CONTACT STRUCTURE EMPLOYING A SELF-ALIGNED GATE CAP

摘要

After formation of a replacement gate structure, a template dielectric layer employed to pattern the replacement gate structure is removed. After deposition of a dielectric liner, a first dielectric material layer is deposited by an anisotropic deposition and an isotropic etchback. A second dielectric material layer is deposited and planarized employing the first dielectric material portion as a stopping structure. The first dielectric material portion is removed selective to the second dielectric material layer, and is replaced with gate cap dielectric material portion including at least one dielectric material different from the materials of the dielectric material layers. A contact via hole extending to a source/drain region is formed employing the gate cap dielectric material portion as an etch stop structure. A contact via structure is spaced from the replacement gate structure at least by remaining portions of the gate cap dielectric material portion.

主权项

1. A semiconductor structure comprising:
a gate structure including a stack of a gate dielectric and a gate electrode and overlying a portion of a semiconductor material layer; a first dielectric material layer comprising a first dielectric material and overlying said semiconductor material layer; a second dielectric material layer comprising a second dielectric material that is different from said first dielectric material and overlying said first dielectric material layer and including a planar top surface; a gate cap dielectric material portion comprising at least a third dielectric material that is different from said first and second dielectric materials and overlying said gate structure and contacting sidewalls of said first dielectric material layer; and a contact via structure extending through said second and first dielectric material layers, providing electrical contact to an element in said semiconductor material layer, and contacting at least a sidewall of said gate cap dielectric material portion, wherein said gate cap dielectric material portion comprises: a third dielectric material portion comprising said third dielectric material and contacting said sidewalls of said first dielectric material layer; and a dielectric stack of a fourth dielectric material portion and a fifth dielectric material portion, wherein said dielectric stack is laterally surrounded by said third dielectric material portion.