Estimation and verification of radiation induced N/sub ot/ and N/sub it/ energy distribution using combined bipolar and MOS characterization methods in gated bipolar devices

Complementary bipolar and MOS characterization techniques, specifically the gate sweep (GS) and sub-threshold sweep (SS), are used to estimate the radiation induced oxide charge (N/sub ot/) and interface trap (N/sub it/) buildup in gated bipolar test devices. The gate sweep and sub-threshold sweep data from recent TID testing of gated lateral PNP devices suggests an asymmetric energy distribution of interface traps after ionizing radiation exposure. Charge pumping (CP) experiments were done on the test devices to estimate the energy distribution of interface traps induced by radiation. The CP results are used in this paper to confirm the analytical findings from the GS and SS techniques and solidify the use of the complementary method as a simple way of determining radiation induced interface trap distribution in gated bipolar devices.