用响应和串音识别焦平面探测器相连缺陷元研究

Study on connected defective elements in focal plane array identification by response and crosstalk

采用高倍光学显微镜和焦平面探测器测试系统对焦平面探测器相连缺陷元进行了测试分析,研究了焦平面探测器相连缺陷元的成因。研究结果表明:借助高倍光学显微镜很难识别相连缺陷元;采用焦平面探测器响应测试系统进行测试时,相连缺陷元的响应电压与正常元基本相同,相连缺陷元无法被识别;采用焦平面探测器串音测试系统进行测试时,相连缺陷元之间串音为100%,明显不同于正常元,此时两元相连缺陷元响应电压是正常元响应电压的二分之一,相连缺陷元可以被有效识别。光刻腐蚀引入的台面或电极相连,以及光刻剥离引入的铟柱相连导致了缺陷元的产生;通过光刻腐蚀、剥离工艺优化,可以有效减少焦平面探测器相连缺陷元。

The connected defective elements in Focal Plane Array （FPA） were tested by optical microscopy and FPA test-bench. The reasons of forming connected defective elements in FPA were studied. Results show that it is difficult to identify connected defective elements by optical microscopy. And it is also difficult to identify connected defective elements by FPA response testing bench because the response voltage of connected defective elements is basically the same as that of normal elements. The connected defective elements can be identified effectively by FPA crosstalk testing bench because the crosstalk between connected defective elements is 100%, which is obviously different from that of the normal elements. At this point, the response voltage of connected defective elements is average of that of the normal elements. The tables with connecting or the electrodes with connecting caused by the process of photolithography and eroding result in the generation of the connected defective elements. As well as the indium bump with connecting caused by the process of photolithography and lift-off also leads to thegeneration of the connected defective elements. Fabrication process such as photolithography, eroding and lift-off was optimized to reduce connected defective elements.