Infrared monolithic HgCdTe IR CCD focal plane technology

Charge-Coupled Devices (CCDs) fabricated directly on narrow bandgap compound semiconductors have infrared sensitivity resulting from band-to-band intrinsic carrier generation. Hg Cd Te is an ideal material for IR CCD focal planes because an excellent native oxide exists and the bandgap can be adjusted to match either the 3-5 µm or the 8-12 µm atmospheric transmission window. Results are presented on 4-phase 16-stage CCD shift registers fabricated on Hg.7Cd.3Te (5 µm cutoff) with n-type carrier concentration of ND= 1 - 2 × 10¹⁵cm^-3. Charge transfer efficiency (CTE) of up to .9995 has been obtained at 77°K at 50 kHz and Metal-Insulator-Semiconductor (MIS) diodes have shown storage times of up to 80 sec. at 77°K.