Title :
A novel stack structure to improve the degradation of W-polycide gated MOS device with undoped a-Si/heavily-doped poly-Si multilayer
Author :
Lee, Kan-Yuan ; Fang, Yean-Kuen ; Chen, Chii-Wen ; Liang, Mong-Song ; Hsieh, Jang-Cheng
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
fDate :
5/1/1997 12:00:00 AM
Abstract :
An original structure with undoped amorphous silicon (a-Si)/heavily-doped polysilicon stacked layers is reported. This structure can help to prevent the deterioration of gate oxide caused by fluorine ions in conventional tungsten-polycide (W-polycide) gated MOS devices. The relationship between the thickness of the stacked a-Si layer and the quality of the gate oxide is also investigated. With this W-silicide/a-Si/polysilicon stack structure, a lower sheet resistance of the W-polycide can also be obtained.
Keywords :
MOS capacitors; amorphous semiconductors; annealing; capacitance; characteristics measurement; elemental semiconductors; heavily doped semiconductors; interface states; oxidation; secondary ion mass spectra; semiconductor device metallisation; semiconductor device reliability; silicon; tungsten compounds; MOS capacitor; SIMS profile; W-polycide gated MOS device; W-silicide/a-Si/polysilicon stack structure; WSi-Si; charge-to-breakdown; degradation improvement; furnace annealing; gate breakdown voltage; gate oxide deterioration prevention; gate oxide quality; interface state generation; quasistatic C-V curves; sheet resistance; stacked a-Si layer thickness; undoped a-Si/heavily-doped poly-Si multilayer; Amorphous silicon; Annealing; Boron; CMOS technology; Chemical technology; Doping; MOS devices; Nonhomogeneous media; Propagation delay; Thermal degradation;
Journal_Title :
Electron Device Letters, IEEE
