本研究主要是探討選擇性濕式蝕刻技術應用在量子井紅外線光偵檢器上之光電特性分析。主要針對兩個研究課題來進行研究：如何提升光柵蝕刻的精準度與絕對光響應度之校正。此外，我們也利用所提出之高選擇比之蝕刻配方來薄化FPA背面基板，以得到較佳之影像品質。
第一部份在如何提升光柵蝕刻的精準度的研究中，因為光柵的蝕刻深度為影響量子井紅外線光偵檢器光響應度之重要因素，我們藉由選擇性濕式蝕刻方式搭配蝕刻停止層的方法，使光柵蝕刻深度更為精準，解決了先前配方無法精準蝕刻至我們所設計深度之問題，進而提升光響應度。
第二部份因元件光電特性之優劣需以絕對光響應度來作分析比較，我們提出一套方法來驗證出量子井紅外線光偵檢器之校正因子，使得從FTIR所量測出之相對光響應度可直接轉換成我們所需之絕對光響應度。
第三部份我們利用所提出之高選擇比的蝕刻配方來薄化FPA背面基板，解決了因基板未薄化會引起光學串音失真及降溫時FPA與ROIC之間因熱應力而產生之脫層壞點和影像劣化的問題。

In this study, we have investigated the selective wet etching technology applied on quantum well infrared photodetector (QWIP) for optical property analysis. The study focused on two major issues: one is the accuracy improvement of the etching process for optical grating pattern and the other is the calculation for absolute responsivity. In addition, we also used the proposed high selectivity etching recipe to remove the FPA substrate to achieve the better thermal imaging.
Because the etching depth of optical grating pattern is an important factor for the responsivity of quantum well infrared photodetector, we used selective wet-etching process with etching stop layer to make the etching depth of optical grating pattern more precise. The proposed method not only solves the problem that previous recipe doesn’t work because the depth of our design couldn’t be approached precisely by normal etching solutions but also enhances the spectral response for the QWIP device.
Furthermore, we proposed the modified method to achieve the correction factor that converts the relative responsivity measured from Fourier Transform Infrared Spectrometer (FTIR) into the absolute responsivity because the absolute responsivity is an important parameter to assess the QWIP performance.
Finally, we used the high selectivity etching recipe to remove the FPA substrate. It solves the problem that the thicker substrate would cause distortion of the optical crosstalk and the delamination between the FPA and ROIC due to thermal stress generated under cooling cycles to result in dead pixels and worse imaging.

誌謝 ii
摘要 iii
ABSTRACT iv
目錄 v
表目錄 viii
圖目錄 ix
1. 緒論 1
1.1 研究背景 1
1.2 研究動機 3
1.3 論文架構 3
2. 理論介紹 5
2.1 選擇性濕式蝕刻 5
2.1.1 蝕刻原理 5
2.1.2 技術背景 7
2.2 光電特性 11
2.2.1 光響應度 11
2.2.2 暗電流 11
2.2.3 背景光電流 13
2.2.4 雜訊電流 14
2.2.5 偵測度 16
2.2.6 非均勻度 16
2.2.7 雜訊等效溫度差 17
2.3 光柵設計 18
2.4 FPA基板蝕刻效能 20
3. 實驗方法與實驗架設 21
3.1 選擇比驗證實驗方法 21
3.2 元件光柵蝕刻實驗方法 23
3.3 元件製備 25
3.4 光響應度量測 27
3.5 絕對光響應度校正 28
3.6 暗電流及背景光電流量測 30
3.7 雜訊電流量測 31
3.8 FPA基板背面蝕刻實驗架構 33
4. 結果與討論 36
4.1 絕對光響應校正結果 36
4.2 選擇比驗證結果 46
4.3 元件光柵蝕刻實驗結果 53
4.3.1 光響應度量測結果 53
4.3.2 暗電流量測結果 57
4.3.3 活化能分析 60
4.3.4 偵測度分析 63
4.3.5 光導增益 g、量子效率η及載子被捕捉機率 pc之分析 68
4.4 比較與討論 69
4.4.1 檸檬酸配方與氨水配方蝕刻光柵效果之比較 69
4.4.2 FPA蝕刻前後之影像品質、非均勻度及NEDT之比較 72
5. 結論與建議 80
參考文獻 82
自傳 86

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