Physical mechanism study of N-well doping effects on the single-event transient characteristic of PMOS

Abstract

N-well doping concentration plays an important role in singleevent transient (SET) characteristic of transistors. While adjusting the Nwell doping parameter within a proper range, it has little effect on the basic electrical performance of P-type MOSFET. The physical mechanism of well doping effects on the SET of PMOS is observed. The collapse and recovery of N-well potential, which are the critical factors that influences the SET pulse width, are analyzed by TCAD simulations. The result shows that well doping concentration could affect not only the rate of well potential recover to its equilibrium value, but the potential gradient induced by localized collapse of N-well potential between ion-strike path and source. Energy band analysis is also carried out under the triple well structure, and results show that an increase in well doping concentration will elevate the barrier of reverse-biased P-N junction and therefore cause the accumulation of holes in well, elevating the well potential, and consequently, inhibiting the parasitic bipolar amplification effect.