Soft-error evaluation using proton microprobe for DRAMs

Abstract

A system for evaluation of soft-errors in Mbit DRAM was developed using 400 keV proton microprobes to reveal the correlation between an incident position of protons and susceptibility against soft-errors in a memory chip. A cell mode and a bit-line mode could be specified by incident positions of protons. Soft-errors were induced by the proton incidence within about 6 mu m around the memory cell, in particular easily induced within 4 mu m. Such regions in which soft-errors is induced by the proton incidence were found not to depend on the spot size of proton microprobes.<>