AlxGa1-xAs/GaAs分布布拉格反射镜的湿法氧化

对垂直腔面发射激光器(VCSEL)的AlxGa1-xAs/GaAs分布布拉格反射镜(DBR)进行了高温湿法氧化.由于AlxGa1-xAs层的氧化产生了应力而导致Al2O3/GaAs界面处出现了孔洞.这些孔洞反过来又缓解了应力而使氧化层的厚度只收缩了8%而不是理论上的20%.并且,随着氧化时间的延长,湿法氧化反应中的反应物和产物沿着多孔界面在氧化物中的传输越充分,从而使AlGaAs层的氧化进行的越完全,氧化质量就越好.

Wet Oxidation of AlxGa1-xAs/GaAs Distributed Bragg Reflectors

The wet oxidation of AlGaAs with high Al content in a distributed Bragg reflectors (DBR) is studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Some voids distribute along the oxide/GaAs interfaces due to the stress induced by the wet oxidation of the AlGaAs layers. These voids decrease the shrinkage of the Al2 O3 layers to 8 % instead of the theoretical 20 % when compared to the unoxidized AlGaAs layers. With the extension of oxidation time,the reactants are more completely transported to the front interface and the products are more completely transported out along the porous interfaces. As a result,the oxide quality is better.