Alpha-particle-induced charge collection measurements for megabit DRAM cells

An alpha-particle-induced charge collection mechanism for megabit DRAM cells was studied using an experimental method for 1-bit cell test structures with storage areas of 1 to 30 mu m/sup 2/. The dependence of the critical charge Q/sub c/ for soft errors on the cell size and p/sup +/ barriers was extensively examined. Q/sub c/ was found to be proportional to the diagonal length of the depletion region. In addition, charge collection in the presence of p/sup +/ barriers was enhanced by charge multiplication through the weak avalanche effect.>