Simultaneous growth of different thickness gate oxides in silicon CMOS processing

Author

Doyle, Brian ; Soleimani, Hamid R. ; Philipossian, Ara

Author_Institution

Intel Corp., Santa Clara, CA, USA

Volume

16

Issue

7

fYear

1995

fDate

7/1/1995 12:00:00 AM

Firstpage

301

Lastpage

302

Abstract

A method is proposed that allows the growth of gate oxides of different thicknesses on a single wafer. The method does not require masking the gate oxide during oxidation with its inherent risk to the oxide quality, but rather relies on the implant of nitrogen into the silicon wafer before both oxide growth and preoxidation cleans. This implant is performed at the same step as the normal threshold voltage implants, avoiding possible contamination. Using nitrogen implant doses of the order of 3/spl times/10/sup 14/-3/spl times/10/sup 15/ cm/sup -2/, it is shown that it is possible to grow oxides of 30-70 /spl Aring/, for a process with a nominal oxide thickness of 90 /spl Aring/.<>

Keywords

CMOS integrated circuits; elemental semiconductors; integrated circuit technology; ion implantation; nitrogen; oxidation; silicon; 30 to 90 A; CMOS processing; N implant; Si wafer implantation; Si:N; gate oxides; oxidation; simultaneous growth; threshold voltage implants; CMOS process; Circuits; Contamination; Etching; Implants; Microprocessors; Nitrogen; Oxidation; Silicon; Threshold voltage;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.388714

Filename

388714