热丝化学气相沉积技术低温制备多晶硅薄膜的结构与光电特性

Structual and optoelectronic properties of polycrystalline silicon thin films prepared by hot-wire chemical vapor deposition at low temperatures

以金属W和Ta为热丝 ,采用热丝化学气相沉积 ,在 2 5 0℃玻璃衬底上沉积多晶硅薄膜 .研究了热丝温度、沉积气压、热丝与衬底间距等沉积参数对硅薄膜结构和光电特性的影响 ,在优化条件下获得晶态比Xc>90 % ,暗电导率σd=10 - 7— 10 - 6 Ω- 1 cm- 1 ,激活能Ea=0 5eV ,光能隙Eopt≤ 1 3eV的多晶硅薄膜 .

Polycrystalline silicon thin films were prepared by hot-wire chemical vapor deposition ( HWCVD) on glass at 250 degreesC with W or Ta wire as the catalyzers. The structual and optoelectronic properties as functions of the filament temperature, deposition pressure and the filament-substrate distance were studied, and the optimized polycrystalline silicon thin films were obtained with X-c > 90 % ( X-c denotes the crystalline ratio of the film), crystal grain size about 30-40nm, R-d approximate to 0.8nm/s, sigma(d) about 10(-7) - 10(-6) Omega(-1) cm(-1), Ea(a) approximate to 0.5eV and E-opt less than or equal to 1.3eV.