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

A technology of wet etching and adjustment methods, which is applied in the direction of single crystal growth, single crystal growth, chemical instruments and methods, etc., to achieve the effect of improving wafer flatness and wafer quality

Active Publication Date: 2012-07-11
BEIJING TIANKE HEDA SEMICON CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Wafer quality has b

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
Comparison scheme
Effect test

Example Embodiment

[0033] Embodiment one:

[0034] Step 1: Take a piece of silicon carbide wafer with 6H silicon surface after CMP for standard cleaning, and measure its surface TTV, Bow and Warp as: 8.996 microns, -27.520 microns, 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 and preheat it to 350° C. 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 molten pool, blow oxygen for 10 seconds...

Example Embodiment

[0041] Embodiment two:

[0042] Step 1: Take a vanadium-doped semi-insulating 2-inch 4H-SiC (0001) silicon surface polished wafer after CMP for standard cleaning, and measure its surface TTV, Bow and Warp as: 9.332 microns, -22.777 microns, 28.490 microns ; its surface morphology is as 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 and preheat it to 500° C. 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 molten pool, blow oxygen for 15 seconds, take out ...

Example Embodiment

[0049] Embodiment three:

[0050] Step 1: Take a 3-inch nitrogen-doped 6H-SiC (0001) silicon surface polished wafer after CMP for standard cleaning, and measure its surface TTV, Bow and Warp as: 13.012 microns, -44.259 microns, 61.925 microns; Surface morphology such as 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, heat up to 400°C, wait for 60 minutes, and then add 300 grams of potassium carbonate as an additive until the entire crucible is melted. Clear, let stand for 30 minutes, blow into oxygen, the flow of oxygen blowing is controlled at 300 standard milliliters per minute.

[0053] Step 4: Take the preheated wafer, put it in the molten molten pool, blow oxygen for 20 seconds, take out the samples ran...

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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 surface and flatness 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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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
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