10μm 1280×1024 HgCdTe中波红外焦平面阵列探测性能提升

Improved detection performance of 1280×1024 middle-wavelength infrared HgCdTe focal plane arrays with 10μm pixel pitch

对像元尺寸为10μm的1280×1024碲镉汞(HgCdTe)中波红外焦平面阵列的制备技术和性能进行了研究。通过B+注入制备小尺寸n-on-p平面结;采用高平整度HgCdTe外延材料和高精度的倒焊互连技术,实现高的电学连通率;采用多段温度填胶固化和边缘刻蚀工艺减轻HgCdTe器件和读出集成电路(ROICs)之间的热失配,从而降低焦平面器件失效率。在85 K焦平面工作温度下,研制探测器的光谱响应范围为3.67μm至4.88μm,有效像元率高达99.95%,并且探测器组件像元的平均噪声等效温差(NETD)和暗电流密度的平均值分别小于16 mK和2.1×10^(-8)A/cm^(2)。与像元尺寸为15μm的探测器相比,10μm的1280×1024中波红外探测器可获取更加精细的图像,具有更远的识别距离。目前,该技术已成功转移到浙江珏芯微电子有限公司(ZJM)的HgCdTe红外探测器产线。

In this paper,an investigation into the preparation technology and performance of 1280×1024 middlewavelength(MW)HgCdTe infrared focal plane arrays(IRFPAs)with a pixel size of 10μm was introduced.The manufacturing process of these high-resolution FPAs involved the utilization of B+injection to establish smallsized n-on-p junctions and the application of high-precision In-bump interconnection.Through development of the process,the adverse effects of the mismatch between HgCdTe devices and readout integrated circuits(ROICs)were mitigated,thereby reducing the likelihood of device failure.The assembled FPAs were evaluated to photoelectric performance evaluation at a temperature of 85 K.The experimental results demonstrate that the detector's spectral response encompasses a wavelength range of 3.67μm to 4.88μm.The highest pixel operability of the assembly can reach 99.95%.The average values of the noise equivalent temperature difference(NETD)and the dark current density for all the pixels of the assembly are respectively less than 16 mK and 2.1×10^(-8) A/cm^(2).In comparison with a 15μm pitch detector,the utilization of the 1280×102410μm MWIR detector facilitated the capture of finer details in target images and extended the identification range.At present,this technology has been successfully transferred to the HgCdTe FPA production line of Zhejiang Juexin Microelectronics Co.Ltd.(ZJM).The production capacity and yield are constantly increasing.