脉冲式XeCl激光辐照a－Si∶H膜诱导晶化的研究

A STUDY OF THE XeCl PULSE LASER INDUCED CRYSTALLIZATION OF a-Si:H FILMS

当脉冲辐照ａ－Ｓｉ∶Ｈ膜的ＸｅＣｌ激光能量密度在２４０ｍＪ／ｃｍ￣２以上时，可引起被辐照膜发生明显的固相晶化；通过拉曼（Ｒａｍａｎ）散射谱、扫描电子显微照象（ＳＥＭ）和紫外（ＵＶ）分光光度吸收谱的实验，研究了不同辐照条件、不同膜厚及各种膜结构试样的晶化效果；还研究了使用ＣＯ＿２激光退火对被辐照膜的影响。结果表明，晶化膜的晶粒大小在０．１～１．０μｍ时，Ｒａｍａｎ位移为５１０ｃｍ￣（－１）～５１７ｃｍ￣（－１）、半峰高宽度为１０ｃｍ￣（－１）～１５ｃｍ￣（－１）；ａ－Ｓｉ∶Ｈ膜经ＸｅＣｌ激光辐照或ＣＯ＿２激光退火后，都会增强晶化膜的吸收效率。

The XeCl pulse laser has been used to irradiat the hydrogenated amorphous silicon(a-Si:H)film. It was shown that the irradiated films were remarkably crystallized when the energydensity of laser was over 240 mJ/cm￣2.The crystallization effect of irradiated sample of vaviousthickness,different structures, and diffenent pulse number has been researched by the Ramanscattering spectrum, scanning electron micruscope(SEM)and the ultra-violet spectrophotometer. Theannealing role of CO_2 Laser in the irradiated film was also described. The results show that the grainsizes are about0.1～1.0μm, the Raman shifts is between 510～517cm￣(-1),and the FWHM is from10cm￣(-1) to 15cm￣(-1). The absorption efficiency of crystallized film is increased in the infrared regionafter irradiated by the XeCl laser or annealed by the CO_2 Laser.