Self-aligned silicide process for silicon sidewall source and drain contacts

A method of forming a semiconductor structure, comprising:

• providing a semiconductor substrate to be silicided including a sidewall source region and a sidewall drain region formed on respective sides of a gate;
• forming a metal film over the gate and the sidewall source and sidewall drain regions;
• forming a silicon film over said metal film;
• etching anisotropically and selectively said silicon film with respect to said metal film;
• reacting said metal film with said silicon film at a first temperature to form a metal-silicon alloy;
• etching unreacted portions of said metal film;
• annealing said structure at a second temperature to form a metal-Si2 alloy over regions which are non-planar with respect to said substrate;
• and
• selectively etching unreacted portions of said silicon film.

A method of forming a silicide, including:

• providing a substrate to be silicided including forming a metal-silicon mixture over predetermined regions of said substrate;
• forming a silicon film over said metal-silicon mixture;
• etching anisotropically and selectively said silicon film with respect to said metal-silicon mixture;
• reacting said metal-silicon mixture with said silicon film at a first temperature to form a metal-rich phase;
• etching any unreacted portion of the metal-silicon mixture;
• annealing said substrate at a second temperature, to form a metal-Si2 alloy over regions of said predetermined regions which are non-planar with respect to said substrate;
• and
• selectively etching unreacted portions of said silicon film.