Developments in X-ray and astronomical CCD imagers

Abstract

There have been many recent developments in the attributes and capabilities of silicon-based CCD detectors for use in space and ground-based astronomy. The imagers used as X-ray detectors require very low noise and excellent quantum efficiency over the energy range of 200–10 000 eV. This is achieved using a combination of front and back-illuminated imagers fabricated on a 5000 Ω-cm resistivity material. A requirement for ground-based imagers is very good sensitivity between 350 and 1000 nm, as well as low noise and a high degree of spatial uniformity. We will describe the fabrication and performance of these imagers. Special features integrated into the CCD pixel architecture have increased the capability of the imagers. A fast electronic shutter has been developed for a wavefront sensor in an adaptive optics system. An orthogonal transfer CCD has been designed to compensate for the image motion relative to the CCD focal plane. Also, an antiblooming drain process has been developed so bright sources do not extend spatially into adjacent pixels in back- and front-illuminated imagers. Aspects of the design, fabrication, and performance of imagers with these features will be described.