Mg掺杂的AlGaN的MOCVD生长

Study on Mg-doped AlGaN Films Grown by Metal Organic Chemical Vapor Deposition

文章主要研究利用金属有机物化学汽相沉积(MOCVD)方法制备的Mg掺杂A lGaN薄膜。根据Raman光谱对Mg掺杂A lGaN薄膜应力和X射线摇摆曲线对晶体质量的研究表明引入高温A lN插入层能有效调节应力,并提高薄膜质量,降低位错密度。实验发现在保持Mg掺杂量不变的情况下,随着A l组分的上升,材料中出现大量岛状晶核,粗糙度变大,晶体质量下降,由三维生长向二维生长的转变更加困难。同时研究发现A l组分的上升和Mg掺杂量的增加都会使得螺位错密度上升;Mg的掺杂对于刃位错有显著影响,而A l组分的上升对刃位错无明显影响。经过退火温度对空穴浓度影响的研究,发现对于P型A l0.1Ga0.9N样品,900℃为比较理想的退火温度。

The growth of Mg doped AlGaN films grown by metal organic chemical vapor deposition is investigated. Through studying the effect of high temperature AlN interlayer, high temperature AIN can effectively adjust the strain of the films and significantly improve the quality of films, reducing the density of dislocation. With the increase of Al composition, a large number of island-shaped crystal nuclei arise and the quality of films dramatically decreases. Three-dimensional growth mode is difficult to be transformed into two-dimensional one. Both the increase of the fraction of Al and Cp2 Mg flux can increase the density of screw dislocations. The increase of Cp2 Mg flux can dramatically increase the density of edge dislocation, while the fraction of Al has little impact on the density of edge dislocation. Finally, the influence of annealing temperature on the hole concentration of Mg doped Al0.1Ga0.gN sample is studied, finding that 900℃ is the ideal temperature to obtain the P-typed AlGaN.