Title :
A thin amorphous silicon buffer process for suppression of W polymetal gate depletion in PMOS
Author :
Ohtake, F. ; Akasaka, Y. ; Murakoshi, A. ; Suguro, K. ; Nakanishi, T.
Author_Institution :
T Project Group, Fujitsu Labs. Ltd., Japan
Abstract :
The mechanism of gate depletion in PMOS W polymetal (W/WN/sub x//poly-Si) gate was investigated. It was found for the first time that the pile-up of boron (B) occurred at the WN/sub x//poly-Si interface due to B-N formation and the B concentration in poly-Si decreased resulting in gate depletion. In order to prevent the B pile-up, we developed a new process module and succeeded in suppressing the gate depletion without B penetration into Si substrate by using a thin amorphous Si buffer (ASB) layer combined with miniaturization of poly-Si grain-size.
Keywords :
MOSFET; grain size; semiconductor device metallisation; tungsten; PMOS transistor; Si; W polymetal gate depletion; W-WN-Si:B; amorphous silicon buffer layer; boron pile-up; grain size; Amorphous materials; Amorphous silicon; Boron; Capacitors; Electrodes; Laboratories; MOSFETs; Microelectronics; Temperature; Thermal resistance;
Conference_Titel :
VLSI Technology, 2000. Digest of Technical Papers. 2000 Symposium on
Conference_Location :
Honolulu, HI, USA
Print_ISBN :
0-7803-6305-1
DOI :
10.1109/VLSIT.2000.852775