Oxidizing methods for making low resistance source/drain germanium contacts

A method of forming a contact for a semiconductor device comprising the steps of:

• defining an area on a face of a semiconductor substrate;
• forming an alloy layer on the defined area wherein said alloy layer comprises a first material and a second material, said alloy layer being doped with a dopant;
• diffusing at least some of said dopant from said alloy layer into said semiconductor substrate at the defined area thereby forming a doped portion of said semiconductor substrate;
• and
• segregating said alloy layer to form a first layer comprising said first material on the defined area, and a second layer comprising said second material.

A method of forming a contact for a semiconductor device comprising the steps of:

• defining an area on a face of a semiconductor substrate;
• selectively forming an alloy layer on the defined area wherein said alloy layer comprises a first material and a second material, said alloy layer being doped with an n-type dopant and a p-type dopant;
• diffusing at least some of said n-type dopant a first distance and at least some of said p-type dopant a second distance from said alloy layer into said semiconductor substrate at the defined area thereby forming a doped portion of said semiconductor substrate defining a p-n junction;
• and
• segregating said alloy layer to form a first layer comprising said first material on the defined area, and a second layer comprising said second material on said first layer.

A method of forming a contact for a semiconductor device comprising the steps of:

• defining an area on a face of a semiconductor substrate;
• forming an alloy layer comprising a silicon-germanium alloy on the defined area, said alloy layer being doped with at least one dopant;
• diffusing a portion of said at least one dopant from said alloy layer into said semiconductor substrate at said defined area thereby forming a doped portion of said semiconductor substrate;
• and
• segregating said alloy layer to form a germanium layer on said defined area and a silicon dioxide layer on said germanium layer.