CdZnTe晶体生长用石英管的镀碳工艺研究

Investigation of the carbon coating on quartz ampoules for CdZnTe crystal growth

使用金相显微镜、推力分析仪测试等手段研究了镀碳工艺参数对碳膜的表面形貌、碳膜和石英结合力的影响。获得了一个优化的镀碳工艺参数,即在镀碳温度为950～1100℃,气体流量为4～7ml/h,镀碳时间为6h,冷却时间为12h的条件下得到的碳膜较为均匀,而且和石英结合的较好。使用该工艺条件镀膜的石英管生长出的CdZnTe晶体表面光洁,位错密度低,约为4×104cm-2。

The carbon films coated on the inner surface of quartz ampoules in different technological conditions were tested and analyzed by microscope and thrust analytic instrument. The morphology and etching pits of crystals, which grown in these ampoules, were also observed. The effect of the technological parameters on the surface topography of carbon films and the binding force between carbon films and quartz was studied. And optimal technological parameters of carbon coating are obtained, i.e. carbon coating temperature of 950-1100°C, the gas-flow rate of 4-7 ml/h, the carbon coating time of 6 h and the cooling time of 12 h. Under the condition, the thickness of carbon films is more uniform and its binding with quartz is much stronger. Moreover the as-grown CdZnTe crystal has a smoother surface and lower dislocation density.