Radiation Hardened SOI LDMOS With Dual P-Type Layers Shielding Irradiation Charge Field

In this paper, a novel radiation hardened SOI LDMOS with dual P-type layers is proposed. Based on irradiation charge field modulation, two P-type layers are introduced at the surface and bottom in N-drift region for suppressing shifts of both specific on-resistance $(R_{\textrm {on,sp}})$ and breakdown voltage (BV). Irradiation charge field is shielded by the P-type layers at low drain voltage and electron behavior in the bulk is protected against the modulation, resulting in $R_{\textrm {on,sp}}$ shifting less significantly. Besides, net charge density in drift region is reduced by the P-type layers, and then surface electric field is weakened at source side, resulting in a non-monotonic shift in BV. A low net charge density with high donor doping concentration in P-N-P drift region is pursued instead of charge balance required in traditional design. Simulated optimized results show that $R_{\textrm {on,sp}}$ shifts only 11.4% at TID ${=} 300$ krad(Si).