用椭偏法研究掺磷a-Si∶H薄膜的光学特性

Study on the Optical Properties of P-doped a-Si∶H Thin Films by Spectroscopic Ellipsometry

用等离子体增强化学气相沉积（PECVD）方法制备了磷掺杂氢化非晶硅（a—Si：H）薄膜。分别以50°和70°为入射角，测试了样品在300-1000nm波长的椭偏光谱，得到了其膜厚和光学常数谱（折射率和消光系数随波长变化谱），并应用Tauc作图法推算出了薄膜的光学带隙。

Hydrogenated amorphous silicon（a-Si ： H） thin films doped with phosphor （P） were deposited by plasma enhanced chemical vapor deposition （PECVD）. The ellipsometric spectra of the testing thin films were measured at either 50° or 70°incident angle under 300 1 000 nm wavelength range, upon which the thickness and the optical constants（refractive index and extinction coefficient） of the films were also obtained. The optical band gap of the testing films was estimated following the procedure of Tauc.