控制降温对近空间升华法沉积CdZnTe薄膜形貌与结构的影响

Effects of cooling method on the morphology and structure of CdZnTe film deposited by close-spaced sublimation

采用场发射扫描电镜和X射线衍射技术研究了生长结束后的降温过程对以近空间升华法生长的CdZnTe薄膜形貌与结构的影响。分析了快速(炉冷,673K以上-8K/min)和慢速(-2K/min)两种降温速率下获得的CdZnTe薄膜的结构与形貌,并考察了降温中是否阻断生长源向薄膜的传质的影响。结果表明,所得到的薄膜均为闪锌矿结构,降温时薄膜的持续生长将抑制晶粒在平面内铺展而使其棱角钝化的趋势,以较慢的速率降温和降温时阻断传质均有利于提高薄膜的致密度,降低粗糙度及薄膜的织构强度。

This paper presents the study on the influences of the final cooling processes on the morphology and micro-structure of CdZnTe film deposited via close-spaced sublimation using field emission scanning electron microscopy and X-ray diffraction techniques. The influences of both the cooling speed and whether mass transfer stopped during cooling after the growth stage were studied, using fast （furnace cooling, -8K/min when T〉673K） and low （-2K/rain） cooling speeds, respectively. All the films obtained with different conditions possess zinc blende structure. Both lowering the cooling speed and stopping the mass transfer will improve the film density, decrease the roughness, and reduce the texture strength of the film. The growth during cooling suppresses the two dimensional in plane spreading of the grains that blunts their edges.