Novel Ultralow On-resistance Accumulation-mode LDMOS with Integrated Diodes

A novel accumulation-mode LDMOS with ultralow specific on-resistance $(R_{\text{on},\text{sp}})$ is proposed and experimentally investigated. It features two separately integrated diodes above the N-drift, which not only forms high density electron accumulation layer in the on-state, but also assists depleting the N-drift to increase the doping centration $(N_{\mathrm{d}})$ in the off-state. Therefore, the $R_{\text{on},\text{sp}}$ of the novel device is dramatically decreased. The key fabrication process and layout are demonstrated. The fabricated prototype device shows $R_{\text{on},\text{sp}}$ of $29.3\mathrm{m}\Omega\cdot \text{cm}^{2}$ and BV of $483\mathrm{V}$ The $R_{\text{on},\text{sp}}$ is decreased by 33.7% compared with triple RESURF LDMOS at the same BV.