Abstract
Mixed aluminum‐phosphorus oxide films deposited on Ge (100) under ultrahigh vacuum conditions at low temperatures (≊200 °C) are found to yield low interface state densities near the band edges which are sufficient for observing both p‐ and n‐channel‐type inversion layers. As a glass‐promoting additive, it is speculated that phosphorus reduces bonding disorder at Ge/GeO2 interfaces.