Characteristics of thinned backside‐illuminated charge‐coupled device imagers

A linear 500×1 charge‐coupled device (CCD) surface channel imager is thinned to less than 30 μm, with the thinned back surface accumulated to reduce the surface recombination velocity. Photoresponsivity is measured to be 90 mA/W of incident wide‐band power from a 2854‐K blackbody light source. This sensitivity is a factor of 3 higher than previously reported values. Spectral responsivity reaches a peak of 90% quantum efficiency at 7000‐A wavelength, and over 50% quantum efficiency for the spectral range from 5000 to 9000 A. A 32% square wave amplitude response at the Nyquist limit is obtained at a location 150 resolution elements from the output diode. Optical imager resolution obtained by using the backside‐illuminated device is illustrated.