System and method for forming a gate dielectric

A method of forming a dielectric stack on a wafer comprising:

• treating the wafer with hydrofluoric acid to form an HF-last surface;
• pre-treating the HF-last surface with ozonated deionized water for a specified time period to form a pre-treated surface;
• forming the dielectric stack on the pre-treated surface;
• and
• providing a flow of NH3 in a process zone surrounding the wafer after forming the dielectric stack, wherein forming the dielectric stack comprises:
• forming a first layer of hafnium oxide or hafnium silicate on the pre-treated surface, and
• forming a second layer of hafnium oxide or hafnium silicate on the first layer.

A method of forming a dielectric stack on a wafer comprising:

• treating the wafer with hydrofluoric acid to form an HF-last surface;
• pre-treating the HF-last surface with ozonated deionized water for a specified time period to form a pre-treated surface;
• forming the dielectric stack on the pre-treated surface wherein the dielectric stack comprises a hafnium oxide layer or a hafnium silicate layer;
• providing a flow of NH3 in a process zone surrounding the wafer after forming the dielectric stack;
• transporting the wafer to a LPCVD chamber after providing the flow of NH3;
• and
• forming a polycrystalline-Si layer or an amorphous-Si layer over the dielectric stack.