A High Performance 1200 X 400 CCD Array For Astronomy Applications

Abstract

This paper describes the design and performance of a scientific CCD array for use in astronomy applications. The device is a four-phase, buried-channel CCD structure that operates in the frame-transfer mode for imaging the scenes at low light levels in the spectral regions from 450 nm to near infrared. The sensor consists of two sections of 1200 x 200 CCD imaging elements with 27 x 27 μm pixel size. Each section can be operated independently with its own four-phase vertical clock or as a full frame 1200 x 400 imager when both sections share the same four-phase clock. The device' serial-parallel-serial structure allows the charge in the parallel (vertical) CCD shift registers to be able to shift either up or down to the top or bottom serial (horizontal) CCD readout register. The readout register, in turn, transfers the charge in sequence to the output amplifier. The high full-well capacity of each pixel (> 0.6 million electrons) and low readout noise (< 4 electrons rms) yield a dynamic range of more than 103 dB. Using the multi-pinned-phase (MPP) mode of operation, the saturation time is more than 30 seconds at room temperature. The device has an excellent charge-transfer efficiency (CTE) of more than 0.999996 at low light level and does not exhibit any charge-packet problem which has plagued other CCD manufactures. In addition to top-side illumination, the device layout also can accomodate back-side thinning and back-side illumination for improvement on short wavelength spectral response. Subject terms: astronomy; charge-coupled device (CCD); near-infared; full-well capacity; multi-pinned-phase (MPP); dynamic range.