碲锌镉晶体材料合成技术研究

Study of Synthesis Technology of CdZnTe Crystal

碲锌镉晶体是研制碲镉汞红外焦平面探测器所需的衬底材料。其制备技术由源材料合成、晶体生长、衬底加工和测试评价四个部分组成。对源材料合成工艺中的放热过程和合成料化学计量比的控制方法进行了研究。通过测量合成反应过程中石英坩埚的温度,计算了合成反应过程的放热速率。用可视监控系统观测了碲锌镉多晶合成反应的动态过程,揭示了影响合成反应速率的因素。在此基础上,用温度梯度法和定向凝固法技术实现了对合成反应速率和合成料化学计量比的有效控制。

Cadmium Zinc Telluride （CZT） crystal is the substrate material required for fabricating HgCdTe infrared focal plane array detectors. Its preparing technology includes four parts： poly crystal synthesis, crystal growth, substrate processing and quality evaluation. The exothermic process of raw material synthesis and the control method of material stoichiometric ratio are studied. By measuring the temperature of the quartz crucible in the synthesis process, the exothermic rate is calculated. The dynamic process of CZT synthesis reaction is observed by a video surveillance system and the factors which have influence on the synthesis reaction rate are revealed. On this basis, the reaction rate and material stoichiometric ratio are controlled effectively by using the technologies of gradient temperature and directional solidification.