Title :
Sputtered Ta-Si-N diffusion barriers in Cu metallizations for Si
Author :
Kolawa, E. ; Pokela, P.J. ; Reid, J.S. ; Chen, J.S. ; Ruiz, R.P. ; Nicolet, Marc A.
Author_Institution :
California Inst. of Technol., Pasadena, CA, USA
fDate :
6/1/1991 12:00:00 AM
Abstract :
Electrical measurements on shallow Si n/sup +/-p junction diodes with a 30-nm TiSi/sub 2/ contacting layer demonstrate that an 80-nm-thick amorphous Ta/sub 36/Si/sub 14/N/sub 50/ film prepared by reactive RF sputtering of a Ta/sub 5/Si/sub 3/ target in an Ar N/sub 2/ plasma very effectively prevents the interaction between the Si substrate with the TiSi/sub 2/ contacting layer and a 500-nm Cu overlayer. The Ta/sub 36/Si/sub 14/N/sub 50/ diffusion barrier maintains the integrity of the I-V characteristics up to 900 C for 30-min annealing in vacuum. It is concluded that the amorphous Ta/sub 36/Si/sub 14/N/sub 50/ alloy is not only a material with a very low reactivity for copper, titanium, and silicon, but must have a small diffusivity for copper as well.<>
Keywords :
copper; elemental semiconductors; metallisation; p-n homojunctions; semiconductor-metal boundaries; silicon; sputtered coatings; tantalum compounds; titanium compounds; 30 to 500 nm; 900 C; Cu metallizations; Cu-TiSi/sub 2/-Ta/sub 36/Si/sub 14/N/sub 50/-Si; I-V characteristics; Si substrate; Ta/sub 36/Si/sub 14/N/sub 50/ diffusion barrier; amorphous Ta/sub 36/Si/sub 14/N/sub 50/ film; annealing in vacuum; diffusion barriers; reactive RF sputtering; shallow Si n/sup +/-p junction diodes; silicides; Amorphous materials; Argon; Contacts; Copper; Diodes; Electric variables measurement; Metallization; Radio frequency; Semiconductor films; Sputtering;
Journal_Title :
Electron Device Letters, IEEE
