Finfet with long channel length structure

A method of forming a semiconductor device, the method comprising:

• forming a plurality of adjacent channel structures in a semiconductor substrate;
• depositing a conductive material over the semiconductor substrate, wherein the conductive material is deposited across each of the adjacent channel structures;
• depositing a sacrificial mask over the conductive material;
• patterning the conductive material with the sacrificial mask to form a plurality of conductive material segments, wherein the conductive material segments extend across each of the adjacent channel structures;
• depositing a first dielectric layer over the sacrificial mask;
• depositing a second dielectric layer over the sacrificial mask;
• planarizing the first and second dielectric layers such that none of the first and second dielectric layers remain over the sacrificial mask, wherein a gap in the sacrificial mask in a location corresponding with one of the source/drain regions is filled with the first dielectric layer;
• removing the sacrificial mask;
• and
• epitaxially growing a plurality of source/drain regions from the semiconductor substrate.

A semiconductor device, comprising:

• a first region and a second region;
• a first gate structure disposed in the first region, comprising a first gate length along a channel direction;
• and
• a second gate structure and a dummy gate structure disposed in the second region, the dummy gate structure adjacent to the second gate structure along the channel direction;
• wherein the second gate structure comprises a second gate length along the channel direction greater than 0.2 um;
• and
• wherein a top surface of the second gate structure is coplanar with a top surface of the dummy gate structure.