The present application relates to the technical field of process apparatus, particularly to a wafer susceptor and a chemical vapor deposition apparatus.
At present, a metal-organic chemical vapor deposition (MOCVD) technique is usually used in a fabrication process of a wafer. A graphite disc is disposed in an MOCVD apparatus, several grooves are disposed on the upper surface of a graphite disc, and a piece of wafer is placed in a corresponding groove, a chemical reaction is carried out between the upper surface of the wafer and reaction gas from a spray-head by means of a heating unit of the MOCVD apparatus, thereby a corresponding epitaxial material layer is deposited on the upper surface of the wafer. There are stresses inside the wafer, such that the wafer is warped. Especially during the growth of the aluminum nitride, the periphery of the wafer is warped upward, which leads to the uneven heating of the wafer, and the temperature of the central area is higher than that of the periphery, which leads to the uneven wavelength of the prepared wafer, thereby reducing the yield.
In view of above problems, embodiments of the present application provide a wafer susceptor and a chemical vapor deposition apparatus, used for solving the problem of a decrease in yield due to inconsistent density of deposited epitaxial material caused by uneven heating during wafer manufacturing process.
An embodiment of the present application provides a wafer susceptor and a chemical vapor deposition apparatus including: at least one wafer carrying groove; and two convex structures respectively disposed at the bottom of the wafer carrying groove.
In an embodiment, the wafer carrying groove is circular in shape, and where the two convex structures are respectively disposed on two sides of the circle center of the wafer carrying groove.
In an embodiment, where there is a certain preset distance between the two convex structures.
In an embodiment, where two convex structures are respectively disposed at a position near to a quarter of the periphery of the bottom of the wafer carrying groove.
In an embodiment, where the number of the wafer carrying grooves is one of the following: 3, 6, 14 or 32.
In an embodiment, where the wafer susceptor is a graphite disc.
An epitaxial layer is formed on the wafer when the wafer is placed in the wafer carrying groove, the center area of the wafer is concaved towards the direction of the wafer carrying groove, and the periphery of the wafer is warped towards the direction away from the wafer carrying groove. With the wafer susceptor provided by embodiments of the present application, convex structures are disposed at the bottom of the wafer carrying groove, such that the wafer is more uniformly heated, and the wavelength of the epitaxial layer formed on the wafer is also more uniform.
The technical solutions in the embodiments of the present application will be clearly and completely described below which combine with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some of the embodiments of the present application rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present application.
As shown in
In the embodiment shown in
In an embodiment of the present application, the wafer carrying groove 2 may include a step structure 21, and the step structure 21 is disposed in the wafer carrying groove 2 and is fit to the inner wall of the wafer carrying groove 2. The height of the step structure 21 is less than the height of the wafer carrying groove 2. The step structure 21 is used to support the wafer 3, so that there is a certain space between the wafer 3 and the bottom of the wafer carrying groove 2 to prevent the contact between the wafer 3 and the convex structures 22, so as to avoid certain damage to the wafer 3 due to the high temperature of the contact surface.
It should be understood that the step structure 21 may be a ring structure surrounding the bottom of the wafer carrying groove 2, or the step structure 21 may be several steps distributed at the bottom of the wafer carrying groove 2 according to a preset distance, and the specific shape of the step structure 21 is not limited in the embodiment of the present application.
In an embodiment of the present application, the maximum height of the convex structure 22 is less than the depth of the groove, and the maximum height of the convex structure 22 is also less than the height of the step structure 21 to prevent the convex structure 22 from contacting the wafer 3.
In the embodiment shown in
It should be understood that the wafer susceptor 1 may be a graphite disc, or the wafer susceptor 1 may also be made of other materials, and the specific material of the wafer susceptor 1 is not limited in the embodiment of the present application.
During the preparation process of the wafer 3, the central area of the wafer 3 will be concaved and the periphery of the wafer 3 will be warped. The convex structures 22 are disposed on two sides of the center of a circle, such that the heated temperature on the surface of the entire wafer 3 is more uniform, and thereby the wavelength of the epitaxial layer formed on the wafer 3 is also more uniform.
In the above embodiments, the two convex structures 22 are disposed continuously; the distance between the two convex structures 22, however, is not particularly limited in the present application.
The convex structure 22 have a variety of shapes, it should be understood that, it may have either a circular arc cross-section as shown in
Those described above are merely preferred embodiments of the present application, and by no way to limit the present application thereto. Any modifications, equivalent substitution, etc. within the spirit and principle of the present application are covered by the protection scope of the present application.
This application is a continuation of International Application No. PCT/CN2019/127086, filed on Dec. 20, 2019, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2019/127086 | Dec 2019 | US |
Child | 17478638 | US |