RESPONSE OF A DRAM TO SINGLE-ION TRACKS OF DIFFERENT HEAVY-ION SPECIES AND STOPPING POWERS

Multiple-bit errors caused by single-ion tracks in a 256-kilobit DRAM fabricated by a bulk process have been observed for different ion species and stopping power values. The results of this work demonstrate the utility of this device for the evaluation of ion-beam uniformity and ion-beam-induced charge collection in IC devices. Our data indicate that single-ion-induced charge transport results in multiple-bit error clusters due to lateral diffusion of excess minority carriers (electrons). Charge collection is observed to occur from a depth of up to 35 µm from the surface of the device. An apparent charge loss is observed for very heavy ions with a high stopping power (Au at 350 MeV). © 1990 IEEE