High-Voltage Drain-Extended FinFET With a High-${k}$ Dielectric Field Plate

Abstract

A drain-extended (De) FinFET (DeFinFET) with a high- ${k}$ dielectric field plate is proposed for high-voltage (HV) system-on-chip (SoC) applications at 10-nm CMOS technology nodes. Conventional DeFinFETs without the dielectric field plate and DeFinFETs with SiO2 and HfO2 field plate are investigated by varying the length ( ${L}_{\text {EXT}}$ ) and the doping concentration ( ${N}_{\text {EXT}}$ ) of the fin extension and the thickness ( ${T}_{\text {FOX}}$ ) of the dielectric field plate. The optimized device with the HfO2 field plate has a high breakdown voltage ( ${V}_{\text {BD}}$ ) of 8.56 V, a low specific ON-state resistance ( ${R}_{ \mathrm{\scriptscriptstyle ON}\_{}{\text {sp}}}$ ) of $6.40~\Omega \cdot \mu \text{m}^{{2}}$ , and a large figure of merit ( ${V}_{\text {BD}}^{{2}}/{R}_{ \mathrm{\scriptscriptstyle ON}\_{}{\text {sp}}}$ ) of 11.46 W/ $\mu \text{m}^{{2}}$ , which are greatly improved HV performance over other devices. This indicates that the HfO2 field plate can effectively address the tradeoff between ${V}_{\text {BD}}$ and ${R}_{ \mathrm{\scriptscriptstyle ON}\_{}{\text {sp}}}$ . In addition, the excellent electrical characteristics such as high ON-state current ( ${I}_{ \mathrm{\scriptscriptstyle ON}}$ ) of $3.07\times 10^{-{4}}$ A/ $\mu \text{m}$ , low OFF-state current ( ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ ) of $6.54\times 10^{-{10}}$ A/ $\mu \text{m}$ , and small subthreshold swing (SS) of 65.54 mV/decade are observed for the optimized HfO2-DeFinFET. Consequently, the proposed design with the high- ${k}$ field plate can be a pathway to realize HV DeFinFETs for SoC technology.