Applied Science and Convergence Technology 1995; 4(3): 301-305
Published online September 1, 1995
Copyright © The Korean Vacuum Society.
Hoi Hwan Chung,Kwan Soo Chung
The electrical characteristics of metal-oxide-semiconductor(MOS) fabricated by polysilicon and tungsten polycide(WSi_x/polysilicon) gate electrodes onto gate oxide grown by wet ambients were evaluated by time zero dielectric breakdown(TZDB). The average breakdown field of the gate oxides with tungsten polycide gate electrode was 1.93 MV/㎝ lower than that of the polysilicon gate electrode. The B mode(1~8 MV/㎝) failure of the gate oxides with tungsten polycide gate electrode was decreased by annealing in dry O₂ ambient. This is attributed to fluorine diffusion in the gate oxide by annealing. The B mode failure of the tungsten polycide gate electrode by dichlorosilane(SiH₂Cl₂) reduction was higher than that of the silane(SiH₄) reduction. It is found that the fluorine concentration in the tungsten silicide film by dichlorosilane was lower than that of the silane reduction.