透明電極之雪崩型感光二極體製作及特性研究

Investigation and Fabrication of Avalanche Photodiodes with Transparent Electrode

陳梓育(Tzu-yu Chen)

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2006年)

摘要

雪崩型光偵測器具有高內部增益且靈敏度高之特性，適合應用於長距離的光纖通訊系統。本論文主要是探討以砷化銦鋁鎵為雪崩型光偵測器之倍增材料，砷化銦鎵為吸收層材料，考慮材料的特性及接面間的電場分佈，設計各磊晶層最佳化厚度及濃度。根據理論計算，吸收層最佳化厚度為1.1~1.5μm，濃度＜1×1016cm-3，異質接面電場＜2×105V/cm，可有效抑制暗電流產生。
利用高溫爐控制鋅擴散時間長短及溫度來決定擴散深度，即元件的p+區域，再利用透明導電膜銦錫氧化膜的高導電性及高光穿透率等特性，取代傳統電極結構，並將之應用於雪崩型感光二極體上，期許能夠避免金屬對光的遮蔽效應等問題，以提升雪崩型感光二極體之特性，最後對雪崩型光偵測器元件進行特性分析，其中包含電流-電壓特性分析、雪崩增益及其他運算等。

並列摘要

Avalanche photodiodes have the properties of high internal gain and high sensitivity. Therefore, it can be popularly applied in long-haul fiber communication system. In this thesis, we investigated the performance of the avalanche photodiodes that used InAlGaAs as multiplication layer and InGaAs as absorption layer. We also considered the characteristic of material and electric field of interface and designed the optimum thickness and concentration of epilayer in this device structure. According to the theory, the optimum thickness of absorption layer is from 1.1 to 1.5μm and the concentration is smaller than 1×1016 cm-3. The optimum electric field of heterojunction interface is smaller than 2×105V/cm, and its can effectively suppress the dark current.
In this thesis, we treated the sample with the diffusion time and temperature used the furnace system to decide the junction depth of the P+ type. We used the Indium Tin Oxide (ITO) to replace the convention electrode. Expect that be able to avoid the electrode cover the light, improve the performance of avalanche photodiode. Finally, we fabricated the avalanche photodiodes and discussed the performance of the I-V curves, multiplication gains and other operation, etc..

參考文獻

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