Effect of Anodic Oxidation on the Characteristics of Lattice-Matched AlInN/GaN Heterostructures

The effect of anodic oxidation on the electronic characteristics of lattice-matched AlInN/GaN heterostructures was investigated using field-effect transistor (FET) structures with the gate areas in direct contact with the electrolytes. The gate surface of the FETs was subjected to anodic oxidation in 0.1 M KOH. The oxidized heterostructures were analyzed by electrochemical impedance spectroscopy and by modeling the characteristics of the electrolyte-gate FETs and the energy-band diagram of the heterostructures. This analysis suggested that the anodic treatment induced a bulk oxidation of the AlInN barrier. The Fermi level at the oxidized AlInN surface was shifted deep into the bandgap. The oxidation led to a reduction of the carrier mobility and to partial depletion of the channel.     

原位钝化和催化剂钝化沟道阱能带计算

把Si3N4/AlGaN界面看成新的异质结,自洽求解薛定谔方程和泊松方程,建立起原位钝化和CATCVD钝化异质结构的新能带模型.运用这一模型,研究了原位钝化和CATCVD钝化异质结沟道阱的电子气密度、能带结构和输运性能,解释了相应的实验结果.在此基础上研究了这些新钝化异质结沟道阱能带的优化设计.优化设计的钝化复合势垒沟...     

Model Development for Analyzing 2DEG Sheet Charge Density and Threshold Voltage considering Interface DOS for AlInN/GaN MOSHEMT

A model predicting the behavior of various parameters, such as 2DEG sheet charge density and threshold voltage, with the variation of barrier thickness and oxide thickness considering interface density of states is presented. The mathematical dependence of these parameters is derived in conjunction with the interface density of states. The dependence of sheet charge density with the barrier thickness and with the oxide thickness is plotted and an insight into the barrier scaling properties of AlInN based MOSHEMTs is presented. The threshold voltage is also plotted with respect to barrier thickness and oxide thickness, which reveals the possibility of the enhancement mode operation of the device at low values of the interface DOS. The results are in good agreement with the fabricated device available in the literature.     

AlInN光电薄膜的研究进展

AlInN三元合金是优良的Ⅲ-Ⅴ族氮化物半导体材料,具有优良的光学和电学性能,在光电子器件应用方面具有广阔的应用前景.详细评述了近年来AlInN薄膜材料在生长技术、晶体结构、表面形貌、热学特性、光电特性等方面的研究,为AlInN三元合金在光电方面的基础和应用研究提供了重要参考.     

The effect of AlN buffer layer on properties of AlxIn1 − xN films on glass substrates

Al_xIn_1 − xN (AlInN) films with x = 0.36 and 0.55 were grown on glass substrate by pulsed direct-current reactive sputtering. X-ray photoelectron spectroscopy depth profiles revealed that oxygen diffused from glass substrate to AlInN films at temperatures ≧ 300 °C. After applying AlN buffer layer, the crystallinity of AlInN films was markedly improved without oxygen contamination observed. The AlN-buffered AlInN films are c-axis-oriented with low full-width-at-half-maximum of 2.9°-3.5°, fine-grained, and low electron concentration, which are comparable with AlInN films grown by other high-temperature processes. AlN buffer layer is proved to be good seeding and diffusion-barrier layers for AlInN films deposited on glass substrates.     

Characterization of Mg-Doped AlInN Annealed in Nitrogen and Oxygen Ambients

Mg-doped AlInN grown by metalorganic chemical vapor deposition (MOCVD) was demonstrated using the postgrowth thermal treatment in nitrogen and oxygen ambients. High-resolution x-ray diffraction (HRXRD) measurements showed that the crystalline quality of AlInN depends on the indium content, which is attributed to the effect of the lattice mismatch between AlInN and GaN. Interestingly, the formation of rod-shaped AlInN, which possibly resulted from the oxidation process, was observed after the postgrowth thermal treatment in the oxygen ambient. Furthermore, an InGaN/GaN multiple-quantum-well (MQW) light-emitting diode (LED) with an AlInN cladding layer was also fabricated. We believe that Mg-doped AlInN, nearly lattice matched to GaN, could play an important role for the further development of lattice-matched AlInN/GaN device applications.     

半导体氮化物AlInN的光学性质

测量了AlInN薄膜(包括InN和AIN)的透射和反射光谱,结合四层透射和反射模型得到AlInN的一系列变温光学性质,包括吸收系数、能带带隙、乌尔巴赫带尾参数、折射率等等.采用一套经验公式,描述InN薄膜在本征吸收区和乌尔巴赫吸收区的吸收系数.发现带隙以下,AIN薄膜的折射率遵守Sellmeier经验公式.用基于态密度...     

Structural properties of Al-rich AlInN grown on c-plane GaN substrate by metal-organic chemical vapor deposition

The attractive prospect for AlInN/GaN-based devices for high electron mobility transistors with advanced structure relies on high-quality AlInN epilayer. In this work, we demonstrate the growth of high-quality Al-rich AlInN films deposited on c-plane GaN substrate by metal-organic chemical vapor deposition. X-ray diffraction, scanning electron microscopy, and scanning transmission electron microscopy show that the films lattice-matched with GaN can have a very smooth surface with good crystallinity and uniform distribution of Al and In in AlInN.     

AlInN/AlGaN复合势垒增强模GaN HFET

通过自洽求解薛定谔方程和泊松方程计算了势垒层挖槽过程中沟道阱能带和电子气密度的变化.研究了异质界面上极化电荷的大小和位置对沟道阱能带和能带剪裁力度的影响.发现帽层/势垒层界面上的界面阱会导致沟道电子波函数渗透到势垒层,引起能带畸变,降低电子的二维特性和输运性能.选用复合势垒并优化设计异质界面的能带带阶、极化电荷和AlN...