Evaluation of the Proton Induced Bulk Damage in SDRAM Utilizing 90 nm Process Technology

We describe proton induced bulk damage observed in 90 nm process SDRAM. The degradation of the data retention ability was evaluated. The effect due to the difference of process technology and memory cell structure was discussed. The result indicates that the value of the capacitance of the storage capacitor and the volume of the depletion region are key parameters concerning the failures caused by bulk damage.