Method for producing bonded SOI wafer

Patent metadata

Field	Value
Publication number	US-11056381-B2
Application number	US-201615754003-A
Country	US
Kind code	B2
Filing date	Aug 22, 2016
Priority date	Sep 28, 2015
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

A method for producing a bonded SOI wafer by bonding a bond wafer and a base wafer, each being formed of a silicon single crystal, together with a silicon oxide film placed therebetween, the method including: preparing, as the base wafer, a silicon single crystal wafer whose resistivity is 100 Ω·cm or more and initial interstitial oxygen concentration is 10 ppma or less; forming, on the front surface of the base wafer, a silicon oxide film by performing, on the base wafer, heat treatment in an oxidizing atmosphere at a temperature of 700° C. or higher and 1000° C. or lower for 5 hours or more; bonding the base wafer and the bond wafer together with the silicon oxide film placed therebetween; and thinning the bonded bond wafer to form an SOI layer.

First claim

The invention claimed is:

1. A method for producing a bonded SOI wafer by bonding a bond wafer and a base wafer, each being formed of a silicon single crystal, together with a silicon oxide film placed therebetween, comprising:
preparing, as the base wafer, a silicon single crystal wafer whose resistivity is 100 Ω·cm or more, initial interstitial oxygen concentration is 10 ppma or less, and nitrogen concentration is 1×10 13 to 1×10 15 atoms/cm 3 ;
forming, on a front surface of the base wafer, a silicon oxide film for a BOX film whose thickness is 1 μm or more by performing, on the base wafer, heat treatment in an oxidizing atmosphere at a temperature of 700° C. or higher and 1000° C. or lower for 5 hours or more, the heat treatment doubling as annihilation of NO donors associated with nitrogen doping;
bonding the base wafer and the bond wafer together with the silicon oxide film placed therebetween; and
thinning the bonded bond wafer to form an SOI layer.

2. The method according to claim 1 , wherein the resistivity is 1000 Ω·cm or more.

3. The method according to claim 1 , wherein the resistivity is 3000 Ω·cm or more.

4. The method according to claim 1 , wherein the resistivity is 7500 Ω·cm or more.

5. The method according to claim 1 , wherein the nitrogen concentration is 8×10 13 to 1×10 15 atoms/cm 3 .

6. The method according to claim 1 , wherein the method does not include an additional separate heat treatment step for annihilating the NO donors associated with the nitrogen doping.

Assignees

• Shinetsu Handotai Kk

Inventors

• Ishizuka Toru
• Nakano Masatake

Classifications

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P90/12

  Preparing bulk and homogeneous wafers · CPC title

• H10P36/07

  of silicon-on-insulator structures · CPC title

• H10P14/6308

  of Group IV semiconductors · CPC title

• H10W10/181

  Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers · CPC title