CN214244604U

CN214244604U - Carrier disc and carrier for growth of silicon carbide epitaxial wafer

Info

Publication number: CN214244604U
Application number: CN202023178140.8U
Authority: CN
Inventors: 毛张文; 林志东; 郑元宇; 张富钦
Original assignee: Xiamen Sanan Integrated Circuit Co Ltd
Current assignee: Hunan Sanan Semiconductor Co Ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-09-21
Anticipated expiration: 2030-12-25

Abstract

The utility model discloses a carrying disc for the growth of a silicon carbide epitaxial wafer, which comprises an annular body and an extension part for placing a silicon carbide substrate, wherein the extension part extends along the circle center direction of the annular body and protrudes out of the annular body, and the annular body is provided with a plurality of extension parts; the extension part is in a strip shape and/or a block shape. The utility model also discloses a microscope carrier that adopts this year dish for carborundum epitaxial wafer grows. The utility model discloses can improve the homogeneity of carborundum epitaxial wafer growth temperature to improve its doping concentration homogeneity.

Description

Carrier disc and carrier for growth of silicon carbide epitaxial wafer

Technical Field

The utility model relates to a semiconductor production tool's technical field refers in particular to a year dish and microscope carrier that is used for carborundum epitaxial wafer to grow.

Background

Compared with silicon (Si), the silicon carbide (SiC) has the advantages of high forbidden band width, high thermal conductivity, high critical breakdown electric field and other beneficial physical properties, can be widely applied to power electronic devices with high temperature, high voltage, high power and the like, and has extremely high application value. The SiC devices on the market today are fabricated by homoepitaxial SiC epitaxial SiC layers on SiC substrates to form SiC epitaxial wafers, and then fabricating the devices on the SiC epitaxial wafers. Compared with the method of directly manufacturing devices on the SiC substrate, the epitaxial wafer with various specifications can be grown through the growth of the homogeneous epitaxial layer so as to meet the design requirements of the devices.

The SiC homoepitaxial growth is usually obtained by a Chemical Vapor Deposition (CVD) method, and the main specification parameters of the homoepitaxial SiC epitaxial wafer are defect density, doping concentration and epitaxial layer thickness. The doping concentration and the epitaxial layer thickness affect the electrical performance of the device, and therefore the inter-wafer uniformity and the intra-wafer uniformity are very important.

As shown in fig. 1, in general, SiC epitaxial wafer growth is performed by placing a SiC substrate in a carrier plate 14 of a stage 1, and heating the SiC substrate to grow a SiC layer with the stage 1 positioned above a heater 2.

During production, the carrier 1 actually used comprises at least the following components: a disc support 11, a base 12, an annular disc 14 and a cover 15, wherein the annular disc 14 mainly comprises graphite or graphite matched with other Si and C compounds in order to ensure temperature transmission as much as possible. The annular carrier disc 14 is mainly used for carrying the SiC substrate 3, a certain gap is formed between the annular carrier disc and the base 12 which is responsible for transmitting the SiC substrate 3, the SiC substrate 3 is prevented from being in direct contact with the base 12, and the damage to the back surface of the SiC substrate 3 is reduced.

Based on the above, the SiC substrate 3 (SiC epitaxial wafer is formed after growing the SiC layer on the SiC substrate 3) will have two temperature regions a and B during the growth. As shown in fig. 2, a region a is a suspended region of the SiC substrate 3 (a position facing the vacancy of the annular carrier plate 14), and a region B is a region where the SiC substrate 3 is in contact with the annular carrier plate 14. Since the thermal conductivity of the edge contact (annular carrier plate 14) and the gas below the center of the SiC substrate 3 is not uniform, temperature inconsistency at the center and edge of the SiC substrate 3 may result, resulting in deterioration of uniformity of concentration of the SiC layer grown on the SiC substrate 3.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a carry dish and microscope carrier for carborundum epitaxial wafer is grown is provided, can improve carborundum epitaxial wafer growth temperature's homogeneity to improve its doping concentration homogeneity.

In order to solve the technical problem, the technical solution of the utility model is that:

a carrier disc for growing a silicon carbide epitaxial wafer comprises an annular body and an extension part for placing a silicon carbide substrate, wherein the extension part extends along the direction of the circle center of the annular body and protrudes out of the annular body, and the annular body is provided with a plurality of extension parts; the extension part is in a strip shape and/or a block shape.

Further, the strip-shaped extending parts are arranged in parallel or in a crossed mode.

Further, at least three block-shaped extending parts are arranged at intervals.

Further, the blocky extending parts are uniformly distributed.

Furthermore, a gasket with patterns is covered on the block-shaped extending part.

Furthermore, the strip-shaped extension part is provided with a contact area and a support area, the cross section of the contact area is triangular, and the cross section of the support area is square.

A carrier for growing silicon carbide epitaxial wafers is provided with a carrier disc, wherein the carrier disc comprises an annular body and an extension part for placing a silicon carbide substrate, the extension part extends along the direction of the circle center of the annular body and protrudes out of the annular body, and the annular body is provided with a plurality of extension parts; the extension part is in a strip shape and/or a block shape.

The utility model discloses a reduce the area of contact of carborundum substrate and year dish to reduce the carborundum substrate in the epitaxial growth in-process marginal temperature and central temperature's difference, guarantee the homogeneity of temperature in the face, improve the SiC layer concentration homogeneity of growing in the face.

Drawings

FIG. 1 is a schematic diagram of a prior art carrier;

FIG. 2 is a top view of a prior art boat;

FIG. 3 is a top view of a first embodiment of the boat of the present invention;

FIG. 4 is a top view of a second embodiment of the boat of the present invention;

FIG. 5 is a top view of a third embodiment of the boat of the present invention;

FIG. 6 is a top view of a fourth embodiment of the boat of the present invention;

fig. 7 is a schematic diagram of a structure of a stage according to the second embodiment;

fig. 8 is a cross-sectional view of the carrier tray with strip-like extensions in contact with the substrate.

Description of the reference symbols

Base 12 of carrier plate support frame 11 of carrier 1

Annular carrier plate 14 cover 15 heater 2 substrate 3

Strip-shaped extension 41 of carrier disk 4 contacts contact area 411 with support area 412

Block extension 42 spacers 421 annular body 43.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be noted that, if the terms "upper", "lower", "inner", "outer" and other orientations or positional relationships are used in the drawings, or the orientations or positional relationships that are usually placed when the product of this application is used, the description is only for convenience, and the present invention is not limited thereto. The technical features mentioned in the embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The utility model discloses a carry dish for carborundum epitaxial wafer is grown, including annular body 43 and the extension of placing carborundum substrate 3, the extension extends along the centre of a circle direction of annular body 3 (the extension is located the inside of annular body 3 promptly) to protruding annular body 43 has a plurality of extensions on the annular body 3, and the extension is strip and/or cubic, has strip extension 41 and/or cubic extension 42 on the annular body 3 promptly.

The extending portions may be all in the shape of a bar, as shown in fig. 3, the number of the bar extending portions 41 is three, and the extending portions are uniformly distributed, as shown in fig. 4, the number of the bar extending portions 41 is two, and the bar extending portions are arranged in parallel, or, as shown in fig. 5, the number of the block extending portions 42 is three, and the bar extending portions are uniformly distributed, or, as shown in fig. 6, one portion is in the shape of a bar, and the other portion is in the shape of a block, two block extending portions 42 and one bar extending portion 41.

The first embodiment is as follows: as shown in fig. 3, for the preferred embodiment of the present invention, the annular body 43 has three strip-shaped extensions 41, two ends of the strip-shaped extensions 41 are located on the annular body 3, and the three strip-shaped extensions 41 are arranged in a crossed manner, that is, the extension lines of the strip-shaped extensions 41 respectively intersect with the extension lines of two adjacent strip-shaped extensions 41, and the intersection points are not in the suspended area of the SiC substrate 3, however, the crossed arrangement may also have other various manners, for example, the strip-shaped extensions 41 respectively intersect with two adjacent strip-shaped extensions 41, and the intersection points are in the suspended area of the SiC substrate 3 to form a grid shape.

The silicon carbide substrate 3 is placed on the three strip-shaped extensions 41, as shown in fig. 8, the strip-shaped extensions 41 have a contact region 411 (i.e., the silicon carbide substrate 3 is connected to the contact region 411) and a support region 412, the cross section of the contact region 411 is triangular, which can further reduce the contact area, and the cross section of the support region 412 is square, which further improves the ability of bearing weight. The contact area between the silicon carbide substrate 3 and the carrying disc 4 is reduced to the contact area between the strip-shaped extension part 41 and the silicon carbide substrate 3, which is far smaller than the contact area in the region B in the prior art.

Example two: as shown in fig. 4, the annular body 43 has two strip-shaped extensions 41, two ends of each strip-shaped extension 41 are located on the annular body 3, the two strip-shaped extensions 41 are arranged in parallel, and the silicon carbide substrate 3 is placed on the two strip-shaped extensions 41, so that the contact area between the silicon carbide substrate 3 and the carrier plate 4 is also significantly reduced.

Example three: as shown in fig. 5, the annular body 43 has three block-shaped extensions 42 spaced apart from each other. The silicon carbide substrate 3 is placed on the three block-shaped extending parts 41, and a stable equilateral triangle can be formed after connecting the positions of two adjacent block-shaped extending parts 42, so that the placing stability of the silicon carbide substrate is improved. The contact area of the silicon carbide substrate 3 and the carrier plate 4 is reduced to the contact area of the block-shaped extension part 42 and the silicon carbide substrate 3, which is far smaller than that in the prior art.

Further, a spacer 421 having a pattern may be covered on the block-shaped extending portion 42 to increase the contact friction force, thereby preventing the silicon carbide substrate 3 from displacement and shaking.

Example four: as shown in fig. 6, the annular body 43 has three extensions, namely a strip-shaped extension 41 and two block-shaped extensions 42, and the silicon carbide substrate 3 is placed on the strip-shaped extension 41 and the block-shaped extensions 42, and similarly, the contact area between the silicon carbide substrate 3 and the boat 4 is also significantly reduced.

As shown in fig. 7, the present invention is applied to the carrier 1, and at least includes the following components: a boat support 11, a base 12, a boat 4, and a cover 15. The base 12 is fixed on the carrying disc support frame 11, the carrying disc 4 is arranged on the carrying disc support frame 11, the covering part 15 covers on the annular body 43 of the carrying disc 4, the silicon carbide substrate 3 is placed on the two strip-shaped extending parts 41 of the carrying disc 4, and the silicon carbide substrate 3 is heated to grow a SiC layer.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that all changes and modifications made according to the claims and the specification of the present invention should fall within the scope covered by the present invention.

Claims

1. A boat for use in the growth of silicon carbide epitaxial wafers, comprising: the silicon carbide substrate extension part extends along the direction of the circle center of the annular body and protrudes out of the annular body, and the annular body is provided with a plurality of extension parts; the extension part is in a strip shape and/or a block shape.

2. A boat for use in the growth of silicon carbide epitaxial wafers in accordance with claim 1, wherein: and the strip-shaped extending parts are arranged in parallel or in a crossed mode.

3. A boat for use in the growth of silicon carbide epitaxial wafers in accordance with claim 1, wherein: at least three block-shaped extensions are provided, spaced apart from each other.

4. A boat for use in the growth of silicon carbide epitaxial wafers in accordance with claim 3, wherein: the blocky extending parts are uniformly distributed.

5. A boat for use in the growth of silicon carbide epitaxial wafers in accordance with claim 1, wherein: the block-shaped extending part is covered with a gasket with patterns.

6. A boat for use in the growth of silicon carbide epitaxial wafers in accordance with claim 1, wherein: the strip-shaped extension part is provided with a contact area and a support area, the cross section of the contact area is triangular, and the cross section of the support area is square.

7. A carrier for the growth of silicon carbide epitaxial wafers, comprising: having a boat as claimed in claim 1.