nc-Si∶H/c-Si量子点二极管中的共振隧穿特性分析

Analysis of Resonant Tunneling Characteristics in nc Si∶H/c Si Quantum Dot Diode

采用常规ＰＥＣＶＤ工艺，在Ｎ型单晶硅（ｃ－Ｓｉ）衬底上沉积薄层纳米Ｓｉ（ｎｃ－Ｓｉ）膜，并进而制备了ｎｃ－Ｓｉ∶Ｈ／ｃ－Ｓｉ量子点二极管．在１０～１００Ｋ温度范围内实验研究了该结构的σ－Ｖ和Ｉ－Ｖ特性．结果指出，当反向偏压为－７～－９Ｖ时，无论在σ－Ｖ还是在Ｉ－Ｖ特性曲线上都观测到了近乎等间距的量子化台阶，此起因于在ｎｃ－Ｓｉ∶Ｈ膜中具有无序排布且粒径大小不一的Ｓｉ微晶粒中，由于微晶粒中能级的量子化而导致的共振隧穿现象．如果进一步改进膜层生长工艺，以制备出具有趋于有序排布、尺寸均匀和粒径更小的Ｓｉ微晶粒的ｎｃ－Ｓｉ∶Ｈ膜，有可能实现更高温度范围内的共振隧穿．

Abstract Nanometer crystalline silicon(nc Si∶H) films are grown on the n type crystal silicon (c Si) substrate by conventional PECVD, and nc Si∶H/c Si quantum dot diode is also fabricated. The σ V and I V properties of this structure are experimentally studied at temperatures ranging from 10～100K. Quantum staircase on both σ V and I V characteristics are observed when negative bias voltage is -7～-9V. This results from resonant tunneling phenomenon of nanometer silicon microcrystalline in nc Si∶H films. Here, quantization of energy level in Si microcrystalline particle plays an important part in resonant tunneling process. If quality of nc Si∶H films is improved, resonant tunneling phenomenon could be achieved at higher temperature, so that nc Si∶H films have potential applications in new quantum functional devices.