InGaAs metal-oxide-semiconductor capacitors with HfO2 gate dielectric grown by atomic-layer deposition

Abstract

The influence of various process conditions on the structural integrity and electrical properties of $\mathrm{Al}∕\mathrm{Hf}{\mathrm{O}}_2∕p\text{-}{\mathrm{In}}_{0.13}{\mathrm{Ga}}_{0.87}\mathrm{As}$ metal-oxide-semiconductor capacitors was investigated. Room temperature capacitance voltage measurements revealed postdielectric deposition anneal reduced hysteresis by more than $0.5\mathrm{V}$ and sulfur passivation of InGaAs improved the capacitance frequency dispersion properties as well as reduced interface trap density. At $V=V_{\mathrm{FB}}-1\mathrm{V}$ , the leakage current densities $\sim 1.3\times {10}^{-7}$ , $0.4\times {10}^{-6}$ , and $1.3\times {10}^{-6}\mathrm{A}∕{\mathrm{cm}}^2$ were measured in devices with annealed $\mathrm{Hf}{\mathrm{O}}_2$ (110 and $32\mathrm{\AA }$ ) and sulfur-passivated InGaAs ($110\mathrm{\AA }$ unannealed $\mathrm{Hf}{\mathrm{O}}_2$ ), respectively. Transmission electron microscopy revealed sharp epitaxial InGaAs/crystalline $\mathrm{Hf}{\mathrm{O}}_2$ and $\mathrm{Ga}\mathrm{As}∕\mathrm{In}\mathrm{Ga}\mathrm{As}$ interfaces.