GaN growth on single-crystal diamond substrates by metalorganic chemical vapour deposition and hydride vapour deposition
GaN growth on single-crystal diamond substrates by metalorganic chemical vapour deposition and hydride vapour deposition
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DOI：
10.1016/s0040-6090(03)00906-4
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发表时间：
2003-10-22
期刊：
影响因子：
2.1
通讯作者：
Larsen, PK
中科院分区：
文献类型：
--
作者：
Hageman, PR;Schermer, JJ;Larsen, PK
在本研究中，利用两种不同的沉积技术，在(110)单晶金刚石衬底上生长了厚的六方GaN层。利用AlN成核层，采用金属-有机化学气相沉积(MOCVD)方法在(I10)单晶金刚石衬底上沉积了初始GaN层。该层由紧密堆积的GaN颗粒组成，厚度约为2.5um，且相对于衬底具有不同的取向。低温光致发光表明，由于较差的结构特性和/或杂质的高掺入，层的光学质量较差。该层被用作氢化物气相外延(HVPE)生长实验的模板。其结果是，GaN颗粒尺寸大大增加，并且该层由直径约50微米、高度超过100微米的大的六角形柱子组成，这些柱子从具有更均匀厚度的多晶背景中突出。该薄膜的光致发光光谱表明，与MOCVD沉积的薄膜相比，与激子有关的发射强度显著增加。X射线衍射分析表明，垂直于衬底的GaN晶体的主要取向从MOCVD薄膜的[001]转变为HVPE层的[112]。(C)2003爱思唯尔B.V.保留所有权利。
In this study a thick hexagonal GaN layer has been grown on a (110) single crystalline diamond substrate utilising two different deposition techniques. Using an AlN nucleation layer, metal-organic chemical vapour deposition (MOCVD) has been used to deposit an initial GaN layer on a (I 10) single crystal diamond substrate. The layer consists of closely packed GaN grains with a thickness of approximately 2.5 mum and with different orientations with respect to the substrate. Low temperature photoluminescence indicates a poor optical quality of the layer due to poor structural properties and/or a high incorporation of impurities. This layer was used as a template in a hydride vapour phase epitaxy (HVPE) growth experiment. As a result of this, the GaN grain size has increased enormously and the layer consists of large, hexagonal shaped pillars with a diameter of approximately 50 mum and a height of more than 100 mum protruding from a polycrystalline background having a more uniform thickness. PL spectra of this film show a strongly increased intensity of the exciton related emissions when compared to the MOCVD deposited film. X-Ray diffraction analyses revealed that the dominant orientation of the GaN crystallites perpendicular to the substrate changed from [001] for the thin MOCVD film to [112] for the HVPE layer. (C) 2003 Elsevier B.V. All rights reserved.