在本研究中，我們在矽晶基材上利用奈米球微影技術結合金屬催化蝕刻法以一步驟蝕刻來製備大面積之規則矽單晶奈米錐陣列，並將製程技術發展，成功於基材兩面製備出雙面型矽單晶奈米錐結構試片。接著蒸鍍鎳金屬薄膜於奈米錐側壁上，透過熱退火處理使鎳金屬與矽基材反應生成鎳矽化物，並藉由相鑑定得知為二鎳化矽結構。透過光譜儀量測上述結構可發現，鎳金屬可大幅改善矽基材近紅外光波段吸收性，且經由退火製程形成鎳矽化物後又可再次提升，而雙面型奈米錐試片的背部結構會增加整體光學穿透率，若同時於正面製備成異質結構，單面型奈米錐試片在紅外光波段會具有較佳的吸收率，加入背電極鋁後於1200-1600 nm波長範圍平均吸收率可達95%。進一步量測結構的光感測性質發現，在940 nm近紅外光源照射下，鎳/矽奈米錐/矽製備成鎳矽化物/矽奈米錐/矽結構可提升其響應光電流，而鎳矽化物/矽奈米錐/矽/矽奈米錐結構反應出較低的暗電流，但光電流也同時下降。對最高響應光電流的鎳矽化物/矽奈米錐/矽結構做響應度與響應時間量測，該元件表現出不錯的響應速度，且各結構元件均可於零偏壓下運作，實現了自驅動光感測的特性。;In this study, we based on the nanosphere lithography and one-step Au-assisted chemical etching process to fabricate single-sidde and double-sided vertically-aligned Si nanocone arrays on p-type (001) Si substrates. In order to enhance the near-infrared absorption, Ni thin film was deposited on the sidewall of the Si nanocone and followed by silicide process. The TEM and SAED analysis indicated that the formation of silicide phase is single-crystalline NiSi_2. UV-Vis-IR spectroscopic measurements showed that Ni thin film can dramatically improve the near-infrared absorption. If Ni thin film become to NiSi_2 thin film by silicide process, it showed the higher absorptance than Ni thin film, which have promising applications in near-infrared photodetector. The produced Ni or NiSi_2/Si nanocone heterostructure exhibited rectification property by Schottky contact and generated photocurrent under 940 nm illumination at zero bias voltage. The obtained results presented a novel structure of Si-base near-infrared photodetector. It has high light trapping ability, fast response and operation in zero bias. This work offer a relative cheap and fast process compared with other Si-base near-infrared photodetectors.
