GaN基激光器的特性  

Characteristics of GaN based laser diode

作　　者：张立群[1] 张书明[1] 江德生[1] 朱建军[1] 赵德刚[1] 杨辉[1] 

机构地区：[1]中国科学院半导体研究所集成光电子学国家重点实验室,北京100083

出　　处：《红外与激光工程》2009年第1期41-44,共4页Infrared and Laser Engineering

基　　金：国家自然科学基金资助项目(60836003)

摘　　要：GaN基激光器具有广泛的应用。如何获得平整腔面是蓝宝石衬底上制作GaN激光器的困难之一。通过对解理面的分析和不同衬底厚度时腔面形貌的比较,发现减薄衬底可以有效降低腔面粗糙度。当外延片厚度减薄至50μm时,获得近似镜面的腔面。激光器的测量证实了腔面的改善可以降低阈值电流,增加斜率效率。利用二维光波导模型计算了脊形高度对限制因子和远场分布的影响。计算结果说明,增加脊形高度可以增加限制因子,降低远场纵横比。通过测量具有不同脊形高度的器件,证实了脊形高度增加,阈值电流降低、远场纵横比减小。GaN based laser diodes are widely used in many fields. One of the difficulties of fabricating GaN based laser diodes on sapphire substrate is facets cleaving. Based on the analysis of cleavage planes and comparison between facet images of laser diodes and different substrate thickness, it was found that the facet roughness could be reduced by thinning the substrate. Mirror like facets were obtained when the wafer was thinned with a thickness of 50 p,m. It was demonstrated by devices measurement that the reduction of facet roughness could reduce the threshold current and enhance the slope efficiency greatly. The influences of ridge height on optical confinement factor and far-filed pattern （FFP） were investigated by two-dimensional optical waveguide simulation. The simulation results indicate that increasing ridge height can increase the optical confinement factor and reduce the FFP aspect ratio. Laser diodes with different ridge heights are fabricated and the simulation results are demonstrated by devices measurement results.

关 键 词：腔面 脊形高度 阈值电流 斜率效率 

分 类 号：TN24[电子电信—物理电子学]