Diffusion barriers for germanium

A semiconductor processing method comprising:

• forming a silicon layer on a substrate;
• exposing the silicon layer to an oxidation plasma generated from an oxidation precursor comprising O2, wherein the silicon layer is exposed to the oxidation plasma for less than or about 5 seconds, and wherein the exposure forms a silicon oxide layer on the silicon layer;
• depositing a silicon-germanium layer on the silicon oxide layer;
• and
• annealing the substrate containing the silicon-germanium layer at a temperature greater than or about 800° C.

A semiconductor structure comprising:

• a silicon-germanium layer
• a germanium barrier layer, wherein the germanium barrier layer is characterized by a thickness less than or about 20 Å;
• and
• a silicon layer, wherein the germanium barrier layer is in direct contact with the silicon layer and the silicon-germanium layer and positioned between the silicon layer and silicon-germanium layer, and wherein the silicon layer is characterized by less than or about 0.1 wt. % germanium.