Metamorphic in_0.53Ga_0.47as metal-oxide-semiconductor structure on a gaAs substrate with zro₂ high-κ dielectrics

The electrical properties of metamorphic In_0.53Ga_0.47 As metal-oxide-semiconductor capacitors with a 100-Å-thick ZrO ₂ layer as high-κ dielectrics were investigated. The In _0.53Ga_0.47As surface was pretreated by either sulfur passivation or HCl cleaning before the ZrO₂ deposition. Owing to the lower interface-state density after sulfidation, the sulfur-passivated capacitor exhibited better accumulation capacitance and strong inversion at capacitance-voltage measurement than the HCl-cleaned capacitor after post deposition annealing at 350°C. On the basis of material analyses, the capacitors that subjected to underwent sulfur treatment were found to acquire a thin sulfur layer on the interface, which protects their surface from air exposure and prevents performance degradation.