Effect of H₂ on interface traps in the LPNP transistors caused by 3 MeV proton irradiations

In this paper, the effects of 3 MeV proton irradiations on gate controlled lateral PNP (GLPNP) transistors are investigated with and without molecular hydrogen (H₂) soaking. The electrical parameters are measured in-situ during irradiation. Radiation defects indicated by 3 MeV protons are measured by deep level transient spectroscopy (DLTS). At a given the irradiation fluence, the degradation for the H₂-soaked transistors is much larger than that for the non-soaked transistors. Excess base current (ΔI_B) for the H₂-soaked transistors is bigger than that for the non-soaked transistors at a given emitter-base voltage and the same irradiation fluence. According to the gate sweep (GS) curve, it can be calculated that the number of the interface traps of the H₂-soaked transistors is significantly larger than that for the non-soaked transistors under the same fluence, as demonstrated by DLTS analyses. 3 MeV protons could mainly produce the ionization damage in the GLPNP transistors, displacement damage can be almost negligible. The results for the 70 keV electron irradiations further confirm that 3 MeV protons could mainly produce ionization damage in the GLPNP transistors and hydrogen can aggravate the formation of interface traps in GLPNP transistors.