弱硼掺杂补偿对氢化微晶硅薄膜制备与特性的影响

Fabrication and Properties of Microcrystalline Silicon Deposited with VHF-PECVD Under Lightly Boron-Doping

研究了弱硼掺杂补偿对甚高频等离子体增强化学气相沉积方法生长氢化微晶硅薄膜(μc-Si∶H)及材料特性的影响.实验发现,随着弱硼补偿剂量的增大,μc-Si∶H薄膜的沉积速率先减小后增加,变化范围约为0.7～0.8nm/s.相比较而言,材料的结晶度以及晶粒的平均颗粒尺寸则呈现出先增后减的变化,且变化的幅度较大,当弱硼补偿剂量大于2.5ppm时,过度的弱硼补偿将导致μc-Si∶H薄膜的结晶状况恶化.此外,光敏性、暗电导及电导激活能的测量结果进一步表明,弱硼补偿显著影响μcSi∶H薄膜的光电特性,弱硼补偿剂量为2.5ppm左右时,材料的光电特性最为理想.因此,优化弱硼补偿剂量是获得器件级质量μc-Si∶H材料的有效途径.

s:The fabrication and properties of μc-Si∶H thin films deposited with VHF-PECVD technique under different lightly boron-doping are investigated.With the increase of dose of B 2H 6-compensation,the deposition rates of μc-Si∶H thin films decrease firstly and then increase in a narrow range(0.7～0.8nm/s).In contrast to deposition rates,the crystalline volume fraction and the average grain size vary more intensively in a reverse way,and the crystallinity of μc-Si∶H thin films is obviously deteriorated as the dose of B 2H 6-compensation exceeds 2.5ppm.The further measurements of photo sensitivity,dark conductivity and active energy E a show that the optical and electrical properties of μc-Si∶H thin films strongly depend on dose of B 2H 6-compensation and here the appropriate dose seems to be 2.5ppm.So the dose of B 2H 6-compensation should be optimized to achieve μc-Si∶H thin films with device-grade quality deposited under VHF-PECVD technique.