Semiconductor epitaxial wafer

• US 9,397,172 B2
• Filed: 07/14/2015
• Issued: 07/19/2016
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Kadono, Takeshi
• Primary Examiner(s): Geyer, Scott B
• Application Number:
  US14/799,435
• Publication Number:
  US 20160013278A1
• Time in Patent Office: 371 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 27/14687 Wafer level processing
• CPC Class Codes: H01L 29/167 further characterised by the doping material H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/36 characterised by the concentration or distribution of impurities in the bulk material within semiconductor regions H01L29/06

Abstract

Provided is a semiconductor epitaxial wafer with reduced metal contamination achieved by higher gettering capability. The semiconductor epitaxial wafer includes a silicon wafer including COPs; a modifying layer formed from a certain element in the silicon wafer, in a surface portion of the silicon wafer; and an epitaxial layer on the modifying layer, wherein the full width half maximum of a concentration profile of the certain element in the depth direction of the modifying layer is 100 nm or less.

Claims

1. A semiconductor epitaxial wafer comprising:

a silicon wafer including COPs;

a modifying layer formed from a certain element in the silicon wafer, in a surface portion of the silicon wafer; and

an epitaxial layer on the modifying layer,

wherein the full width half maximum of a concentration profile of the certain element in the depth direction of the modifying layer is 100 nm or less.

2. The semiconductor epitaxial wafer according to claim 1, wherein the maximum size of the COPs is 0.25 μ

m or less.

3. The semiconductor epitaxial wafer according to claim 1, wherein the peak of the concentration profile in the modifying layer lies at a depth within 150 nm from the surface of the silicon wafer.

4. The semiconductor epitaxial wafer according to claim 1, wherein the peak concentration of the concentration profile of the modifying layer is 1 ×

10¹⁵ atoms/cm³ or more.

5. The semiconductor epitaxial wafer according to claim 1, wherein the certain element includes carbon.

6. The semiconductor epitaxial wafer according to claim 5, wherein the certain element includes at least two kinds of elements including carbon.