DIFFUSION BARRIER MECHANISM OF EXTREMELY THIN TUNGSTEN SILICON-NITRIDE FILM FORMED BY ECR PLASMA NITRIDATION

Citation
A. Hirata et al., DIFFUSION BARRIER MECHANISM OF EXTREMELY THIN TUNGSTEN SILICON-NITRIDE FILM FORMED BY ECR PLASMA NITRIDATION, JPN J A P 1, 37(3B), 1998, pp. 1251-1255
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Applied
Volume
37
Issue
3B
Year of publication
1998
Pages
1251 - 1255
Database
ISI
SICI code
0021-4922(1998)37:3B<1251:DBMOET>2.0.ZU;2-O
Abstract
The diffusion barrier mechanism of tungsten silicon nitride (WSIN) fil m formed by ECR plasma nitridation is investigated. For this purpose, we examined film thickness, nitrogen content, surface composition, and local atomic ordering of this WSiN and correlated these characteristi cs with its barrier capability. It is revealed that WSIN shows good ba rrier capability when RF bias is applied to the substrate during nitri dation even though it is less than 6-nm thick. Applying RF bias increa ses the nitrogen content in WSiN. Moreover, Si atoms are preferentiall y sputtered and the local atomic ordering in WSiN is lowered because t he effect of ion bombardment is remarkably pronounced. It is supposed that these film characteristics contribute to the suppression of phosp horus diffusion through interstitial sites. As a result, WSiN function s as an excellent barrier layer even though it is extremely thin.