红外与毫米波学报, 2019, 38 (2): 02165, 网络出版: 2019-05-10
过冷度对液相外延HgCdTe薄膜厚度均匀性的影响
Influence of supercooling on the thickness uniformity of HgCdTe film grown by LPE
碲镉汞 过冷度 厚度均匀性 液相外延 cadmium mercury tellurium supercooling thickness uniformity liquid phase epitaxy (LPE)
摘要
探索了一种准确测量过冷度的实验方法, 并在此基础上, 利用光学显微镜、傅里叶红外透射光谱仪、台阶仪、白光干涉仪等测试手段分析了过冷度对HgCdTe薄膜厚度均匀性的影响.研究结果表明, 过冷度小于2 ℃, 薄膜容易出现中心凹陷、四周凸起的现象; 过冷度大于3 ℃, 薄膜中心将会明显凸起, 出现宽度为毫米级的周期性起伏, 并伴随有crosshatch线产生.当过冷度为2.5 ℃时, 薄膜厚度极差可缩小至0.5 μm, 0.5 mm×0.5 mm范围内薄膜相对于衬底的粗糙度增加量为9.07 nm.
Abstract
In this paper, a method to accurately measure the supercooling of HgCdTe films grown by LPE has been proposed. Influences of supercooling on the thickness uniformity of HgCdTe films have been studied by combining with optical Microscope, Fourier transform infrared (FTIR), step profiler and White-light Interferometer (WLI). Results show that, thickness in the center of a 20 mm×25 mm film decreases when supercooling is less than 2℃, while it increases significantly with cross-hatch pattern when supercooling is more than 3℃. Thickness variation of a 20 mm×25 mm film could be less than 0.5 μm, and the surface roughness is comparable with CZT substrate when the supercooling is around 2.5℃.
陆骏, 李东升, 吴军, 万志远, 宋林伟, 李沛, 张阳, 孔金丞. 过冷度对液相外延HgCdTe薄膜厚度均匀性的影响[J]. 红外与毫米波学报, 2019, 38(2): 02165. LU Jun, LI Dong-Sheng, WU Jun, WAN Zhi-Yuan, SONG Lin-Wei, LI Pei, ZHANG Yang, KONG Jin-Cheng. Influence of supercooling on the thickness uniformity of HgCdTe film grown by LPE[J]. Journal of Infrared and Millimeter Waves, 2019, 38(2): 02165.