鈀及鉑攙雜矽接面的深層能階分析

Abstract

本論文主要是研究鈀和鉑攙雜二極體的高速切換特性,其目標是在矽二 極體中能得到較高的雜質濃度和較短 的二極體切換時間,並對鈀和鉑在矽 晶體中的深層能階作一分析. 我們利用深層能階暫態分析儀(DLTS)來研 究鈀和鉑在矽中的能階和雜質濃度. 由雜質濃度對於擴散 溫度和擴散時間的相依性研究指出,鈀和鉑濃度將隨擴散溫度的 增高和 擴散時間的增長而變大,切換時間隨擴散溫度的升高以及擴散時間的增長 而變短. 因此對於鈀和鉑而言,較高的擴散溫度和較長的擴散時間能得到 較高的雜質濃度和較短 的切換時間.但在另一方面,二極體的漏電流隨 著鈀和鉑雜質濃度的增加而變大. 由DLTS分析得知:鈀的施體 能階位於價帶之上0.52eV處,而受體能階位於傳導帶之下 0.22eV處.鉑 的施體能階位於價帶之上0.28eV處,而受體能階位於傳導帶之下0.2eV處. In this thesis, the characteristics of palladium-doped and platinum-doped silicon diodes are studied for the fabrication of the fast switching diodes. The goal of this study is to obtain higher trap concentration to reduce the switching time in diodes. Deep level transient spectroscopy(DLTS)is employed to analyze the electric deep levels and the trap concentration. The effect of the diffusion temperature and the diffustion durationn on theconcentrations of deep levels are studies.It is found that the concentration of deep levels due to Pd or Pt diffusion increases with increasing and duration.In addition, the measured switching time for Pd and Pt decreases with increasing temperature and duration.Furthermore,the leakage current of diodes is proportional to the trap concentration for both palladium and platinum. Finally,the deep energy levels are observed.For palladium,a donor level and an acceptor level are located at Ev+0.52eV and Ec-0.22eV,respectively. For platinum,a donor level and an acceptor level are located at Ev+0.28eV and Ec-0.2eV, respectively.