Monolithic HgCdTe charge transfer device infrared imaging arrays

This paper compares the advantages of charge-injection-device (CID) and charge-coupled-device (CCD) technologies for the development of monolithic HgCdTe infrared image sensors for the 3-5- µm-wavelength band. Both technologies perform some signal processing before signal is transferred from the HgCdTe monolith to a silicon signal-processing chip. Line multiplexing may be performed by the CID. Both time-delay-and-integration (TDI) and multiplexing (MPX) may be performed by the CCD. Both the CID and CCD utilize the same HgCdTe material and MIS fabrication technologies. Electrical and infrared response data are given for an 8 × 8 CID matrix with background-limited performance with a 4.45-µm-long-wavelength cutoff. Previous data on 8- and 16-stage CCD linear shift registers are reviewed. New data on 32-stage linear CCD devices and a 16-TDI × 4-MPX area array are presented. The 32-stage CCD has been operated as an infrared sensor with TDI enhancement of sensitivity and background-limited detectivity for a 4.5-µm-long-wavelength cutoff.