利用400～1200nm波段的椭圆偏振光谱对生长在蓝宝石衬底上的非故意掺杂纤锌矿氮化镓(GaN)外延薄膜进行了研究.通过拟合实验数据获得了GaN薄膜的厚度和在可见-近红外区域的折射率色散关系,即n₂(λ)=2.26₂+330.1₂/((λ/nm)₂-265.7₂).利用这一公式研究了GaN紫外-可见波段的反射光谱,计算得到的GaN薄膜厚度,与椭偏光谱结果一致,两者偏差仅为0.68%.

Unintentionally doped wurtzite GaN grown on (0001) sapphire was studied by spectroscopic ellipsometry(SE) in the wavelength range of 400～1200nm. Both the thickness and dispersion of the refractive index of GaN, i.e. n₂(λ)=2.26₂+330.1₂/((λ/nm)₂-265.7₂), were obtained by fitting the experimental data. With this formula, the reflection spectrum of GaN in the UV-VIS range was studied and the thickness of GaN was calculated. The two values of the thickness obtained by these two different methods are in good agreement and the deviation is found to be 0.68%.