Method of detecting crystallographic defects and method of growing an ingot

Patent metadata

Field	Value
Publication number	US-12398485-B2
Application number	US-202217721949-A
Country	US
Kind code	B2
Filing date	Apr 15, 2022
Priority date	Apr 16, 2021
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

The invention provides a method of detecting crystallographic defects, comprising: sampling wafer of an ingot in complying with a predetermined wafer sampling frequency; identifying crystallographic defects of the wafer to show the crystallographic defects of the wafer; characterizing observation of the crystallographic defects of the wafer and extracting a value characterizing the crystallographic defects; through a result of characterizing the crystallographic defects, obtaining a radial distribution of density of the wafer and categorizing the crystallographic defects; and obtaining an isogram of the crystallographic defects of the wafer to show a crystallographic defect distribution of the whole ingot according to the value characterizing the crystallographic defects and categories of the crystallographic defects. It is no need to break the ingot to obtain the crystallographic defect distribution of the whole ingot, through which the technology for growing the ingot may be effectively adjusted to obtain the ingot with required characteristics of defect.

First claim

What is claimed is:

1. A method of detecting crystallographic defects, comprising:
sampling wafer of an ingot in complying with a predetermined wafer sampling frequency;
identifying crystallographic defects of the wafer to show the crystallographic defects of the wafer;
characterizing observation of the crystallographic defects of the wafer and extracting a value characterizing the crystallographic defects;
through a result of characterizing the crystallographic defects, obtaining a radial distribution of density of the wafer and categorizing the crystallographic defects; and
obtaining an isogram of the crystallographic defects of the wafer to show a crystallographic defect distribution of the whole ingot according to the value characterizing the crystallographic defects and categories of the crystallographic defects,
wherein the step of identifying crystallographic defects of the wafer comprises vapor phase epitaxial (VPE) deposition, gas etching, copper modification and bulk micro-defect (BMD) heat treatment.

2. The method of detecting crystallographic defects according to claim 1 , wherein the categories of the crystallographic defects comprise vacancy defect and self-interstitial defect.

3. The method of detecting crystallographic defects according to claim 1 , wherein the step of characterizing observation of the crystallographic defects of the wafer comprises observing the crystallographic defects of the wafer with one of an optical microscope, light scattering tomography, laser light scattering and minority carrier lifetime.

4. The method of detecting crystallographic defects according to claim 1 , wherein the step of sampling wafer of the ingot is performed along with a longitudinal direction of the ingot.

5. The method of detecting crystallographic defects according to claim 4 , wherein the predetermined wafer sampling frequency is 1/10 millimeter −1 (mm −1 )˜ 1/200 mm −1 .

6. The method of detecting crystallographic defects according to claim 1 , wherein the step of obtaining the isogram of the crystallographic defects of the wafer comprises inputting the value characterizing the crystallographic defects and categories of the crystallographic defects into an analog editor to draw the isogram of the crystallographic defects of the wafer, and the analog editor is one of MATLAB analog editor or Python analog editor.

7. A method of growing an ingot, comprising:
sampling wafer of an ingot in complying with a predetermined wafer sampling frequency;
identifying crystallographic defects of the wafer to show the crystallographic defects of the wafer;
characterizing observation of the crystallographic defects of the wafer and extracting a value characterizing the crystallographic defects;
through a result of characterizing the crystallographic defects, obtaining a radial distribution of density of the wafer and categorizing the crystallographic defects;
obtaining an isogram of the crystallographic defects of the wafer to show a crystallographic defect distribution of the whole ingot according to the value characterizing the crystallographic defects and categories of the crystallographic defects; and
adjusting a technology for growing the ingot according to the crystallographic defect distribution of the whole ingot to obtain the ingot with required characteristics of defect,
wherein the step of identifying crystallographic defects of the wafer comprises vapor phase epitaxial (VPE) deposition, gas etching, copper modification and bulk micro-defect (BMD) heat treatment.

8. The method of growing an ingot according to claim 7 , wherein the step of adjusting the technology for growing the ingot comprises lowering a pulling rate of the ingot or raising a temperature gradient when the crystallographic defects are vacancy defects.

9. The method of growing an ingot according to claim 7 , wherein the step of adjusting the technology for growing the ingot comprises raising a pulling rate of the ingot or lowering a temperature gradient when the crystallographic defects are self-interstitial defects.

Assignees

• Zing Semiconductor Corp
• Shanghai Inst Microsystem & Information Tech Cas

Inventors

• Wei Xing
• Liu Yun
• Wang Xun
• Xue Zhongying

Classifications

• G01N33/0095

  Semiconductive materials · CPC title

• G01N21/9505

  Wafer internal defects, e.g. microcracks · CPC title

• C30B29/06

  Silicon · CPC title

• C30B23/002

  Controlling or regulating · CPC title

• G01N2021/8874

  Taking dimensions of defect into account · CPC title