Composite substrate manufacturing method, and composite substrate

Patent metadata

Field	Value
Publication number	US-9613849-B2
Application number	US-201314440620-A
Country	US
Kind code	B2
Filing date	Nov 19, 2013
Priority date	Nov 22, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

Disclosed is a composite substrate manufacturing method whereby, after bonding a semiconductor substrate ( 1 ) and a supporting substrate ( 3 ) to each other, the semiconductor substrate ( 1 ) is thinned, and a composite substrate ( 8 ) having a semiconductor layer ( 6 ) on the supporting substrate ( 3 ) is obtained. On the supporting substrate ( 3 ) surface to be bonded, a coating film ( 4 a ) containing polysilazane is formed, a silicon-containing insulating film ( 4 ) is formed by performing firing by heating the coating film ( 4 a ) to 600-1,200° C., then, the semiconductor substrate ( 1 ) and the supporting substrate ( 3 ) are bonded to each other with the insulating film ( 4 ) therebetween, thereby suppressing bonding failures due to surface roughness and defects of the supporting substrate, and easily obtaining the composite substrate.

First claim

The invention claimed is:

1. A method for preparing a composite substrate, comprising the steps of:
coating a polysilazane-containing coating composition on the surface of a support substrate of SiC or GaN to be bonded, to form a polysilazane-containing coating;
subjecting the coating to firing treatment of heating at 600° C. to 1,200° C. to form a silicon-containing insulating film, wherein the insulating film as of firing treatment has a thickness of 10 to 200 nm and a surface roughness Rms of up to 1.0 nm, and thereafter;
bonding a semiconductor substrate to the support substrate via the insulating film, while keeping the thickness of the insulating film as of the firing treatment; and
thinning the semiconductor substrate for thereby yielding the composite substrate having a semiconductor layer on the support substrate.

2. The method for preparing a composite substrate of claim 1 wherein the polysilazane is a perhydropolysilazane.

3. The method for preparing a composite substrate of claim 1 wherein the firing treatment is carried out in an atmosphere containing oxygen and/or steam.

4. The method for preparing a composite substrate of claim 1 , wherein the firing treatment is carried out in an inert atmosphere containing nitrogen or under reduced pressure to convert polysilazane in the coating to SiN.

5. The method for preparing a composite substrate of claim 1 , the method comprising the steps of:
implanting ions into the surface of the semiconductor substrate to form an ion-implanted region; and
separating the semiconductor substrate at the ion-implanted region, thus leaving a semiconductor layer on the support substrate.

6. A composite substrate obtained by the method of claim 1 .

7. The method for preparing a composite substrate of claim 1 , wherein the semiconductor substrate is composed of a material selected from the group consisting of Si, SiGe, SiC, AlN, Ge, GaN, ZnO, and GaAs.

8. The method for preparing a composite substrate of claim 1 , wherein the semiconductor substrate is a single crystal silicon substrate.

9. The method for preparing a composite substrate of claim 1 , wherein the insulating film has a sufficiently smooth surface to enable bonding at the thickness as of firing treatment without a need for polishing the surface of the insulating film.

Assignees

• Shinetsu Chemical Co

Inventors

• Konishi Shigeru
• Shirai Shozo

Classifications

• H10P72/7416

  used during dicing or grinding · CPC title

• H10P72/74

  using temporarily an auxiliary support · CPC title

• H10P50/00

  Etching of wafers, substrates or parts of devices · CPC title

• H10P30/20

  into semiconductor materials, e.g. for doping · CPC title

• H10P14/69215 Primary

  the material being a silicon oxide, e.g. SiO2 · CPC title