Because of the excellent initial response of the CA108A differential amplifier to radiation, it was thought that this device could be made even more radiation-resistant by use of ultra-clean processing. Several groups of amplifiers were characterized, and a baseline was drawn for further work on process variations. A test cell was designed to aid in process control. A group of wafers was split into four lots with one stabilizing processing step changed to pinpoint which step is the most important. Present data indicates the devices are stable even with process changes. The conclusion is that ultraclean processing may further stabilize and improve the radiation hardness of the CA108A amplifier.