Effect of annealing ambient on WSix(x=2.3) sidewall deformation and contact resistance in dichlorosilane-based W-polycide gate

Citation
Sw. Park et al., Effect of annealing ambient on WSix(x=2.3) sidewall deformation and contact resistance in dichlorosilane-based W-polycide gate, J VAC SCI B, 19(4), 2001, pp. 1186-1194
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
ISSN journal
1071-1023 → ACNP
Volume
19
Issue
4
Year of publication
2001
Pages
1186 - 1194
Database
ISI
SICI code
1071-1023(200107/08)19:4<1186:EOAAOW>2.0.ZU;2-K
Abstract
To analyze the deformation of the WSix sidewall in a W-polycide gate, WSix( x=2.3) film was deposited by a modified dichlorosilane (SiH2Cl2, DCS) proce ss that consisted of in situ monosilane (SiH4, MS)-based WSix nucleation, f ollowed by DCS-based WSix deposition at 550 degreesC. Compared to the conve ntional DCS-based WSix film, the WSix film did not exhibit a W-rich interfa ce facilitating the deformation and it showed similar structural property. Examination of deformation dependence on heat-treatment ambients suggested that a deformed region having a detrimental morphology was formed at the WS ix sidewall during both nonoxidizing and oxidizing ambient annealings. It w as revealed that the deformation in nonoxidizing and oxidizing ambient anne aling resulted from the formation of a Si precipitate and W-Si-O compound a t the WSix sidewall, respectively. In the case of N-2 ambient preannealing at 600 degreesC for 30 min in the process of spacer oxide deposition, the d eformation could be effectively suppressed by preventing the formation of S i precipitate at the WSix sidewall. The N-2 ambient preannealing also impro ved the contact resistance of metal (Al/W plug with TiN/Ti barrier) on the W-polycide gate by promoting silicidation between Ti and excess Si in the W Six layer. (C) 2001 American Vacuum Society.