Analysis of radiation-induced leakage in MOS-SOS edge parasitic transistors using a 3-D device simulator

The role of the edge parasitic transistor in the MOS-SOS (silicon-on-sapphire) device behavior is analyzed with a new 3-D device simulator. Radiation effects on the n-MOS device leakage are simulated by adding positive charge distributions at the back interface. It is shown that the radiation-induced leakage is very sensitive to the back interface charge density, which explains the large variations observed in practice. The 3-D simulations also demonstrate that the bottom corner of the edge transistor is the region where most of the radiation-induced leakage current flows.<>