气相传输平衡技术制备LiGaO2薄膜

为获得与GaN薄膜晶格失配小的衬底材料,报道了利用气相传输平衡技术(VTE)在(100)-βGa2O3单晶衬底上制备高度001]取向LiGaO2薄膜的方法。经过X射线衍射分析表明得到的薄膜是由单相LiGaO2组成。利用扫描电镜(SEM)观察表面形貌,发现经气相传输平衡技术处理得到的薄膜表面形貌主要受温度的影响,表面晶粒尺寸随温度上升而增大。而X射线衍射测试表明随着温度上升,所得到的薄膜也从多晶向单晶化转变。在经过退火处理后,通过观察吸收谱发现LiGaO2薄膜中产生色心,并且色心的种类与温度有关。表明可以通过气相传输平衡技术技术,在远低于LiGaO2熔点的温度制备外延GaN用(001)LiGaO2∥(100)β-Ga2O3复合衬底。

LiGaO2 Layers Fabricated by Vapor Transport Equilibration

To get a small lattice mismatch substrate for GaN, highly ［001］ oriented LiGaO2 layers were successfully fabricated on (100) βGa2O3 single crystal substrates by vapor transport equilibration (VTE). Xray diffractions indicated that the asfabricated layers by VTE were singlephase. As revealed by scanning electron microscopy (SEM), the morphologies of the layers were influenced by the VTE temperature. It was found that the grain size of the layers enlarged with the increasing of the VTE temperature. Xray diffraction results showed that the layers changed from polycrystalline to single crystalline with the increase of VTE temperature. After annealing processing, color center was introduced into LiGaO2 layers as the absorption spectrum showed, kind of the color centers is determined by the annealing temperature. It was shown that (001) LiGaO2∥(100) βGa2O3 composite substrate for GaNbased epitaxial film could be fabricated by VTE technique at the temperature lower than the melting point of LiGaO2.