臺灣博碩士論文加值系統

本論文提出P+-Si/MQW-(SiGe/Si)/i-SiGe/N+-Si光吸收-累崩分離結構的二極體光檢測器，SiGe/Si的量子井結構是以超高真空化學氣相沉積系統所成長。此樣品的PL峰值波長約為1200nm與1500nm顯示分別為Si與SiGe。
目前尚未有光吸收-累崩分離結構的SiGe元件提出。本論文提出了P+-Si/MQW-(SiGe/Si)/i-SiGe/N+-Si光吸收-累崩分離結構的二極體光檢測器，期望光檢測器在照光後能由i-SiGe層吸光，進而產生電子-電洞對，由於光檢測器的工作原理是工作於逆偏之下，P+接負、N+正，因此產生的電子會被直接拉到N+區，而電洞則會經過MQW結構再到達P+區，其目的是利用MQW的ΔEV＞ΔEc，期望電洞經過MQW時，可藉由較高的ΔEV獲得較高的動量，進而撞擊出更多的電子電洞對來達到較高的增益。
實驗結果顯示本結構在約-2V左右有明顯的光增益，證實此結構確實有效。
本實驗採用不同的鋁電極圖形，在偏壓為-1V時，點電極的光暗電流比為15.19倍，網狀電極的光暗電流比為52.6倍；點電極加鍍薄膜的光暗電流比為17.9倍，網電極加鍍薄膜的光暗電流比為134倍，結果顯示網狀電極較點狀電極佳；有鍍金屬薄膜又較沒鍍金屬薄膜的佳。
此外，我們在IV量測的過程中，發現到此結構在照光後有太陽能的IV特性，點電極有鍍膜的轉換效率已達8.26%

The SiGe based separate-absorption-multiplication avalanche-photodiode（SAMAPD）and has been implemented for the first time. The structure of SAMAPD, in our work, is P +-Si/MQW-(SiGe/Si)/ i-SiGe/N+-Si, in which the i-SiGe and quantum well structure of SiGe/Si are deposited by ultra-high-vacuum chemical-vapor-deposition (UHVCVD) system. In this structure，the thickness of i-Si0.8Ge0.2 layer is about 150nm and quantum structure is of Si (25 nm)/Si0.8Ge0.2( 5 nm) with five periods.
Experiment results shows that the current increases sharply at about 2 V reverse bias, we speculates that the avalanche effect occurred at this voltage. Two structures of dot and net are processed in our studies. We found that the photo-to-dark current ratio of Iphoto/Idark was 15.19 without and 17.9 with covered by Al thin film for dot electrodes at 1 V reverse bias voltage. A higher photo-to-dark current ratio was obtained for net electrodes, the Iphoto/Idark is 52.6 without covered by Al thin film; after covered by Al thin film, the Iphoto/Idark achieved a high value of 134.
In addition, the solar cell performance with this structure is measured by using a simulated solar source of 1000W/cm2 and a high conversion efficiency of 8.26% is obtained for dot electrodes with Al thin films.

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簽名頁
授權書．．．．．．．．．．．．．．．．．．．．．．．．．iii
中文摘要．．．．．．．．．．．．．．．．．．．．．．．．iv
英文摘要．．．．．．．．．．．．．．．．．．．．．．．．v
誌謝 ．．．．．．．．．．．．．．．．．．．．．．． ．．vi
目錄．．．．．．．．．．．．．．．．．．．．．．．．．．vii
圖目錄．．．．．．．．．．．．．．．．．．．．．．．．．ix
表目錄．．．．．．．．．．．．．．．．．．．．．．．．．xi

第一章 前言 ．．．．．．．．．．．．．．．．．．．．．．01
第二章 原理 ．．．．．．．．．．．．．．．．．．．．．．03
2.1 矽鍺的基本特性．．．．．．．．．．．．．．．．．．．03
2.2光檢測器原理．．．．．．．．．．．．．．．．．．．．．07
2.2.1 光的種類．．．．．．．．．．．．．．．． ．．．． 07
2.2.2 輻射轉換．．．．．．．．．．．．．．．．．．．．．07
2.2.3 光的吸收．．．．．．．．．．．．．．．．．．．．．08
2.2.4 P-N接面．．．．．．．．．．．．．．．．．．．．． 09
2.2.5 P-N與PIN感光二極體．．．．．．．．．．．．．．．．12
第三章 元件製程、光電量測與材料分析 ．．．．．．．．．．．17
3.1薄膜成長系統．．．．．．．．．．．．．．．．．．．．．17
3.2樣品清洗．．．．．．．．．．．．．．．．．．．．．．．18
3.3蒸鍍機系統(Thermal Evaporator System)．．．．．．．19
3.4傳統爐管退火系統(Conventional Furnace Annealing)．19
3.5光電量測系統．．．．．．．．．．．．．．．．．．．．．20
3.5.1電性量測(Current ─ Voltage measurement)．．．．20
3.5.2光譜響應量測(Spectral response measurement) ．．21
3.5.3響應率量測(Responsivity measurement)．．．． ．．21
第四章 實驗結果與討論．．．．．．．．．．．．．．．．．． 25
4.1歐姆電極．．．．．．．．．．．．．．．．．．．．．．．25
4.2 PL量測 ．．．．．．．．．．．．．．．．．．．．．．．28
4.3電性量測．．．．．．．．．．．．．．．．．．．．．．．29
4.4光譜響應．．．．．．．．．．．．．．．．．．．．．．．39
4.5太陽能電池之量測．．．．．．．．．．．．．．．．．．．41
第五章 結論與未來展望．．．．．．．．．．．．．．．．．．44

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