420 X420 Charge-Coupled-Device Imager And Four-Chip Hybrid Focal Plane

We have designed and fabricated a 420 X420 pixel front-illuminated CCD imager. The device was designed to be used both individually and as part of a four-chip focal plane consisting of four chips closely abutted in a 2 X 2 array, for a total resolution of 840 X 840 pixels. Particular attention has been paid to achieving low-noise operation, and noise levels of less than 20 e- at a 1.0 MHz data rate have been achieved routinely. We describe special focal plane assembly techniques with which we have achieved 1 um relative positional accuracy between the chips.