Embodiments provided herein describe methods and systems for forming gate dielectrics for field effect transistors. A substrate including a germanium channel and a germanium oxide layer on a surface of the germanium channel is provided. A metallic layer is deposited on the germanium oxide layer. The metallic layer may be nanocrystalline or amorphous. The deposition of the metallic layer causes the germanium oxide layer to be reduced such that a metal oxide layer is formed adjacent to the germanium channel.