Process for fabricating SOI substrate

• US 5,863,829 A
• Filed: 11/13/1996
• Issued: 01/26/1999
• Est. Priority Date: 08/24/1995
• Status: Expired due to Fees

• Current Assignee: Komatsu Electronic Metals Co., Ltd. (Sumco Corporation)
• Original Assignee: Komatsu Electronic Metals Co., Ltd. (Sumco Corporation)
• Inventors: Ishii, Akihiro, Nakayoshi, Yuichi, Yamamoto, Hiroaki
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): ALANKO, ANITA KAREN
• Application Number:
  US08/748,406
• Time in Patent Office: 804 Days
• Field of Search: 438/459, 438/690, 438/704, 438/734, 438/977, 438/409, 216/36, 216/20, 216/53, 216/57, 216/79, 148/DIG. 12
• US Class Current: 438/459
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate

Abstract

The present invention provides a process for fabricating an SOI substrate with no peripheral scratches and with enhanced fabrication efficiency. The present process includes bonding a semiconductor wafer of an active substrate 1 and a semiconductor base wafer 2 to form a bonded wafer 4; surface-grinding the active substrate 1; spin etching the surface-ground active substrate 1; and PACE processing the etched active substrate 1 to form the active substrate into a thin film and simultaneously, to remove the non-bonded peripheral portion of the bonded wafer 4.

Claims

1. A process for fabricating an SOI substrate, comprising subjecting a bonded wafer, in which the bonded wafer is composed of a semiconductor wafer of an active substrate bonded on by a semiconductor base wafer, to PACE (plasma assisted chemical etching) process to form the active substrate into a thin film so as to obtain the SOI substrate, characterized in that a non-bonded peripheral portion of the bonded wafer is simultaneously removed by the PACE process.

2. A process for fabricating an SOI substrate, characterized in that the process comprises the following steps of:

(1) bonding a semiconductor wafer of an active substrate and a semiconductor base wafer to form a bonded wafer;

(2) surface-grinding the active substrate of the bonded wafer;

(3) etching the surface-ground active substrate by spin etching; and

(4) PACE processing the etched active substrate to form the etched active substrate into a thin film and simultaneously to remove a non-bonded peripheral portion of the bonded wafer.

3. The process for fabricating an SOI substrate as. claimed in claim 2, wherein an etching solution used in the spin etching is a mixed acid.

4. The process for fabricating an SOI substrate as claimed in claim 3, wherein the mixed acid comprises hydrofluoric acid, nitric acid, n-phosphoric acid and sulfuric acid.