Lawrence Berkeley National Laboratory

We describe improvements in CCD performance that have been achieved on 4k×4k, (15 μm)2-pixel, fully depleted CCDs for the Dark Energy Spectroscopic Instrument (DESI) [1]. With respect to our previous work on CCDs for the Dark Energy Camera and the Baryon Oscillation Spectroscopic Survey, our goals for the DESI CCD development were to improve read noise and quantum efficiency, improve the astrometric precision, and decrease pixel-size variations. We report experimental results on recently fabricated CCDs to be used in DESI.