由於光纖通訊的蓬勃發展，使得光接收器的需求大增，過去大部分的光接收器都是採用三五族半導體材料，但此材料在矽質光電積體電路製程整合上頗困難，若能以目前產業主流的矽材質製作，則此整合性的問題即可迎刃而解。 本論文探討含非晶矽化鍺氫梯度結構薄膜的金屬-半導體-金屬光偵測器特性。藉調整梯度結構層沉積的時間與溫度及利用氫氣退火等研究所製作的各種金屬-半導體-金屬光偵測器的交、直流特性。再者，利用自動對準製程完成溝渠式電極光偵測器並探討其特性。最後，利用金屬-半導體-金屬光偵測器的結構研發出低操作電壓之大工作面積光偵測器，以利實際運用的探討。 In this thesis, first, the metal-semiconductor-metal photodetectors (MSM-PDs) with a graded hydrogenated intrinsic amorphous silicon-germanium (i-a-Si1-xGex:H) film deposited on  n-type silicon wafer, and the Cr top-electrodes have been studied. The effects of elapsed-time during growing graded i-a-Si1-xGex:H layer, substrate temperature and H2-annealing on device characteristics were compared and discussed. Then, the fabrication process and characteristics of the MSM-PDs with self-aligned trench-electrodes were investigated. Their obtainable characteristics were nearly the same as those of a conventional MSM-PD with trench-electrodes, which needed an additional mask. Finally, instead of i-a-Si1-xGex:H film, the i-a-Si:H film was used and deposited on Si wafer to form MSM-PDs with large active-area. The effects of resistivity of Si wafer on device performances were also discussed. The device linearity, knee voltage, and dark current were studied.