SURFACE-STATE GENERATION OF MO GATE METAL-OXIDE-SEMICONDUCTOR DEVICESCAUSED BY MO PENETRATION INTO GATE OXIDE

Citation
T. Amazawa et H. Oikawa, SURFACE-STATE GENERATION OF MO GATE METAL-OXIDE-SEMICONDUCTOR DEVICESCAUSED BY MO PENETRATION INTO GATE OXIDE, Journal of the Electrochemical Society, 145(4), 1998, pp. 1297-1303
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
ISSN journal
0013-4651
Volume
145
Issue
4
Year of publication
1998
Pages
1297 - 1303
Database
ISI
SICI code
0013-4651(1998)145:4<1297:SGOMGM>2.0.ZU;2-5
Abstract
The surface states of molybdenum (Mo) gate metal oxide semiconductor ( MOS) devices have been examined and Mo penetration into the Si-SiO2 in terface during Mo film deposition has been confirmed to be one of: the causes of surface state generation. Penetration of Mo atoms occurs wh en the substrate is heated during deposition by sputtering or electron -beam evaporation. The mechanism responsible for the penetration is as sumed to be caused by Mo ions on the SiO2 surface during the initial s tages of deposition. To prevent this Mo penetration, a very thin Mo fi lm is first deposited at room temperature to form a conductive layer, and a thick Mo film is subsequently deposited at high temperature. By applying this two-step deposition method, the penetration depth of Mo into the SiO2 can be reduced to less than 3 nm and the surface state d ensity can be reduced to below 3 x 10(10) cm-(2) eV(-1) even in MOS de vices with a gate oxide thickness of 10 nm.