Suppression of cobalt silicide agglomeration using nitrogen (N/sub 2//sup +/) implantation

Author

Sun, Wein-Town ; Liaw, Ming-Chi ; Hsu, Charles Ching-Hsiang

Author_Institution

Microelectron. Lab., Nat. Tsing Hua Univ., Hsinchu, Taiwan

Volume

19

Issue

5

fYear

1998

fDate

5/1/1998 12:00:00 AM

Firstpage

163

Lastpage

166

Abstract

In this paper, the effects of nitrogen coimplantation with boron into p/sup +/-poly gate in PMOSFETs on the agglomeration effects of CoSi/sub 2/ are studied. The thermal stability of CoSi/sub 2//poly-Si stacked layers can be significantly improved by using nitrogen implantation. Samples with 40-nm cobalt silicide (CoSi/sub 2/) on 210-nm poly-Si implanted by 2/spl times/10/sup 15//cm/sup 2/ N/sub 2//sup +/ are thermally stable above 950/spl deg/C for 30 s in N/sub 2/ ambient. If the dose of nitrogen is increased up to 6/spl times/10/sup 15//cm/sup 2/, the sheet resistance of CoSi/sub 2/ film is not increased at all, and TEM photographs show that the agglomeration of CoSi/sub 2/ film is completely suppressed.

Keywords

MOSFET; boron; cobalt compounds; elemental semiconductors; ion implantation; nitrogen; semiconductor device metallisation; silicon; thermal stability; 210 nm; 30 s; 40 nm; 950 degC; CoSi/sub 2/-Si:B,N/sub 2/; PMOSFET; TEM; coimplantation; p/sup +/-poly gate; sheet resistance; silicide agglomeration; thermal stability; Boron; Cobalt; Conductivity; MOSFET circuits; Nitrogen; Rapid thermal annealing; Silicides; Sun; Thermal degradation; Thermal stability;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.669736

Filename

669736