(n)nc-Si：H/(p)c-Si异质结中载流子输运性质的研究

采用常规等离子体增强化学气相沉积工艺，以高H₂稀释的SiH₄作为反应气体源和PH₃作为磷原子的掺杂剂，在p型(100)单晶硅((p)c-Si)衬底上， 成功地生长了施主掺杂型纳米硅膜((n)nc-Si:H)，进而制备了(n)nc-Si:H/(p)c-Si异质结，并在230—420Ｋ温度范围内实验研究了该异质结的Ｉ-Ｖ特性.结果表明，(n)nc-Si:H/(p)c- Si异质结为一典型的突变异质结构，具有良好的温度稳定性和整流特性.正向偏压下 关键词： (n)nc-Si:H/(p)c-Si异质结 能带模型 电流输运机构 温度特性

CARRIER TRANSPORT PROPERTIES OF THE (n)nc-Si:H/(p)c-Si HETEROJUNCTION

Phosphor-doped nano-crystalline silicon ((n))nc-Si:H) films are successfully gro wn on the p-type (100) oriented crystal silicon ((p) c-Si) substrate by conventi onal plasma-enhanced chemical vapor deposition method. The films are obtained us ing high H₂ diluted SiH₄ as a reaction gas source and usin g PH₃ as the doping gas source of phosphor atoms. Futhermore, the het erojunction diodes are also fabricated by using (n)nc-Si:H films and (p)c-Si sub strate. I-V properties are investigated in the temperature range of 230—420K. T he experimental results domenstrate that (n)nc-Si:H/(p)c-Si heterojunction is a typical abrupt heterojunction having good rectifing and temperature properties. Carrier transport mechanisms are tunneling-recombination model at forward bias v oltages. In the range of low bias voltages (V_F<0.8V), the current is determined by recombination at the (n)nc-Si:H side of the space charge region, w hile the current becomes tunneing at higher bias voltages(V_F>1.0V). The present heterojunction has high reverse breakdown voltage (>-75V) and low re verse current (≈nA).