Characterization and Control of GaN-based semiconductor interfaces for Fabrication of Field Effect Transistors

用于制造场效应晶体管的 GaN 基半导体界面的表征和控制

基本信息

批准号：
12650320
负责人：
SAWADA Takayuki
金额：
$ 2.3万
依托单位：
Hokkaido Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650320/
关键词：
GaN Schottky Diode MIS Diode AlGaN GaN Heterostructure I-V-T characteristics Schottky Barrier Height Interface State Density Surface Fermi Level 陽極エッチング界面特性電流-電圧特性

项目摘要

Interface properties of metal/GaN, insulator/GaN, and AlGaN/GaN heterostructure have been characterized for the fabrication of MESFET and HEMT devices.1. Characterization of metal/GaN interfaces ; (1) Measured I-V-T and C-V-T characteristics for various metal/n, p-GaN schottky diodes, which include the Richardson plots together with temperature dependences of the effective schottky barrier height (SBH) and the ideality factor, can be consistently explained by the previously proposed "surface patch" model. Only the fraction of the total patchy area of 10^<-5>effectively reduces the SBH at RT, while it does not affect the flat-band SBH deduced from the C-V curve. (2) The true SBHs determined from high-temperature I-V curve are weakly dependent on the metal work function with small S-values of 0.28 for n-and p-GaN samples, respectively. (3) Although the effective SBH for a metal/n-AlGaN sample is considerably lowered at RT, owing to a tunneling current, the true SBH is fairly larger as compared with that for corresponding metal/GaN sample.2. Control of Metal/GaN Interface ; I-V characteristics are greatly improved by an annealing in nitrogen. Thermal oxidation of GaN surface leads to increase of the SBH without noticeable degradation of the diode characteristics.3. Simulation of GaN growth ; A Monte Carlo simulation program for MBE-GaN growth, which incorporates formation of anti-site defect of layer, was developed, and the influence of growth conditions on the flatness of the growth front surface and on defect density was examined.4. Characterization of deep levels ; Capture cross-sections and activation energies for bulk traps and interface states at SiO_2/GaN were determined by C-t measurements.5. Characterization of AlGaN/GaN heterostructures ; (1) Electrical properties of AlGaN/GaN heterostructures were systematically revealed by I-V-T and C-V-T measurements. (2) A new anodic etching process has been developed for the fabrication of HEMT devices.

金属/GaN、绝缘体/GaN 和 AlGaN/GaN 异质结构的界面特性已针对 MESFET 和 HEMT 器件的制造进行了表征。1．金属/GaN 界面的表征； (1) 测量的各种金属/n、p-GaN 肖特基二极管的 I-V-T 和 C-V-T 特性，包括理查森图以及有效肖特基势垒高度 (SBH) 和理想因子的温度依赖性，可以通过之前的一致解释提出了“表面补丁”模型。只有总斑块面积的10 ^ -5 部分有效地降低了RT时的SBH，同时它不影响从C-V曲线推导出的平带SBH。 (2) 从高温 I-V 曲线确定的真实 SBH 与金属功函数的关系较弱，n-GaN 和 p-GaN 样品的 S 值分别较小，为 0.28。 (3) 尽管金属/n-AlGaN 样品的有效SBH 在RT 下显着降低，但由于隧道电流，真实SBH 与相应的金属/GaN 样品相比相当大。2．金属/GaN界面的控制；通过氮气退火可大大改善 I-V 特性。 GaN表面的热氧化导致SBH增加，而二极管特性没有明显下降。3． GaN生长模拟；开发了包含层反位缺陷形成的MBE-GaN生长蒙特卡罗模拟程序，考察了生长条件对生长前表面平整度和缺陷密度的影响。 4．深层表征；通过C-t测量确定了SiO_2/GaN体陷阱和界面态的捕获截面和活化能。 5． AlGaN/GaN 异质结构的表征； (1) 通过 I-V-T 和 C-V-T 测量系统地揭示了 AlGaN/GaN 异质结构的电学特性。 (2) 开发了一种新的阳极刻蚀工艺用于制造 HEMT 器件。