臺灣博碩士論文加值系統

本論文利用電漿助長化學氣相沉積法(PECVD)，在單晶矽基板上成長非晶
矽鍺材料，以研製非晶矽鍺/單晶矽異質接面之快速紅外線光檢測器。由
於單晶矽具有低阻值、高移動率的特性； 而非晶矽具有低溫製程、高光
吸收效率、可大面積製造與價格便宜的特性。本實驗即結合兩者之優點，
成功地製造出響應速度較傳統非晶矽鍺光檢測器快，且成本較單晶矽結
低的紅外線異質接面光檢測器。在同樣摻雜濃度和厚度的i-a-Si0.6
Ge0.4:H和n-a-Si:H條件下，本實驗元件的主要結構為Al/n-a-Si:H/i-a-
Si0.6Ge0.4:H/p-c-Si與傳統非晶矽鍺結構相比較，具有以下三項優點：
1.吸收波長峰值移至更長波長處(本元件之吸收波長峰值 865nm，而傳統
非晶矽鍺結構之吸收波長峰值為710nm)。 2.較快之響應速度(本元件之上
升時間為195μs，而傳統非晶矽鍺結構之上升時間為465μs)。 3.暗電流
大幅降低(在5V的反偏下，本元件之暗電流約3.3μA，而非晶矽鍺結構之
暗電流約50μA)。

In this thesis , the amorphous silicon-germanium / crystal
silicon heterojunction high-speed IR photodetector was
studied in detail. In preparing the samples , the amorphous
silicon- germanium alloys were grown on the crystal silicon
subtrate by plasma enhanced chemical vapor deposition (PECVD).
Both advantages of the low resistivity and high mobility
characteristics of crystal silicon and the low temperature
preparation processing,high optical absorption ,large area
device feasibility and low cost of amorphous silicon are
employed to prepare the heterojunction structure
photodetector for faster response speed and lower cost.
Compared with the traditoinal amorphous silicon germanium
structure,the device with the structure of Al/n-a-Si:H/i-a-
Si0.6 Ge0.4:H/p-c-Si has the following advantages: 1.The
absorption wavelength peak moves to a higher value(865 nm )
than that 710 nm of the traditional amorphous silicon
germanium structure. 2.The device has a faster response speed
( with a rise time of 195μs ) than that ( with a rise
time of 465μs ) of the traditional amorphous silicon germanium
structure . 3.The dark current has been decreased to a lower
value (3.3μA under a reverse bias of 5V ) than that ( 50μA
under the same bias)of the amorphous silicon germanium
structure.