金屬/ 負一菱化鎵接觸系統

Abstract

This thesis is to study the electrical properties and the mechanism of metal/nGap contacts. Some topics related to metal/nGap contacts are discussed. It made the following contributions: (1) The specific contact resistance for metal/nGap barriers were theorectically computed, based on the generalized majority carrier transport theory. Au/nGap and Ni/nGap barriers were used to experimentally verify the computed results. The obtained agreement between computation and experiment confirmed the computation results as well as the generalized majority carrier transport theory. (2) The Ni/Au-Ge/nGap contact system was studied. The specific contact resistance of Ni/Au-Ge/nGap Schottky diodes, asdeposited and heat-treated, were measured at various temperatures. The derived barrier heights, based on the computed results, were found to increase as diode were heat-treated up to 360℃ and drop abruptly as diodes were heat-treated above 360℃. (3) The barrierlowering effect between Au-Ge (12%)/nGap and Au/nGap was studied. It was found that this barrier height lowering was not caused by the metal work function difference between Au-Ge(12%) and Au. It was believed that it was due to Ge existence in the Au-Ge/nGap interface. A simple model was proposed to explained the experimentally measured barrier hight lowering form both C-V and I-V characteristics of Au-Ge/nGap contacts. (4) A systematic study on metal/nGap Schottky barrier heights was made. The barriers studied included Pt/nGap, Au/nGap, Ni/nGap, Mo/nGap, Cr/nGap, Al/nGap, Ag/nGap and Cu/nGap. The obtained barrier height values for Au, Cr, and Cu metals agreed with the existing data. The measured barrier heights on Ni, Mo and Ag extended the present barrier height data for n-type Gap. /////// 本論文為研究金屬╱負一磷化鎵接觸體之電氣特性及動作原理．討論一些有關金屬╱ 負磷化鎵接觸體之項目．本論文具有下列之供獻：（一）依據一般化主要子傳輪理論 ，對金屬╱負磷化鎵之特比接觸電阻，作理論的計算，並且用金╱負磷化鎵與鎳╱負 一磷化鎵能障作實驗來證明計算結果．所得實驗結果與計算結果相符合，如此可證實 計算之結果與一般化主要子傳輪理論．（二）對鎳╱金一鍺╱負一磷化鎵接觸系統之 研究．對鎳╱金一鍺．負一磷化鎵蕭基二極體的特比接觸電阻，作各種不同溫度的測 量，包括剛鍍完和經熱處理後之蕭基二極體．於此發現，依據上述計算結果，當熱處 理溫度漸漸升至 360℃時，所測得能障高度漸漸上升，而當熱處理溫度超過 360℃時 ，能障高度快速下降．（三）對金一鍺（12％）╱負一磷化鎵與金╱負一磷化鎵間能 障下降之研究．於此發現能障高度之下降並非由於金與金一鍺（12％）間之金屬工作 函數的差別．相信這是由於鍺存在於金一鍺╱負一磷化鎵之介面．因此提出一個簡單 的模式來解釋此種由電流一電壓測得之金一鍺╱負一磷化鎵接觸體之能障下降．（四 ）對金屬╱負一磷化鎵蕭基體之能障高度作系統之研究．這些能障包括鉑╱負一磷化 鎵、金╱負一磷化鎵、鎳╱負一磷化鎵、鉬╱負一磷化鎵、鉻╱負一磷化鎵、鋁╱負 一磷化鎵、銀╱負磷化鎵和銅╱負一磷化鎵．所得到之能障高度，對金、鉻、銅等金 屬與現有資料之值相符合，對鎳、鉬、銀等金屬增加了現有資料．