A Crystalline Oxide Passivation on In₀․₅₃Ga₀․₄₇As (100)

The passivation of In₀․₅₃Ga₀․₄₇As surfaces is highly desired for transistor performance. In this study, the feasibility of a crystalline oxide passivation on In₀․₅₃Ga₀․₄₇As (100) is demonstrated experimentally. The (3 × 1) and (3 × 2) crystalline oxide reconstructions are formed on the de-capped In₀․₅₃Ga₀․₄₇As (100) surfaces through the control of the surface oxidation states. By monitoring the evolution of chemical states and associated structures of the In₀․₅₃Ga₀․₄₇As (100) surfaces upon O₂ and subsequent atomic hydrogen exposure, we find that the control of the Ga oxide states is critical to the formation of the crystalline oxide reconstructions. The stability of the crystalline oxide layers upon the atomic layer deposition of HfO₂ is investigated as well. Furthermore, the capacitance voltage behavior of metal oxide semiconductor capacitors with an HfO₂ dielectric layer reveals that the crystalline oxide reconstructions result in a decrease in the density of interface traps (D_{it}) from ∼1 × 10¹³ cm⁻² eV⁻¹ to ∼1 × 10¹² cm⁻² eV⁻¹ compared with the de-capped surface. The crystalline oxide passivation offers a platform to develop In₀․₅₃Ga₀․₄₇As devices with a low density of interface states.