▎ 摘　　要

NOVELTY - Forming an airgap in a semiconductor structure involves forming a high-k material on a floor of a trench, where the trench is defined on a semiconductor substrate between sidewalls of a first material and a spacer material. The gate structure is formed on the high-k material where the gate structure contacts the first material along each sidewall of the trench. The first material is etched, where the etching forms an airgap adjacent the gate structure. USE - Method for forming an airgap in a semiconductor structure os used to produce high quality devices and structures. ADVANTAGE - The parasitic capacitance in the semiconductor structure may be reduced by forming an airgap between a gate structure and a spacer material. Additionally, because a material between the gate structure and the spacer material may have a low dielectric constant, relative to a high-k material disposed between the gate structure and the substrate, selective deposition of the high-k material on the floor of the trench may also provide a reduction of parasitic capacitance. These and other embodiments, along with many of their advantages and features, are described in more detail in conjunction with the below description and attached figures. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a method of forming a semiconductor structure, which involves (a) depositing a dielectric material on a floor of a trench, where the trench is defined on a silicon substrate between sidewalls of a first material and a spacer material, and (b) forming a gate structure on the dielectric material, between the sidewalls, where the gate structure is in contact with the first material at the sidewalls of the trench; and (2) a semiconductor structure, which comprises a trench defined on a silicon substrate between sidewalls comprising a spacer material, a dielectric material disposed on the silicon substrate, and a gate structure disposed on the dielectric material, where the dielectric material and the gate structure are each separated from the spacer material by an airgap. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a method of forming an airgap in a semiconductor structure. Method for forming an airgap in a semiconductor structure (400) Form a high-k material (405) Form a gate structure (410) Remove material (415) Remove oxide material (420) Form source and drain material (425) Etch the first material (430)