Etch stop for airgap protection
AssigneesInternational Business Machines Corporation, Globalfoundries Inc.
InventorsKangguo Cheng, Ruilong Xie, Tenko Yamashita
Life of this patent
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Abstract
A semiconductor device that includes a gate structure on a channel region of a semiconductor device. Source and drain regions may be present on opposing sides of the channel region. The semiconductor device may further include a composite gate sidewall spacer present on a sidewall of the gate structure. The composite gate sidewall spacer may include a first composition portion having an air gap encapsulated therein, and a second composition portion that is entirely solid and present atop the first composition portion.
Claims20
A method of forming a semiconductor device comprising:
- exposing an interior surface of sacrificial spacers;
- laterally etching the interior surface of the sacrificial spacers;
- removing at least a majority of the sacrificial spacer to provide a spacer opening having a lesser width at an upper portion than at a lower portion, wherein the lesser width corresponds to said interior surface that was laterally etched;
- and
- forming a conformal dielectric material in the spacer opening, wherein the conformal dielectric material merges in the upper portion of the spacer opening to enclose an air gap in the lower portion of the spacer opening;
- and
- forming an etch resistance cap material atop the recessed portion of the spacer dielectric material, wherein the etch resistance cap material, the conformal dielectric material and the air gap provide a composite gate sidewall spacer.
A method of forming a semiconductor device comprising:
- recessing a sacrificial gate structure relative to sacrificial spacers abutting the sacrificial gate structure to expose an interior surface of sacrificial spacers;
- laterally etching the interior surface of the sacrificial spacers;
- removing the sacrificial spacers to provide a spacer opening;
- a spacer dielectric material is conformally deposited in the spacer opening, wherein the spacer dielectric material encloses an air gap in the lower portion of the spacer opening;
- forming an etch resistance cap material atop the spacer dielectric material;
- and
- forming contacts to the semiconductor device, wherein an etch process for forming via openings for the contacts is selective to the etch resistance cap material.
A method of forming a semiconductor device comprising:
- laterally etching the interior surface of sacrificial spacers;
- removing at least a majority of the sacrificial spacer to provide a spacer opening;
- and
- forming a conformal dielectric material in the spacer opening, wherein the conformal dielectric material merges in the upper portion of the spacer opening to enclose an air gap in the lower portion of the spacer opening;
- and
- forming an etch resistance cap material atop the recessed portion of the spacer dielectric material, wherein the etch resistance cap material, the conformal dielectric material and the air gap provide a composite gate sidewall spacer.
Dependencies are inferred from the claim text.