Document Details

Document Type : Thesis 
Document Title :
EFFECTS OF DOPING CONCENTRATION ON ELECTRICAL CHARACTERISTICS OF P-TYPE BE-DOPED ALGAAS SCHOTTKY DIODES
تأثير تركيز التطعيم على الخصائص الكهربية لشتوكي دايود المصنع من مادة AlGaAs الموجبة و المطعمة بمادة Be
 
Subject : Faculty of Sciences 
Document Language : Arabic 
Abstract : P-AlGaAs Schottky barrier diodes SBDs provide a great choice for a wide variety of electronic and optoelectronic applications, due to their electrical properties which make them important components in high electron mobility transistors (HEMTs), metal-semiconductor field effect transistors (MESFETs) and other integrated circuits (ICs). However, the interface states, image force lowering, tunneling and barrier height inhomogeneity are strong factors that affect the barrier height ϕ_Bp and the ideality factor n which are the key parameters of the Schottky contacts. The effect of these factors has been discussed in the literature. These factors depend on both temperature and doping concentration and this dependence could be investigated by different electrical characterization techniques. This thesis reports the study of the current-voltage I-V characteristics of p-type Ti/Au-AlGaAs/GaAs Schottky diodes which prepared by molecular beam epitaxy growth (MBE). The barrier height ϕ_Bp and the ideality factor n have been extracted at various temperatures (100-400K) for three samples with doping concentrations ranging from 1×1016 to 1×1017 cm-3. The barrier height ϕ_Bp and the ideality factor n obtained on the basis of thermionic emission theory show an abnormal behavior, these parameters exhibit a dependence on temperature and doping concentration. ϕ_Bp increases with temperature while it decreases with the doping concentration NA. In constract, n shows the opposite behavior. That indicates the presence of tunneling current transport (thermionic field emission (TFE) and field emission (FE)) which have been confirmed from the characteristics energy E00 values. The barrier height inhomogeneity model has been applied at T=100-400K. Series resistance Rs, turn-on voltage Von, the rectification ratio IF/IR and Richardson constant A* are determined through the calculations. A* is found to be smaller by four orders of magnitude than the theoretical value. The deviation of the electrical behavior from the pure thermionic emission reveals the effect of tunneling and the barrier height inhomogeneity and hence, of doping concentration. The study is confirmed with COMSOL Multiphysics modeling and simulation program which shows better electrical properties where the ideal case is applied. 
Supervisor : Dr. Nour Ahmed Hamdan Al Ahmadi 
Thesis Type : Master Thesis 
Publishing Year : 1439 AH
2018 AD 
Co-Supervisor : Dr. Hala Abdulaziz Al-Jawhary 
Added Date : Thursday, March 15, 2018 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
فادية عبدالعزيز ابراهيمIbrahim, Fadia Abdel AzizResearcherMaster 

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