HgCdTe光導式偵測器之製作與特性量測

Abstract

本論文是 HgCdTe 光導式紅外線偵測器之製作與特性量測。本實驗是以雙 溫區固態再結晶法所製備之高品質 n-型 HgCdTe 單晶晶片，利用氧化鋁 粉研磨、化學-機械式拋光、化學蝕刻等方法薄化 HgCdTe 晶片，並在晶 片表面以陽極氧化方式成長氧化膜，之後以適當的epoxy與黏著計技術將 HgCdTe 晶片與 sapphire 基板黏接，並以光蝕刻設定光偵測器之幾何結 構，蒸鍍方式製備抗反射膜與歐姆接觸，完成光導式 HgCdTe 紅外線偵測 器。此偵測器置於 77K杜爾瓶，量測偵測器之雜訊、光響度與光偵測度等 特性。我們所製作的紅外線偵測器有效照光面積為1mm*1.5mm，厚度為10 um ，截止波長為 12.4 um ；此偵測器在 0.65 V 的偏壓下對500K黑體輻 射的光響度為2.3E5V/W、光偵測度為 1.4*E9cm*Hz/W。對截止波長 12.4 um 的單一波長光響度經計量修正為 3.9*E5V/W、光偵測度為 2.5E9cm* Hz/W。 In this thesis work, we fabricated and characterized photo- conductive mode HgCdTe infrared (IR) detectors. High-quality n- type HgCdTe ingots were grown by dual-zone solid-state re- crystalization method and were then cut into slices as the starting substrates. The HgCdTe wafers were thinning with alumina lapping, chemical-mechanical polishing, and chemical etching processes to ten's micron thick. The back-sides of the HgCdTe wafers were passivated with anode-oxidization prior to staking to the sapphire substrates. We employed the photolithography and thermal evaporation techniques to deli- neate the detector structures and to prepare the antireflec- tion coating and ohmic contact layers. The area and thickness of the accomplished HgCdTe IR detector were 1.0mmx1.5mm and 10 microns. The detector was examined in liquid-nitrogen dewar for noise, responsivity, and detectivity figures. Under 0.65V bias voltage and 500K black-body radiation conditions,the re- sponsivity and detectivity of the HgCdTe detector were measured to 2.3x105V/W and 1.4x109 cm.Hz1/2/W, respectively. In view of single-wavelength photon excitation at 12.4um, we evaluated the responsivity and detectivity of such detector to be 3.9x105 V/W and 2.5x109 cm.Hz1/2/W.