利用反射与透射光谱测量GaN外延层的光学参数  

Measurement of Optical Parameters of GaN Epitaxy Layer Using Reflective and Transmission Spectra

作　　者：杜晓晴[1,2] 

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400030 [2]重庆大学光电工程学院,重庆400030

出　　处：《光学与光电技术》2010年第1期76-79,共4页Optics & Optoelectronic Technology

基　　金：国家自然科学基金(60701013);(60871012)资助项目

摘　　要：GaN是一种理想的紫外发光和探测材料,其光学特性参数是光学器件设计的重要依据。采用紫外反射与透射光谱相结合的方法对国产GaN外延层进行光学特性测量,利用反射率与折射率之间的关系和薄膜干涉效应,建立了GaN外延层厚度、表面反射率、光谱吸收系数的光谱测量公式。测量结果表明,GaN外延层在紫外波段存在三个吸收区,其中364 nm以下波段为强吸收区,吸收系数接近10~5cm^(-1),364～375 nm为吸收过渡区,375 nm以上波段为弱吸收区;GaN表面反射率在三个吸收区的变化不大,为0.2～0.25之间。GaN is a perfect material for ultraviolet （UV） light-emitting and detection. Its optical property parameters are important referenced evidences for device design. Optical parameters of national prepared GaN epitaxy layer are characterized by using reflective and transmission spectrum measurement method. The measurement formula of thickness, surface reflectivity and spectra adsorption coefficient of GaN layer are built by use of relationship between reflectivity and refractivity and film interference effect. The measurement results show that GaN has three adsorption wavehands in UV region, in which waveband below 364 nm is strong adsorption one and adsorption coefficient can be close to 10^5 cm^-1, between 364 nm and 375 nm is transition adsorption waveband, and above 375 nm is weak adsorption waveband. Reflectivity of GaN has small variations in whole three wavebands and its value is between 0. 2 and 0. 25.

关 键 词：光学特性 紫外光谱 吸收系数 反射率 

分 类 号：O433.1[机械工程—光学工程] TN304.2[理学—光学]