Surface pretreatment of SiGe or Ge surfaces prior to gate oxide deposition cleans the SiGe or Ge surface to provide a hydrogen terminated surface or a sulfur passivated (or S—H) surface. Atomic layer deposition (ALD) of a high-dielectric-constant oxide at a low temperature is conducted in the range of 25-200° C. to form an oxide layer. Annealing is conducted at an elevated temperature. A method for oxide deposition on a damage sensitive III-V semiconductor surface conducts in-situ cleaning of the surface with cyclic pulsing of hydrogen and TMA (trimethyl aluminum) at a low temperature in the range of 100-200° C. Atomic layer deposition (ALD) of a high-dielectric-constant oxide forms an oxide layer. Annealing is conducted at an elevated temperature. The annealing can create a silicon terminated interfaces.