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Adjustment method of SiC (silicon carbide) single crystal flatness by wet etching

A silicon carbide single crystal and adjustment method technology, applied in chemical instruments and methods, single crystal growth, single crystal growth, etc., can solve problems such as surplus, low-energy surface cannot be exposed smoothly, wafer quality decline, etc.

Active Publication Date: 2014-05-21
BEIJING TIANKE HEDA SEMICON CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] 2) The surface of the wafer is prone to scratches; this is due to the excess carbon remaining during the corrosion process of the wafer, resulting in the low-energy surface not being exposed smoothly, and the energy-concentrated area (high-energy area) is easily eroded
[0007] 3) The back of the chip is easy to turn black, resulting in a decrease in the quality of the chip

Method used

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  • Adjustment method of SiC (silicon carbide) single crystal flatness by wet etching
  • Adjustment method of SiC (silicon carbide) single crystal flatness by wet etching
  • Adjustment method of SiC (silicon carbide) single crystal flatness by wet etching

Examples

Experimental program
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Effect test

Embodiment 1

[0034] Step 1: Take a 6H nitrogen-doped conductive SiC wafer after chemical mechanical polishing (CMP) for standard cleaning, and measure its surface Bow and Warp as: -27.520 microns and 33.456 microns respectively; its surface morphology is as follows: figure 1 As shown, the RMS is 0.155 microns, and it is stored in a vacuum environment.

[0035] Step 2: Take the cleaned wafer, put it into a preheating furnace to preheat to 350°C, keep the temperature for 10 minutes, and set it aside.

[0036]Step 3: Add 1 kg of KOH+NaOH mixture into an aluminum oxide crucible in a ratio of 1:1, raise the temperature to 310°C, wait for half an hour, and then add 100 grams of potassium carbonate as an additive until the entire crucible is melted. Clear, let stand for 20 minutes, blow into oxygen, the flow rate of oxygen blowing is controlled at 200 standard milliliters per minute.

[0037] Step 4: Take the preheated wafer, put it in the molten solution, blow oxygen for 10 seconds, take out th...

Embodiment 2

[0042] Step 1: Take a 2-inch 6H vanadium-doped semi-insulating SiC (0001) silicon surface polished wafer after CMP for standard cleaning, and measure the surface Bow and Warp to be -22.777 microns and 28.490 microns respectively; the surface morphology is as follows Figure 4 As shown, the RMS is 0.130 microns, and it is stored in a vacuum environment.

[0043] Step 2: Take the cleaned wafer, put it into a preheating furnace to preheat to 500°C, keep the temperature for 10 minutes, and set it aside.

[0044] Step 3: Add 1 kg of KOH+NaOH mixture into an aluminum oxide crucible at a ratio of 2:1, heat up to 350°C, wait for 40 minutes, and then add 70 grams of potassium carbonate as an additive until the entire crucible is melted. Clear, let stand for 20 minutes, blow into oxygen, the flow of oxygen blowing is controlled at 300 standard milliliters per minute.

[0045] Step 4: Take the preheated wafer, put it in the molten solution, blow oxygen for 15 seconds, take out the sampl...

Embodiment 3

[0050] Step 1: Take a 3-inch 4H nitrogen-doped conductive SiC (0001) silicon surface polished wafer after CMP for standard cleaning, and measure its surface Bow and Warp to be -44.259 microns and 61.925 microns respectively; its surface morphology is as follows Figure 7 As shown, the RMS is 0.223 microns, and it is stored in a vacuum environment.

[0051] Step 2: Take the cleaned wafer, put it into a preheating furnace and preheat it to 500° C. for 10 minutes, and set it aside.

[0052] Step 3: Add 2 kg of KOH+NaOH mixture into an aluminum oxide crucible at a ratio of 3:1, raise the temperature to 400°C, wait for 60 minutes, and then add 300 grams of potassium carbonate as an auxiliary agent until the entire crucible is filled. Remove clear, leave standstill for 30 minutes, blow in oxygen, and the flow rate of oxygen blowing is controlled at 300 standard milliliters per minute.

[0053] Step 4: Take the preheated wafer, put it in the molten solution, blow oxygen for 20 secon...

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Abstract

The invention provides a method for improving silicon carbide single chip flatness and crystal surfaces by using wet etching. By cleaning, preheating and oxygen-blowing etching silicon carbide single crystal and the like, the method removes dot, line and surface defects on the surfaces of the silicon carbide single crystal and furthest eliminates defects, stress and damaged layers on the surfaces of wafers to a maximum extent, so that the flatness of the silicon carbide wafers can be adjusted to the following parameters: Warp is less than 15mum, absolute Bow is less than 15mum and, and finally the single crystal silicon carbide wafers with high qualities are obtained.

Description

technical field [0001] The invention relates to a method for adjusting the surface and volume parameters of a silicon carbide single crystal, in particular to a method for adjusting the flatness and surface of a silicon carbide single crystal wafer. Background technique [0002] As a wide bandgap semiconductor, single crystal silicon carbide has the characteristics of high thermal conductivity and high saturation electron drift rate. With the increasing needs of high-speed and high-frequency radio technology, wide-bandgap semiconductors have attracted more and more attention. This semiconductor device can meet many advantages that ordinary silicon-based semiconductors cannot meet, such as being able to operate at higher power levels and more Work under high temperature and more severe environment. In fact, metal-semiconductor field-effect transistors and metal-oxide-semiconductor field-effect transistors manufactured on this basis have been realized. Therefore, it is more ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L21/302H01L21/306C30B33/10C30B29/36
Inventor 陈小龙黄青松王波王锡铭李龙远郑红军郭钰
Owner BEIJING TIANKE HEDA SEMICON CO LTD