Large format backside illuminated CCD imager for space surveillance

摘要

The key features and performance data of a 2560/spl times/1960-pixel split-frame-transfer imager developed for space surveillance is described. The eight-port, backside illuminated charge coupled device (CCD) features 24 /spl mu/m pixels with buried blooming drains to provide 100% optical fill-factor and <1000/spl times/ overload protection from blooming. The imaging and storage registers are strapped with metal to achieve vertical transfer clock rates <400 KHz for the 61 mm long imaging register gates. The 5 million pixel array operates at 2.7 frames/s. The monolithic focal plane includes a 32/spl times/32-pixel frame-transfer imager, with a single output, which operates at 1000 frames/s. The output ports employ a floating diffusion output circuit with responsivity of 10.5 /spl mu/V/e and noise of 7e RMS at a 1.25 MHz clock rate. The imager is photocomposed employing a combination of 5/spl times/ and 1/spl times/ lithography. The photocomposition approach is described.