P-type buried layer DTSCR with predicted improved overshoot performance and discharge ability for ESD protections of advanced nanotechnology.

A novel P-type Buried Layer Diode-Triggered Silicon-Controlled Rectifier (PBL-DTSCR) with predicted good performance in electrostatic discharge (ESD) protection is proposed in this work. With P-type ESD implantations and silicide blocking layers applied to this novel structure, the efficiency of the diode triggering path is greatly improved, thus enhancing the discharge efficiency of the main path. Moreover, the parasitic SCR path is minimized by replacing the PNPN structure in conventional DTSCR to PNPNPN structure in PBL-DTSCR. This helps PBL-DTSCR to achieve a great improvement in both overshoot voltage and discharge ability. Moreover, reduced leakage current and flexible design window is also obtained by PBL-DTSCR. By optimizing the layout of PBL-DTSCR, a low trigger voltage (2.11V) and relatively high holding voltage (2.08V) is obtained, more importantly, overshoot voltage was suppressed by 40.22% (from 10.94V to 6.54V) and discharge ability was increased by 1.75 times (from 1.06A to1.86A) compared to conventional DTSCR. The leakage current of PBL-DTSCR was reduced by 99.7% (from 69.47nA to 0.1497nA) with same diode numbers compared to conventional DTSCR.