Method of evaluating silicon wafer and method of manufacturing silicon wafer

• US 8,411,263 B2
• Filed: 04/30/2012
• Issued: 04/02/2013
• Est. Priority Date: 05/20/2011
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Uchino, Shin, Hourai, Masataka, Koike, Yasuo, Ohno, Ryuji
• Primary Examiner(s): Ton, Tri T
• Application Number:
  US13/459,776
• Publication Number:
  US 20120293793A1
• Time in Patent Office: 337 Days
• Field of Search: 3562372-2376, 422/68.1, 422/82.01, 422/82.05, 422/82.07, 422/82.08, 422/82.09, 250/370.01, 436/172
• US Class Current: 356/237.2
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G01N 21/6489 Photoluminescence of semiconductors
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14

Abstract

A method of evaluating a silicon wafer includes obtaining first surface distribution information indicating an surface distribution of photoluminescence intensity on a surface of a silicon wafer; after obtaining the first surface distribution information, subjecting the silicon wafer to a thermal oxidation treatment, and then obtaining second surface distribution information indicating an surface distribution of photoluminescence intensity on the surface of the silicon wafer; obtaining difference information for the first surface distribution information and third surface distribution information, with the third surface distribution information having been obtained by correcting the second surface distribution information with a correction coefficient of less than 1; and based on the difference information obtained, evaluating an evaluation item selected from the group consisting of absence or presence of oxygen precipitates and surface distribution of oxygen precipitates in the silicon wafer being evaluated.

Claims

1. A method of evaluating a silicon wafer, which comprises:

obtaining first surface distribution information indicating an surface distribution of photoluminescence intensity on a surface of a silicon wafer being evaluated;

after obtaining the first surface distribution information, subjecting the silicon wafer being evaluated to a thermal oxidation treatment, and then obtaining second surface distribution information indicating an surface distribution of photoluminescence intensity on the surface of the silicon wafer being evaluated;

obtaining difference information for the first surface distribution information and third surface distribution information, with the third surface distribution information having been obtained by correcting the second surface distribution information with a correction coefficient of less than 1; and

based on the difference information obtained, evaluating an evaluation item selected from the group consisting of absence or presence of oxygen precipitates and surface distribution of oxygen precipitates in the silicon wafer being evaluated.

2. The method of evaluating a silicon wafer according to claim 1, wherein the silicon wafer is a p+ wafer with a resistivity of equal to or lower than 0.1Ω

·

cm or a p/p+ wafer having a p-type epitaxial layer on a p+ substrate with a resistivity of equal to or lower than 0.1Ω

·

cm.

3. The method of evaluating a silicon wafer according to claim 1, wherein the correction coefficient is a value calculated as [(standard photoluminescence intensity in the first surface distribution information)/(standard photoluminescence intensity in the second surface distribution information)].

4. The method of evaluating a silicon wafer according to claim 3, wherein the standard photoluminescence intensity is a maximum photoluminescence intensity.

5. The method of evaluating a silicon wafer according to claim 1, wherein the surface distribution information is a line profile or mapping profile of the photoluminescence intensity.

6. The method of evaluating a silicon wafer according to claim 1, wherein the photoluminescence intensity is a band-edge luminescence intensity.

7. A method of manufacturing a silicon wafer, which comprises:

preparing a silicon wafer lot containing multiple silicon wafers;

extracting at least one silicon wafer from the lot;

evaluating the silicon wafer that has been extracted by the method of evaluating a silicon wafer according to claim 1; and

shipping a silicon wafer as a product wafer, the silicon wafer being within the same lot as the extracted silicon wafer that has been determined to be non-defective in the evaluation.