[en] A low temperature Al₂O₃/4 monolayer amorphous Si gate stack process was demonstrated on p-type Ge wafers using atomic layer deposition and molecular beam epitaxy. Multifrequency capacitance-voltage (C-V) and current-voltage (I-V) characteristics showed excellent electrical properties of the Pt/Al₂O₃/4 ML Si/Ge metal oxide semiconductor capacitor. No kinks from 1 MHz to 4 kHz and a leakage current density of 2.6x10^-6 A/cm² at 1 V with an equivalent oxide thickness of 2.5 nm. The interface characterization using a conductance method showed that interface trap density at the near midgap was 8x10¹² eV^-1 cm^-2 and a mean capture cross section of holes was extracted to be 10^-16 cm²