摘要
针对高性能碲镉汞探测器对碲锌镉衬底性能需求的不断提升,采用高温-真空退火方式对碲锌镉晶锭进行异位退火改性研究。结果发现,经过高温-真空退火处理的晶体中的第二相夹杂得到极大地改善,第二相夹杂尺寸和数量均减小,可实现大于5μm的第二相夹杂的去除,夹杂密度小于1×10^(3)cm^(-2);Zn组分分布均匀性得到明显地改善,特别是组分异常线情况的改善,退火后晶片中无圆弧状组分异常线出现;通过退火分压的调节,可实现晶体中Zn组分可调和Zn值的组分均匀分布,成分标准偏差可控制在0001~0002范围内,此参数可与定向生长的Zn值分布均匀性相媲美。但不同退火工艺对碲锌镉晶体的红外透过率存在影响,会导致长波波段红外透过率下降,不能满足长波和甚长波红外探测器对衬底的要求,通过退火技术二次改进,最终实现了25~25μm全波段红外透过率≥65,同时夹杂尺寸和密度未发生明显改变。
In response to the continuously increasing performance requirements for CdZnTe substrates by high performance mercury cadmium telluride(MCT)detectors,high temperature vacuum annealing is employed to study the ex situ annealing modification of CdZnTe ingots.The results show that the second phase inclusions in the crystals treated with high temperature vacuum annealing are significantly improved,with both the size and quantity of the inclusions being reduced,achieving the removal of second phase inclusions greater than 5μm,and the inclusion density is less than 1×10^(3)cm^(-2).The uniformity of the Zn component distribution is notably enhanced,particularly in terms of addressing compositional anomaly lines,with no arc shaped compositional anomaly lines observed in the annealed wafers.By adjusting the annealing partial pressure,the Zn component in the crystal can be adjusted,and the uniform distribution of the Zn value can be achieved,with the component standard deviation controlled within the range of 0.001~0.002,a parameter comparable to the uniformity of Zn value distribution achieved through directional growth.However,different annealing processes affect the infrared transmittance of CdZnTe crystals,leading to a decrease in the long wave infrared transmittance,which cannot meet the requirements of long wave and very long wave infrared detectors for substrates.Through secondary improvements with annealing technology,the full band infrared transmittance of 2.5~25μmis ultimately achieved to be≥65%,while no significant changes are observed in the size and density of the inclusions.
作者
范叶霞
刘江高
曹聪
李振兴
马启司
周振奇
张立超
FAN Ye-xia;LIU Jiang-gao;CAO Cong;LI Zhen-xing;MA Qi-si;ZHOU Zhen-qi;ZHANG Li-chao(The 11th Institute of CETC,Beijing 100015,China)
出处
《激光与红外》
北大核心
2025年第9期1427-1433,共7页
Laser & Infrared
关键词
碲锌镉晶锭
退火技术
异位
性能改进
cadmium zinc telluride crystal ingots
annealing technology
ex situ annealing
performance improvement
