Thinned Charge Coupled Devices with Flat Focal Planes for UV Imaging

A versatile post-fabrication process to produce thinned, flat, back-illuminated CCDs is being developed at Jet Propulsion Laboratory's Microdevices Laboratory. This technique is compatible with many ultraviolet enhancement treatments and has been demonstrated with the delta doping process. The significance of this demonstration is that thinned, robust, and flat CCDs are produced without the use of epoxies or waxes using temperatures and materials that are compatible with standard CCD fabrication and delta doping processes. In our approach, the CCD is attached by thermocompression bonding to a specially-designed silicon substrate using gold-gold diffiision bonding prior to thinning. CCDs with optically flat membranes (10-20 pm) 'were produced and the yield for this process is excellent. These flat CCDs have been successfully delta doped. We will discuss the process of producing thinned flat CCDs, their delta doping, and our results to date.