轻掺杂氢化非晶硅的制备与光电性能研究

Fabrication and Photoelectronic Properties of Boron doped a Si∶H Thin Films

摘要:

采用等离子体化学气相沉积(PECVD)法, 以高纯度硅烷(SiH₄)为反应气体, 硼烷(B₂H₆)为掺杂气体, 在ITO玻璃衬底上制备出硼轻掺杂浓度的氢化非晶硅(a-Si∶H)半导体薄膜。 测量了样品的光暗电导率、折射率、消光系数、禁带宽度随掺杂浓度的变化。结果表明: 随着硼掺杂浓度的增加, 薄膜的暗电导率先减小后增大。消光系数、禁带宽度等都随着掺杂浓度的增加而变化。在不同工艺条件下, 改变硼掺杂浓度, 确定了最佳掺杂比(光暗电导率之比最大), 制备出适合器件级轻掺杂氢化非晶硅薄膜光敏层。

Abstract:

Boron doped a-Si∶H thin films were fabricated by the Plasma Enhanced Chemical Vapor Deposition(PECVD) method on ITO glass substrate, with high purity silane (SiH4) as the reaction gas and borane(B2H6) as the dopant gas. The influence of boron doping amount on conductivity, refractive index, extinction coefficient and band gap were measured. The results show that with the increasing concentration of boron doping amount, the darkness of the films decreases first and then increases. Both the extinction coefficient and the band gap increase and then decreases as the increasing boron doping amount. Without changing the experimental conditions, the optimum doing ratio (the maximum ration of the brightness and darkness of the films) was determined, and then the lightly doped hydrogenated amorphous silicon thin films suitable for device level photosensitive layer were successfully fabricated.