Characterization of a 4Kx2K three side buttable CCD

Results are presented on the fabrication and characterization of a 4 K X 2 K three-side buttable CCD produced by Orbit Semiconductor. This first run of wafers was produced to test the ability of Orbit to produce high-quality scientific CCDs with the characteristics required for detectors to be used in optical instruments of the Keck Observatory. Also on the wafer are two 2 K X 2 K devices. Similar devices have been fabricated for us previously by Loral/Fairchild. Extensive characterization of the Loral devices has taken place over the past few years, so interest is high about the possibility that Orbit might become a second source for similar detectors. This paper presents the first results on the 4 K X 2 K CCDs, including measurements of charge transfer efficiency, low-temperature dark current, on-chip amplifier readout noise, localized charge traps, full well, and responsive quantum efficiency.