Method of Removing High-K Dielectric Layer on Sidewalls of Gate Structure

A method of forming a semiconductor device comprising:

• forming a replacement gate structure on a portion of a substrate, wherein source regions and drain regions are positioned on opposing sides of the replacement gate structure;
• forming an intralevel dielectric on the substrate having an upper surface that is coplanar with an upper surface of the replacement gate structure;
• removing the replacement gate structure to provide an opening to an exposed portion of the substrate, wherein sidewalls of the opening are provided by sidewalls of a remaining portion of the intralevel dielectric;
• forming a gate dielectric layer on at least the sidewalls of the opening and the exposed portion of the substrate;
• damaging a majority of the gate dielectric layer that is present on the sidewalls of the opening with an angled ion implantation, wherein a non-damaged portion of the gate dielectric layer is present at a base of the opening;
• removing the damaged portion of the gate dielectric layer selectively to the non-damaged portion of the gate dielectric layer;
• and
• forming a gate conductor of a functioning gate structure within the opening on the non-damaged portion of the gate dielectric layer.