基于椭圆偏振测量技术的氮化物半导体材料光学特性研究
发布时间：2018-09-06 08:09
【摘要】：近年来,氮化镓(GaN)和相关材料已经实现了许多应用,例如发光二极管(LED)、蓝光/紫外光半导体激光器、大功率电子器件和太阳能电池等。GaN是优异的压电材料,其表现出小的残余应力,可以优化光电器件的物理特性和器件性能。铟镓氮(InGaN)是直接带隙材料,其禁带宽度从0.7 eV(InN)到3.4 eV(GaN)连续可调,涵盖从红外(IR)到紫外(UV)的宽光谱范围,这使其适用于全光谱的光电器件领域。高质量高In组分InGaN薄膜的发展已经引起了人们的重视和努力。类似地,氮化镓铝(AlGaN)合金由于其导热性高,介电常数高和带隙连续可调,在高温、大功率和深紫外光电子器件的开发中具有非常意义的研究价值。本文针对氮化物半导体材料的光学特性,利用椭偏测量技术对GaN,InGaN和AlGaN的光学常数进行了分析研究。本论文的主要内容如下:(1)对金属有机化学气相沉积法(MOCVD)在c面蓝宝石基底上生长的硅掺杂的n型GaN薄膜样品进行室温下多角度的椭圆偏振光谱的测试,并采用 Gaussian、Psemi-Mo 和 Psemi-Tri 振子模型在 193 nm-1650 nm 范围内模拟描述GaN薄膜和GaN缓冲层。经过对椭偏数据进行处理分析,可以高效的得到实验样品可靠的光学常数,为研究材料的能带结构提供了一个新的思路。(2)对高压化学气相沉积法(HPCVD)生长的含有不同In组分的InxGa1-xN薄膜样品进行多角度变温椭偏光谱测量实验,测试温度范围为室温至500℃。使用Tauch-Lorentz振子模型描述InxGa1-xN薄膜的光学常数。随In分量的增加InxGa1-xN光学常数出现和测试温度的增加时相同的趋势。(3)采用高精度的椭圆偏振测量技术研究了 A1组分变化和温度变化(300 K-823 K)对AlxGa1-N外延层的光学性能的影响。随着温度的升高,透明区域的折射率增加,所有研究样品的光学带隙值都降低。
[Abstract]:In recent years, gallium nitride (GaN) and related materials have achieved many applications, such as (LED), blue / ultraviolet semiconductor lasers, high-power electronic devices and solar cells. It shows small residual stress and can optimize the physical characteristics and device performance of optoelectronic devices. Indium gallium nitrogen (InGaN) is a direct bandgap material, whose band gap is continuously adjustable from 0.7 eV (InN) to 3.4 eV (GaN), covering a wide spectrum range from infrared (IR) to ultraviolet (UV), which makes it suitable for the field of optoelectronic devices with full spectrum. The development of high quality and high In component InGaN thin films has attracted people's attention and efforts. Similarly, because of its high thermal conductivity, high dielectric constant and continuous tunable band gap, Gallium AlN (AlGaN) alloy is of great significance in the development of high temperature, high power and deep ultraviolet photoelectronic devices. In this paper, the optical constants of GaN,InGaN and AlGaN are studied by ellipsometry according to the optical properties of nitride semiconductor materials. The main contents of this thesis are as follows: (1) the silicon doped n-type GaN films grown on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD) were measured at room temperature by multi-angle elliptical polarization spectroscopy. Gaussian,Psemi-Mo and Psemi-Tri oscillator models were used to simulate and describe the GaN film and GaN buffer layer in the range of 193 nm-1650 nm. After processing and analyzing the ellipsometry data, the reliable optical constants of the experimental samples can be obtained efficiently. A new idea is provided for the study of the energy band structure of the materials. (2) the multiangle thermo-ellipsometry of InxGa1-xN thin films with different In components grown by high pressure chemical vapor deposition (HPCVD) method is carried out. The measured temperature ranges from room temperature to 500 鈩，
本文编号：2225746
[Abstract]:In recent years, gallium nitride (GaN) and related materials have achieved many applications, such as (LED), blue / ultraviolet semiconductor lasers, high-power electronic devices and solar cells. It shows small residual stress and can optimize the physical characteristics and device performance of optoelectronic devices. Indium gallium nitrogen (InGaN) is a direct bandgap material, whose band gap is continuously adjustable from 0.7 eV (InN) to 3.4 eV (GaN), covering a wide spectrum range from infrared (IR) to ultraviolet (UV), which makes it suitable for the field of optoelectronic devices with full spectrum. The development of high quality and high In component InGaN thin films has attracted people's attention and efforts. Similarly, because of its high thermal conductivity, high dielectric constant and continuous tunable band gap, Gallium AlN (AlGaN) alloy is of great significance in the development of high temperature, high power and deep ultraviolet photoelectronic devices. In this paper, the optical constants of GaN,InGaN and AlGaN are studied by ellipsometry according to the optical properties of nitride semiconductor materials. The main contents of this thesis are as follows: (1) the silicon doped n-type GaN films grown on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD) were measured at room temperature by multi-angle elliptical polarization spectroscopy. Gaussian,Psemi-Mo and Psemi-Tri oscillator models were used to simulate and describe the GaN film and GaN buffer layer in the range of 193 nm-1650 nm. After processing and analyzing the ellipsometry data, the reliable optical constants of the experimental samples can be obtained efficiently. A new idea is provided for the study of the energy band structure of the materials. (2) the multiangle thermo-ellipsometry of InxGa1-xN thin films with different In components grown by high pressure chemical vapor deposition (HPCVD) method is carried out. The measured temperature ranges from room temperature to 500 鈩，
本文编号：2225746
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