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Thick Epitaxy of AlN and AlGaN with controlling source molecules and nano-crystal field.

控制源分子和纳米晶场的 AlN 和 AlGaN 厚外延。

基本信息

批准号：
15360004
负责人：
KOUKITU Akinori
金额：
$ 9.98万
依托单位：
National University Corporation Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

Since AlN and AlGaN have lattice constants close to that of GaN, high thermal conductivity and wide band gap, AlN and AlGaN have been identified as a promising substrate material for the fabrication of high-power electronic devices and ultraviolet(UV) optoelectronic devices. A promising growth system is a Hydride Vapor Phase Epitaxy(HVPE), which delivers a high growth rate. However, investigations concerning HVPE of AlN have been limited, because AlCl used as a source molecule of Al reacts with quarts(SiO_2).By the thermodynamic analysis and the experiment in the investigation, it was found that AlCl_3 doesn't react with SiO_2 and HVPE of AlN is possible using AlCl_3 and NH_3 as source gases. Then, we tried to grow AlN layer by HVPE system. Successful AlN HVPE on sapphire substrates was shown. Aθ-2θ mode X-ray diffraction(XRD) profile of the layer (2.1μm thickness) grown with input partial pressures of HCl and NH_3 of 6.0 x 10^<-3> atm and 4.0x10^<-2> atm, respectively. In addition, aside from the peaks due to the sapphire substrate, only the diffraction peaks related to c-axis-oriented hexagonal AlN was onserbed.Next, we investigated a thermodynamic analysis a possibility of HVPE growth of AlGaN ternary alloys. In HVPE system for AlGaN alloy, the source molecules are AlCl_3,GaCl and NH_3. A thermodynamic analysis of HVP) of AlGaN using AiCl_3 and GaCl as group III precursors is described. For a range of values on the input ratio, temperature, and the partial pressure of hydrogen in the carrier gas, we calculated the equilibrium partial pressures and the driving force for AlN and GaN deposition in AlGaN. As a result, we showed that controllable AlGaN HVPE is possible under a low partial pressure of hydrogen (<10% hydrogen in carrier gas).

由于AlN和AlGaN具有接近GaN的晶格常数、高热导率和宽带隙，AlN和AlGaN已被认为是用于制造高功率电子器件和紫外（UV）光电器件的有前途的衬底材料。氢化物气相外延 (HVPE) 是一种很有前景的生长系统，它具有高生长速率。然而，由于AlCl作为Al的源分子会与石英(SiO_2)发生反应，因此有关AlN的HVPE的研究受到限制。通过热力学分析和研究中的实验发现，AlCl_3不与SiO_2反应，并且使用AlCl_3和NH_3作为源气体可以实现AlN的HVPE。然后，我们尝试通过HVPE系统生长AlN层。蓝宝石基板上的 AlN HVPE 已取得成功。 HCl和NH_3输入分压分别为6.0×10^-3atm和4.0x10^-2atm时生长的层(2.1μm厚)的Aθ-2θ模式X射线衍射(XRD)轮廓。此外，除了蓝宝石衬底的衍射峰外，仅观察到与c轴取向的六方AlN相关的衍射峰。接下来，我们研究了AlGaN三元合金HVPE生长的可能性的热力学分析。在AlGaN合金的HVPE体系中，源分子为AlCl_3、GaCl和NH_3。描述了使用 AlCl_3 和 GaCl 作为 III 族前驱体对 AlGaN 的 HVP 进行热力学分析。对于输入比、温度和载气中氢分压的一系列值，我们计算了 AlGaN 中 AlN 和 GaN 沉积的平衡分压和驱动力。结果表明，在低氢分压（载气中氢气<10%）下，可控 AlGaN HVPE 是可能的。