Hard mask etch stop for tall fins

A method, comprising:

• providing a substrate having a fin disposed thereon, wherein the fin has a base portion and an active portion, and wherein the active portion has a top surface and sidewall surfaces;
• blanket depositing a dielectric material over the top surface of the fin;
• polishing the dielectric material to expose the top surface of the fin;
• etching to recess the top surface of the fin to form a trench;
• blanket depositing a hard mask over the dielectric material and within the trench;
• polishing the hard mask to be planar with the surface of the dielectric material;
• etching the dielectric layer to exposing the sidewalls of the active portion of the fin;
• blanket depositing a gate material over the fin;
• etching the gate material to form a gate structure, wherein the gate structure wraps around the fin to define a channel region within the fin and source/drain regions on opposite sides of the channel region, and wherein the hard mask protects the top surface of the fin from the etching process.

A structure, comprising:

• a substrate having a fin, wherein the fin has a base portion and an active portion, and wherein the active portion has a top surface and first and second sidewall surfaces;
• isolation regions surrounding the base of the fin;
• a gate structure wrapping around the first sidewall surface, the top surface and the second sidewall surface of the fin, wherein the gate structure has gate sidewalls;
• sidewall spacers formed on the gate sidewalls;
• and
• a hard mask etch stop between the top surface of the fin and the sidewall spacer.