Improving the blue and UV response of silicon CCD detectors

Abstract

The use of charge-coupled devices (CCDs) on ground-based optical telescopes has increased markedly over the past few years, in part due to the successful development and distribution of a number of Texas Instruments thinned, three-phase 800 X 800 detectors. It is relatively straightforward to achieve low readout noise, good charge-transfer efficiency, and low dark current from these devices. It is also possible to dramatically improve the blue and UV quantum efficiency by treating the backside surface of the detector. A UV flooding technique derived from original work at JPL which boosts the response of our two TI CCDs to nearly reflection limited values in the blue and UV is discussed along with some theory concerning silicon surface charging. This technique produces a photometrically stable detector that is well suited for use with ground-based optical telescopes.

A moderate-resolution, high-throughput CCD channel for the Multiple Mirror Telescope spectrograph

“…Prior to installation on the spectrograph, the CCD is surface charged to improve its quantum efficiency, particularly in the blue. The UV-flood recipe of Leach and Lesser (1987) is used with the following modifications: (1) the CCD and dewar are at room temperature during the procedure, and (2) the dewar is flooded with medicalgrade 0 2 as opposed to dried room air during exposure to light from a Cadmium lamp. The chip responds well to this treatment, reliably delivering the quantum efficiency shown in Figure 3.…”

Long Slit CCD Observations of Active and Normal Galaxies

“…A great effort has gone into this area (Leach and Lesser 1987;lanesick et al 1987). At the beginning of this project, the quantum efficiency of the camera system dropped to zero below ~ 4300 A (Fig.…”

“…1). In the midst of the long slit galaxy observations, the quantum efficiency below 4000 A increased signific.mtly by implementing a modified UV flood procedure (Leach and Lesser 1987) (Fig. I).…”

Long slit CCD observations of active and normal galaxies

“…Ideally, it is desirable to have the intrinsic quantum efficiency of a CCD approach its theoretical limits at all wavelengths. A great effort has gone into this area (Leach and Lesser 1987;lanesick et al 1987). At the beginning of this project, the quantum efficiency of the camera system dropped to zero below ~ 4300 A (Fig.…”