Wafer-Scale Fabrication of CMOS-Compatible Trapping-Mode Infrared Imagers with Colloidal Quantum Dots
Shuo Zhang, Cheng Bi, Tianling Qin, Yanfei Liu, Jie Cao, Jiaqi Song, Yongjun Huo, Menglu Chen, Qun Hao, Xin Tang
Abstract
Silicon-based complementary metal oxide semiconductor (CMOS) devices have dominated the technological revolution in the past decades. With increasing demands in machine vision, autonomous driving, and artificial intelligence, silicon CMOS imagers, as the major optical information input devices, face great challenges in spectral sensing ranges. In this paper, we demonstrate the development of CMOS-compatible infrared colloidal quantum-dot (CQD) imagers in the broadband short-wave and mid-wave infrared ranges (SWIR and MWIR, 1.5–5 μm). A new device architecture of trapping-mode detectors is proposed, fabricated, and demonstrated with lowered darkcurrents and improved responsivity. The CMOS-compatible fabrication process is completed with two-step sequential spin-coating processes of intrinsic and doped HgTe CQDs on an 8 in. CMOS readout wafer with photoresponse non-uniformity (PRNU) down to 4%, dead pixel rate of 0%, external quantum efficiency up to 175%, and detectivity as high as 2 × 10 11 Jones for extended SWIR at 300 K and 8 × 10 10 Jones for MWIR at 80 K. Both SWIR images and MWIR thermal images are demonstrated with great potential for semiconductor inspection, chemical identification, and temperature monitoring.