Deposition in thermal ambience can obtain better CdTe passivation layers compared with general evaporation process. HgCdTe infrared focal plane arrays are fabricated to confirm the new process works well. Contrast n+-on-p planar photodiodes are manufactured from the same HgCdTe epilayer. Some use new process while others use general process. The performance of devices using new process shows a significant improvement. The device with general passivation process has a dark current of 7.8×10^-7 A at 50 mV negative bias voltage, and the differential resistance at zero bias is 2.6×10⁵ Ω. Meanwhile, the device with new passivation process has a dark current of 1.7×10^-8 A at 50 mV negative bias voltage, and the differential resistance at zero bias is 8.0×10⁵ Ω. Moreover, this new heating process provides a better thermal stability. The performance of devices with general passivation process declines after a long time baking at 70 °C. But the performance of the devices with heating passivation process improves a little after a long time baking even at 80 °C. The results show that CdTe deposition by vacuum evaporation in a thermal ambience can make a good HgCdTe surface passivation protection.

Date Published: 15 October 2012
PDF: 6 pages
Proc. SPIE 8419, 6th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Sensing, Imaging, and Solar Energy, 84192D (15 October 2012);

Published in SPIE Proceedings Vol. 8419:
6th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Sensing, Imaging, and Solar Energy
Yadong Jiang; Zhifeng Wang; Junsheng Yu, Editor(s)