Methods for Wet Clean of Oxide Layers over Epitaxial Layers

A method, comprising:

• forming a silicon fin over a silicon substrate;
• forming a silicon germanium region over the silicon fin;
• forming a silicon region over the silicon germanium region;
• etching to expose a portion of the silicon germanium region;
• performing oxidation to form an silicon germanium oxide layer in a portion of the silicon germanium region;
• and
• treating the silicon germanium oxide layer with a solution including an oxidizer.

A method, comprising:

• forming an epitaxial layer over a silicon substrate;
• performing an oxidation of the epitaxial layer to form an oxide layer containing unreacted atoms from the epitaxial layer;
• treating the oxide with a solution including an oxidizer to form soluble oxide molecules with the unreacted atoms;
• and
• wet cleaning the oxide with a solution to remove the soluble oxide molecules.