer, and is discharged into the lower reaction chamber from the gap of the reaction chamber, so that The thickness of the epitaxial layer grown on it is uniform; S1104. Exhaust the reaction tail gas including the silicon source gas discharged into the lower reaction chamber from the reaction chamber through the exhaust port.

It should be noted that: the technical solutions described in the embodiments of the present invention can be combined arbitrarily if there is no conflict.

The above are only preferred embodiments of the present invention, and are not used to limit the implementation scope of the present invention. If the present invention is modified or equivalently replaced without departing from the spirit and scope of the present invention, it shall be covered by the protection of the patent scope of the present invention. in the range.

W100: Silicon Wafer 1: device 2: Device 10: Base 10A: Adjacent parts 20: Base support frame 30A: Upper quartz bell case 30B: Lower quartz bell jar 40: air inlet 50: Exhaust port 60:Heating bulb 70:Installing parts 200: base support frame 201: Base support arm 202: concave lens 2021: Through-hole 2022: Convex 2023: Concave D1: distance D2: Extended length G: Gap W: Wafer X: central axis RC: reaction chamber RC1: upper reaction chamber RC2: Lower Reaction Chamber OE: radial outer edge S1101-S1104: Steps

FIG. 1 is a schematic diagram of the <110> crystal orientation and the <100> crystal orientation of a silicon wafer with a (100) crystal plane provided by an embodiment of the present invention; FIG. 2 is the ESFQR result of the silicon wafer shown in FIG. 1 in the case of using a conventional susceptor for epitaxial growth of the silicon wafer provided by the embodiment of the present invention; 3 is a schematic diagram of a related device for epitaxial growth of a silicon wafer provided by an embodiment of the present invention; 4 is a schematic structural diagram of a base support frame in a related device for epitaxial growth of silicon wafers provided by an embodiment of the present invention; 5 is a schematic structural view of a base support frame in a device for epitaxial growth of a silicon wafer provided by an embodiment of the present invention; 6 is a schematic diagram of a top view of the base support frame in the device for epitaxial growth of silicon wafers provided by the embodiment of the present invention; Fig. 7 is a schematic diagram of the assembly and connection of the base support frame and the concave lens provided by the embodiment of the present invention; Fig. 8 is a schematic diagram of the refraction and divergence effect of the concave lens on the radiant heat provided by the embodiment of the present invention; Fig. 9 is a schematic diagram of the size parameters of the concave lens provided by the embodiment of the present invention; FIG. 10 is a schematic diagram of a device for epitaxial growth of a silicon wafer provided by an embodiment of the present invention; FIG. 11 is a schematic diagram of the flow of a method for epitaxial growth of a silicon wafer provided by an embodiment of the present invention.

10: Base

200: base support frame

201: Base support arm

202: concave lens

W: Wafer

Claims (10)

A pedestal support frame for epitaxial growth of silicon wafers, the pedestal support frame includes: Four base support arms extending radially outward and axially upward from the longitudinal axis of the base support frame, the four base support arms are evenly distributed in the circumferential direction around the longitudinal axis, the four base support arms the distal ends of the arms together support a base for carrying the wafer; The four concave lenses are respectively connected to the four base support arms, each concave lens extends along the connected base support arm, and the four concave lenses are arranged so as to correspond to the silicon chip carried in the base. The four <110> crystal directions are vertically aligned with the four pedestal support arms, and the radiant heat radiated to the positions of the four <110> crystal directions of the silicon wafer through the four concave lenses in the vertical direction can be is refracted and diverged by the four concave lenses. The pedestal support frame for epitaxial growth of silicon wafers as claimed in claim 1, wherein the material of the pedestal support arm is quartz. The pedestal support frame for epitaxial growth of silicon wafers as claimed in claim 1, wherein the material of the concave lens is quartz. The pedestal support frame for epitaxial growth of silicon wafers as described in claim 3, wherein a through hole is provided on the concave lens, so that the pedestal support arm can pass through the through hole to realize the connection between the concave lens and the substrate Seat support arm connection. The susceptor support frame for the epitaxial growth of a silicon wafer as claimed in claim 4, wherein each concave lens is further arranged so that radiant heat can be radiated to the periphery of the silicon wafer through the concave lens. The base support for epitaxial growth of a silicon wafer as claimed in claim 5, wherein the concave lens includes a concave surface and a convex surface, the concave surface is disposed away from the silicon wafer, and the convex surface is disposed facing the silicon wafer. The pedestal support frame for the epitaxial growth of silicon wafers as described in Claim 6, wherein, the radiant heat irradiated to the concave lens is firstly refracted by the concave surface, then irradiated to the convex surface, and then incident to the convex surface after being refracted and diverged by the convex surface on the silicon chip. The base support frame for epitaxial growth of silicon wafer as described in claim 5, wherein the distance between the radially outer edge of each concave lens and the longitudinal axis is equal to the radius of the silicon wafer, corresponding to the The diameter of the sheet is 300 mm, the extension length of each concave lens in the radial direction is 3 mm and the extension angle of the radially outer edge of each concave lens in the circumferential direction is 15°<α<30°. A device for epitaxial growth of a silicon wafer, the device comprising: a disc-shaped base for carrying the silicon wafer; The base support frame for the epitaxial growth of a silicon wafer according to any one of claims 1 to 8; an upper bell and a lower bell, the upper bell and the lower bell together enclosing a reaction chamber housing the base, wherein the base separates the reaction chamber into an upper reaction chamber and a lower reaction chamber chamber, the silicon wafer is placed in the upper reaction chamber; a plurality of heating bulbs arranged on the periphery of the upper quartz bell jar and the lower quartz bell jar and used to provide a high temperature environment for vapor phase epitaxy deposition in the reaction chamber through the upper bell jar and the lower bell jar; an air inlet, the air inlet is used to sequentially deliver cleaning gas and silicon source gas into the reaction chamber; an exhaust port, the exhaust port is used to discharge the respective reaction tail gases of the cleaning gas and the silicon source gas out of the reaction chamber. A method for epitaxial growth of silicon wafers, the method is applied to the device for epitaxial growth of silicon wafers according to Claim 9, the method comprising: supporting the silicon wafer in the susceptor so that the four <110> crystal orientations of the silicon wafer are respectively vertically aligned with the four susceptor support arms; Turning on the plurality of heating bulbs to increase the temperature of the reaction chamber to 1100° C. to 1150° C., and delivering silicon source gas into the upper reaction chamber through the gas inlet to grow an epitaxial layer on the silicon wafer; The silicon source gas passes through the front side of the silicon wafer from the upper reaction chamber, and diffuses to the back side of the silicon wafer and is exhausted from the gap of the reaction chamber into the lower reaction chamber, so that the silicon source gas grows on the silicon wafer. The thickness of the epitaxial layer is uniform; The reaction tail gas including the silicon source gas discharged into the lower reaction chamber is discharged from the reaction chamber through the exhaust port.

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