Infrared sensing charge imaging matrix

Two-dimensional arrays of a new and novel infrared detector, the Charge Imaging Matrix, (CIM), based on HgCdTe charge transfer devices have been demonstrated on p-type HgCdTe of 0.13 eV and 0.25 eV bandgap at 78K. The purpose was to demonstrate a detector for scanned infrared focal plane applications. A principle feature of a CIM is that it can be operated at high readout rates with off-chip TDI (time-delay-integration) using silicon circuitry thus avoiding the excessive well capacity requirements of CCDs at long wavelengths. A CIM pixel has three principle elements: (1) a MIS detector with semitransparent metal gate for infrared detection separated from (2) a sense diode by (3) an opaque MIS transfer gate for charge transfer control. N-channel CIM devices with 4-5 µm and 9-10 µm cutoff wavelengths were fabricated and tested at 78K for operability, spectral response, inter-pixel cross-talk, and detectivity. Their design, operation, fabrication, and electro-optical tests will be discussed.