Title :
1/f noise in poly-Si MOSFET and strong correlation with oxide traps and grain boundaries
Author :
Hashimoto, T. ; Aoki, M. ; Yamanaka, T. ; Kamigaki, Y. ; Nishida, T.
Author_Institution :
Central Res. Lab., Hitachi Ltd., Kokubunji, Japan
Abstract :
The poly-Si MOSFET has become a key device for mega-bit SRAMs. Performance and stability are, however, still insufficient owing to the poor quality of active poly-Si films, gate oxides and their interfaces. We have studied 1/f noise in poly-Si MOSFETs, since this noise measurement is an effective approach to characterizing the MOS interface and gate oxides. We found the noise very strong compared with that in single crystalline-Si (bulk-Si) MOSFETs. It is important to clarify the generation mechanism of such large noise, in order to realize high-performance, high-stability, low-noise devices. In this paper, we introduce a noise-generation mechanism that is characteristic of poly-Si MOSFETs. It is related to the quality of gate oxides and poly-Si films, that is, the oxide trap and grain boundary properties. Also we explain a method for reducing the noise. Furthermore, we demonstrate that the 1/f noise measurement is very useful for process monitoring.<>
Keywords :
electron traps; elemental semiconductors; grain boundaries; hole traps; insulated gate field effect transistors; random noise; semiconductor device noise; semiconductor-insulator boundaries; silicon; 1/f noise measurement; MOS interface; Si-SiO/sub 2/; active polysilicon films; generation mechanism; grain boundaries; noise generation mechanism; oxide traps; poly-Si MOSFET; process monitoring; stability; Annealing; Grain boundaries; Grain size; Low-frequency noise; MOSFET circuits; Noise level; Noise measurement; Noise reduction; Paramagnetic resonance; Power MOSFET;
Conference_Titel :
VLSI Technology, 1994. Digest of Technical Papers. 1994 Symposium on
Conference_Location :
Honolulu, HI, USA
Print_ISBN :
0-7803-1921-4
DOI :
10.1109/VLSIT.1994.324442
