CN110793662A

CN110793662A - Method for calibrating temperature field of large-size silicon carbide high-temperature reaction device

Info

Publication number: CN110793662A
Application number: CN201911052030.6A
Authority: CN
Inventors: 张新河; 陈施施; 温正欣; 杨安丽; 叶怀宇; 张国旗
Original assignee: Shenzhen Third Generation Semiconductor Research Institute
Current assignee: Southwest University of Science and Technology
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-02-14
Anticipated expiration: 2039-10-31
Also published as: CN110793662B

Abstract

The invention discloses a method for calibrating a temperature field of a large-size silicon carbide high-temperature reaction device. The method at least comprises the following steps: the silicon carbide substrate is used for calibrating the high-temperature reaction chamber; protecting the back surface of the silicon carbide substrate by using a blue film, and spraying polishing solution containing nano silicon dioxide with certain concentration on the surface; standing for several minutes, cleaning the substrate material, and washing away the polishing solution on the surface of the substrate material, wherein the nano silicon dioxide in the polishing solution is crystallized and uniformly distributed on the silicon carbide substrate; removing the blue film on the back of the substrate, putting the silicon carbide substrate into a silicon carbide high-temperature reaction device to be calibrated, and heating to a specified temperature; cooling and taking out the substrate; observing the distribution condition of the nano silicon dioxide crystals on the surface of the silicon carbide substrate to obtain a temperature field of the silicon carbide high-temperature reaction device; after the detection is finished, the silicon carbide substrate is cleaned by hydrofluoric acid and can be recycled. The method is simple to operate, has high repetition rate, can effectively represent the temperature field distribution of the large-size silicon carbide high-temperature reaction device, and is beneficial to obtaining the stable temperature field of silicon carbide reaction equipment and improving the uniformity of a silicon carbide epitaxial layer.

Description

Method for calibrating temperature field of large-size silicon carbide high-temperature reaction device

Technical Field

The invention belongs to the technical field of semiconductors, and particularly relates to a temperature field calibration method for a large-size silicon carbide high-temperature reaction device.

Background

The third generation semiconductor silicon carbide material has the advantages of high thermal conductivity, high breakdown field strength, high saturated electron drift rate and the like, can meet the new requirements of modern electronic technology on severe conditions such as high temperature, high power, high voltage, high frequency, radiation resistance and the like, and is also the strategic direction of the semiconductor technology in China in the future. With the continuous popularization and development of the third-generation semiconductor material, the semiconductor material plays a key role in the industries of power electronics, aerospace, new energy, smart power grids, electric vehicles and the like.

In order to promote the industrial development of SiC power devices, the production cost of the power devices must be reduced as much as possible, 6-inch silicon carbide has become the mainstream of the market at present, 8-inch silicon carbide substrates have been released in 2015, and rapid response of various substrate companies is obtained, and the commercialization process is promoted rapidly. 8-inch device fabrication equipment is also mature and it is expected that oversized silicon carbide will rapidly reduce silicon carbide device fabrication costs, driving the benign growth of commercial applications for silicon carbide devices.

However, no oversized silicon carbide epitaxial equipment exists at present, and one important reason is that the uniformity of oversized silicon carbide epitaxial wafers is extremely difficult to control, and a large-sized silicon carbide high-temperature reaction device can cause temperature field changes due to stress accumulation and deformation of reaction coils caused by equipment use, accessory aging and frequent temperature rise and fall, so that the manufacturing uncertainty of oversized silicon carbide devices is increased. Therefore, the rapid determination of the temperature field change of a large-size silicon carbide high-temperature reaction device becomes a conventional requirement in daily production.

The invention provides a temperature field calibration method for a large-size silicon carbide high-temperature reaction device, which can effectively judge the temperature field change of equipment by rapidly melting silicon dioxide crystals on the surface of a silicon carbide substrate at high temperature and taking away the silicon dioxide crystals by hydrogen, further adopts corresponding equipment process improvement, finally stably obtains a high-uniformity and ultra-large-size silicon carbide epitaxial material, and meets the requirements of customers on the uniformity of the epitaxial layer thickness and the epitaxial layer doping concentration of a silicon carbide epitaxial wafer.

Disclosure of Invention

The invention aims to provide a temperature field calibration method for a large-size silicon carbide high-temperature reaction device, which can effectively judge the temperature field change of equipment and carry out corresponding equipment process improvement by rapidly melting silicon dioxide crystals on the surface of a silicon carbide substrate at high temperature and taking away the silicon dioxide crystals by hydrogen, finally stably obtain a high-uniformity and ultra-large-size silicon carbide epitaxial material, and meet the requirements of customers on the uniformity of the epitaxial layer thickness and the doping concentration of the epitaxial layer of a silicon carbide epitaxial wafer.

In order to achieve the above purpose, the present invention provides a method for calibrating a temperature field of a large-sized silicon carbide high-temperature reaction apparatus. Characterized in that the method at least comprises: a substrate silicon carbide substrate A used for calibrating the high-temperature reaction chamber; protecting the back surface of the silicon carbide substrate by using a blue film B, and spraying polishing solution C containing nano silicon dioxide with certain concentration on the silicon carbide substrate A; standing the silicon carbide substrate material A sprayed with the polishing solution C containing nano silicon dioxide with a certain concentration for several minutes, cleaning the silicon carbide substrate material A, and washing away the residual polishing solution on the surface of the silicon carbide substrate material A, wherein the nano silicon dioxide in the polishing solution is crystallized D on the silicon carbide substrate A and is uniformly distributed; uncovering the blue film for protecting the back surface of the silicon carbide substrate A, and putting the silicon carbide substrate A with the uniformly distributed nano silicon dioxide crystals into a silicon carbide high-temperature reaction device to be calibrated to heat to a specified temperature; cooling and taking out the silicon carbide substrate A; observing the distribution condition of the nano silicon dioxide crystals D on the surface of the silicon carbide substrate A under a microscope, and obtaining the temperature field of the silicon carbide high-temperature reaction device according to the distribution form; and after the detection is finished, cleaning the silicon carbide substrate A by hydrofluoric acid, and removing the residual nano silicon dioxide crystal on the surface for recycling.

The observation target is silicon dioxide crystal formed by standing the polishing solution, and the diameter of the observation target is 80-200 nm.

The step of placing the substrate with the nano silicon dioxide crystals uniformly distributed on the surface into a silicon carbide high-temperature reaction device to be calibrated further comprises the following steps: and introducing hydrogen while putting the silicon carbide high-temperature reaction device to be calibrated.

The distribution situation comprises: according to the distribution pattern formed by melting silicon dioxide crystals at a specified temperature and carrying the silicon dioxide crystals away by hydrogen.

The invention observes that the silicon dioxide particles crystallized on the surface of the silicon carbide substrate are heated and melted in a large-size silicon carbide high-temperature reaction device and are H-melted₂The temperature field of the large-size silicon carbide high-temperature reaction device can be described by the distribution of the carried-away graphs, and the temperature field calibration is carried out according to the distribution condition of the temperature field. Meanwhile, the used silicon carbide substrate can be continuously and repeatedly used after being cleaned by hydrofluoric acid, and the testing method is simple and rapid.

Drawings

FIG. 1 is a flow chart illustrating a method for temperature field calibration for a large-scale silicon carbide high-temperature reaction apparatus according to the present invention.

FIG. 2 is a schematic diagram of example process step S3.

FIG. 3 is a schematic diagram of example process step S5.

FIG. 4 is a schematic diagram of example process step S8.

FIG. 5 shows the distribution of nano-silica crystals on the surface of a silicon carbide substrate.

Fig. 6 is a silicon dioxide crystal distribution of the silicon carbide substrate surface distribution after heating.

FIG. 7 shows a silicon carbide substrate A with uniformly distributed nano-silica crystals in the example, which is placed in a silicon carbide high-temperature reaction device to be calibrated and heated to a specified temperature; cooling and taking out the silicon carbide substrate A; the distribution of the nano-silica crystals D on the surface of the silicon carbide substrate a was observed under a microscope. Wherein the temperature field distribution condition of the large-size silicon carbide high-temperature reaction device can be obtained according to the distribution condition of the residual nano silicon dioxide crystals D.

Detailed description of the invention

The embodiments herein and the various features and relevant details of the embodiments described below in connection with the specific examples are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not obscure the embodiments herein with unnecessary description. In performing the operation, a conventional process well known in the semiconductor process may be used. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples herein should not be construed as limiting the scope of the embodiments herein.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than the number, shape and size of the components in actual implementation, and the type, number and ratio of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.

The invention provides a method for calibrating a temperature field of a large-size silicon carbide high-temperature reaction device, which comprises the following specific steps of:

s1) was tested on a conventional commercial 6-inch silicon carbide substrate subjected to cleaning.

S2) using the blue film B to protect the 6-inch silicon carbide from being stained by the polishing liquid on the back surface.

S3) spraying a silicon carbide substrate material A containing polishing solution C of nano silicon dioxide with a certain concentration to 6 inches of silicon carbide with complete blue film protection on the back surface,

s4), standing for several minutes, then washing with pure water, and washing away the residual polishing solution on the surface of the silicon carbide substrate material;

s5) uncovering the protective blue film on the back of the silicon carbide substrate

S6) putting the silicon carbide substrate A with the uniformly distributed nano silicon dioxide crystals into a silicon carbide high-temperature reaction device to be calibrated, and simultaneously introducing carrier gas H according to the normal growth process₂Heating the mixture to a specified temperature,

s7) cooling to room temperature, taking out the silicon carbide substrate

S8) observing the distribution condition of the nano silicon dioxide crystals on the surface of the silicon carbide substrate A under a microscope, and obtaining the temperature field of the silicon carbide high-temperature reaction device according to the distribution form;

s9), cleaning the silicon carbide substrate A with hydrofluoric acid after detection is finished, and removing the nano silicon dioxide crystal remained on the surface for recycling.

The foregoing is illustrative of the preferred embodiments of the present invention and is not to be construed as limiting thereof in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. It will be apparent to those skilled in the art that various modifications and variations can be made in the above methods and techniques without departing from the scope of the invention, and it is intended to cover all such modifications, variations and changes as fall within the true spirit and scope of the invention.

Claims

1. A method for calibrating a temperature field of a large-size silicon carbide high-temperature reaction device is characterized by comprising the following steps:

a substrate for calibrating a high temperature reaction apparatus,

a blue film is used to cover the back side of the substrate,

spraying polishing solution containing nano silicon dioxide on the surface of the substrate,

standing the substrate for several minutes, cleaning the substrate, washing away polishing solution on the surface to obtain the substrate with nano silicon dioxide crystals uniformly distributed on the surface,

removing the blue film covering the back surface of the substrate,

putting the substrate with the nano silicon dioxide crystals uniformly distributed on the surface into a silicon carbide high-temperature reaction device to be calibrated and heating to a specified temperature,

cooling and taking out the substrate,

observing the distribution of the nano silicon dioxide crystals on the surface of the substrate under a microscope,

obtaining the temperature field of the silicon carbide high-temperature reaction device according to the distribution form of the nano silicon dioxide crystals,

and calibrating according to the temperature field condition of the silicon carbide high-temperature reaction device.

2. The method for temperature field calibration for large-scale silicon carbide high-temperature reaction devices according to claim 1, further comprising: and after the detection is finished, cleaning the substrate by using hydrofluoric acid, and removing the residual nano silicon dioxide crystal on the surface, wherein the substrate can be repeatedly used.

3. The method for temperature field calibration for large-scale silicon carbide high-temperature reaction devices according to claim 1, wherein the substrate is a silicon carbide substrate.

4. The method for temperature field calibration for large-sized silicon carbide high-temperature reaction devices according to claim 1, wherein the nano-silica is crystallized and has a diameter of 80-200 nm.

5. The method for temperature field calibration for large-sized silicon carbide high-temperature reaction device according to claim 1, wherein the placing the substrate with the nano-silica crystals uniformly distributed on the surface into the silicon carbide high-temperature reaction device to be calibrated further comprises: and introducing hydrogen while putting the silicon carbide high-temperature reaction device to be calibrated.

6. The method for temperature field calibration for large-size silicon carbide high-temperature reaction devices according to claim 1, wherein the distribution comprises: according to the distribution pattern formed by melting silicon dioxide crystals at a specified temperature and carrying the silicon dioxide crystals away by hydrogen.