p型矽與矽鍺量子井遠紅外線元件之研究

Abstract

目前研發兆赫波段的波源與元件逐漸成為重要的科學研究課題，不論在化學、物理、生醫、天文遙測等方面都有廣泛的應用價值；相對於其它傳統技術製造之兆赫波源，目前以半導體技術的長足進步更提供了研發出功率高、可調性與穩定性足夠之中、遠紅外線波源的可行性；本文主要是以半導體內雜質所引起之共振態為研究主題，探討載子利用共振態所形成之分佈反轉與能階躍遷，研究以此物理機制來發展兆赫波範圍之光、電學奈米元件的可能性，研究主題分為： (一)針對p型矽受外加電場下電洞載子於基態與共振態間之能階躍遷，利 用步進掃瞄式傅立葉光譜儀之時間解析光譜量測法量測其吸收變化光譜，由光譜結果間接證明電洞被雜質共振態所捕捉的物理現象。 (二)矽鍺量子井因內應力導致價帶分離而形成之雜質共振態，利用低溫光電流的量測，研究載子經電場作用形成分佈反轉而發出兆赫波的可能性。 (三)高阻值p型矽晶圓之金屬歐姆接觸製作與電性探討。 (四)步進掃描式傅立葉光譜儀技術研究與時間解析光譜量測之探討。

Recently, developments of solid-state lasers and devices in terahertz range (10mm~1000mm) have been becoming an important scientific subject. THz radiation has a number of applications to processes in chemical, physical, outspace, and biological objects. Recent advances in semiconductor technology extended possibilities of finding high-power, tunable, and stable THz sources. The subject of this thesis is “resonant states induced by impurities in semiconductors”, studying the mechanism of intra-impurity population inversion and optical transition between resonant states and ground states of acceptor impurities in both p-type silicon and strained SiGe quantum well. The goal of this work is to develop optical and electrical nanodevices in far-infrared region. This thesis is divided into four main parts： (1)Using time-resolved step-scan spectroscopy to measure the time-dependent delta-absorbance of p-type silicon under high-electrical field. According to the spectra, we prove the holes can be captured by resonant states. (2)Studying the possibilities of THz emission from photo-current detection of strained Si0.85Ge0.15/Si quantum well at low temperature. (3)Making metal-ohmic contact on high-resistivity p-Si wafers and their I-V curves at different low temperatures. (4)Studying the technologies of step-scan Fourier Transform Spectrometer and time-resolved spectroscopy.