甚长波红外波段富含大气湿度、CO2含量及云层结构和温度轮廓等大量信息,是大气遥感的重要组成部分。设计了一种32×32甚长波红外焦平面阵列,采用在ZnCdTe衬底上液相外延生长的As掺杂p型材料上进行B+离子注入形成光敏元,通过铟柱倒焊技术和带有改进型背景抑制结构的读出电路互联,制成截止波长达到14μm的焦平面器件。该红外焦平面器件像元面积为60μm×60μm,工作温度在50K温度下。测试结果显示:读出电路性能良好,焦平面黑体响应率达到1.35×10^7V/W,峰值探测率为2.57×10^10cmHz1/2/w,响应率非均匀性约为45%,盲元率小于12%。
Very long wave infrared (VLWIR) band is widely used for the remote atmosphere sounding applications, particularly for humidity, CO2 levels, cloud structure and temperature distribution. A 32×32 VLWIR HgCdTe focal plane array (FPA) was designed. The photosensitive component was fabricated by B+ ion implanting As-doped p-type material of liquid phase epitaxial growth on ZnCdTe substrate. The readout integrated circuit (ROIC) used a buffered direct injection (BDI) structure with an improved background suppression. The VLWIR focal plane array (FPA) was achieved by combining the HgCdTe detector with ROIC in terms of indium bump bonds, the cutoff wavelength of which was over 14 μm. The pixel occupied an area of 60 μm×60 μm. It could be operated at the temperatures of 50 K. The test results show that the peak detectivity and blackbody responsivity of PFAs are 2.57×10^10 cmHz1/2W and 1.35×107 V/W, respectively. The nonuniformity of responsivity is about 45%, and dead pixels ratio is less than 12%.