Interface State Density Modification and Dielectric Reliability Enhancement of ErTi } O } /Al } O } /InP Laminated Stacks

Co-sputtering-derived ErTi _{\textit{x}} O _{\textit{y}} gate dielectric films were deposited on atomic layer deposition (ALD)-derived Al _{\text{2}} O _{\text{3}} -passivated InP substrates. The interface chemistry and electrical properties of ErTi _{\textit{x}} O _{\textit{y}} /Al _{\text{2}} O _{\text{3}} /InP MOS capacitors were investigated as a function of Er/Ti X-ray photoelectron spectroscopy (XPS) measurements, and electrical tests have revealed that an atomic ratio of 3.7/5.2 of erbium to titanium can effectively modulate the interface chemistry and obtain optimized electrical properties, achieving a large dielectric constant of 26.4, a low density of leakage current of 1.8 \times 10 ^{{-}\text{5}} A/cm ^{\text{2}} , and an enhanced breakdown properties ( \textit{V}_{\text{BD}} = 6.1 V and \textit{t}_{\text{BD}} = 4950 s on Si). Furthermore, the density of interface states ( \textit{D}_{\text{it}}\text{)} has been evaluated based on the conductance method, and leakage current mechanisms are investigated in the temperature range of 77-377 K. Current results have indicated that ErTi _{\textit{x}} O _{\textit{y}} is a ternary oxide gate dielectric with superior performance, which is of great significance for the development and exploration of new gate dielectrics for CMOS devices.