Alpha-particle-induced collected charge model in SOI-DRAM's

We have developed a model for collected charges induced by an alpha-particl e for SOI-DRAM's which assumes that the body capacitance equals the gate ca pacitance and that holes do not recombine with electrons. The validity of o ur model was supported by three-dimensional (3-D) device simulations that c onsidered various gate lengths, gate oxide thicknesses, and flatband voltag es. The work function difference between the gate and body materials caused a significant increase in the current gain. The vertical band of the body region should therefore be Bat to suppress the collected charge. A thinner gate oxide would also suppress the collected charge during a refresh interv al, This finding could not be obtained from the conventional equation.