矽基金屬半導體光偵測器製作與紅外光量測系統架構之研究

Abstract

在物質生活快速發展的年代，人們享受方便舒適科技化的生活模式，例如出門只需帶著手機而不用帶錢包就可以進行小額支付，但科技化的環境附帶而來的則是工業汙染、全球暖化、資源匱乏等相關議題，進而使人們逐漸開始重視我們所生活的環境周遭，空氣汙染、PM2.5等環境問題漸漸變得不可忽視且須謹慎看待，為了因應這樣的環境變化，即時偵測便顯得至關重要。市面上氣體偵測設備多半體積過於龐大不易攜帶，而體積小的設備則靈敏度不足，且價格高昂，對於一般民眾無法負擔，因此本論文意在開發一種紅外光偵測器，有利於隨身攜帶、偵測種類多元且精準度高之微型光譜儀系統。 本論文主要目標為開發寬頻紅外光偵測，搭配矽基金屬半導體二極體技術之偵測器來量測寬頻紅外光，嘗試不同入射方式以及矽基板類型，而成功研發出穩定電性表現、電流差值小且在1550nm光源下有非常高的光電響應之紅外光偵測器。接著我們導入局域表面電漿共振的原理，利用正立金字塔結構以下之特點：具備由頂端至底部之橫向寬度由窄至寬的優點使不同入射光波長對應不同共振位置而可以達到寬頻偵側，並且由COMSOL模擬軟體進行模擬驗證實驗結果，我們使用RIE乾式蝕刻以及KOH濕式蝕刻成功製作出4微米、6微米以及8微米之正立金字塔結構陣列，並優化製程參數，改良元件製程步驟。最後我們將金屬半導體光偵測器與金字塔結構結合，在1550nm入射光波下以週期6微米之正立金字塔元件有最好的響應，響應值為2.5301mA/W。而在3.22μm以及4.16μm光源波段，利用金字塔腔體侷限能量的效應，藉由電場在金字塔腔壁上來回共振並偵側所產生之熱能及光能量，分別於8微米及6微米金字塔元件觀察到最好的響應結果。

In the era of rapid development of high-tech and convenient life, people enjoy comfortable technology, such as going out with a mobile phone instead of using a wallet to make small payments, but the technological environment comes with industrial pollution, the world important issues such as warming and lack of resources have led people to gradually pay attention to the environment around which we live. Environmental problems such as air pollution and PM2.5 have gradually become unnegligible. In response to such environmental changes, instant detection is crucial. Most of the gas detection equipment on the market is too heavy to carry, and the small size equipment is not sensitive enough, and the price of both are too high, which is unaffordable for the general public. Therefore, this paper intends to develop an infrared light detector, which is convenient for carrying and highly accurate miniature spectrometer system. The main goal of this thesis is to develop broadband infrared light detection, with Si-based metal-semiconductor diode technology to measure broadband infrared light, try different incident modes and silicon wafer type, and successfully develop an infrared detector with stable electrical performance, small current fluctuation and a very high photo-response at 1550 nm laser signal. Then we introduce the principle of local surface plasma resonance(LSPR), using the following characteristics of the upright pyramid structure: the advantage is having a lateral width from the top to the bottom is narrow to wide, so that different incident light wavelengths correspond to different resonance positions, and broadband detection can be achieved. And the results of simulation can verify experiments by COMSOL simulation software, we successfully fabricated 4 micro-meters, 6 micro-meters and 8 micro-meters upright pyramid structure arrays using RIE dry etching and KOH wet etching, and optimized process parameters and improve process steps. Finally, we combine a metal-semiconductor photodetector with a pyramid structure to have the best response with a 6-micron upright pyramid device at 1550 nm incident light, with a response of 2.53 mA/W. In the 3.22μm and 4.16μm source bands, using the effect of the confined energy in pyramid cavity, the electric energy generated by the electric field resonating back and forth on the pyramid wall. The best response are observed in the 8-micron and 6-micron pyramid device respectively.