Methods of forming a semiconductor device with low-k spacers and the resulting device

摘要

One method disclosed herein includes forming at least one sacrificial sidewall spacer adjacent a sacrificial gate structure that is formed above a semiconducting substrate, removing at least a portion of the sacrificial gate structure to thereby define a gate cavity that is laterally defined by the sacrificial spacer, forming a replacement gate structure in the gate cavity, removing the sacrificial spacer to thereby define a spacer cavity adjacent the replacement gate structure, and forming a low-k spacer in the spacer cavity. A novel device disclosed herein includes a gate structure positioned above a semiconducting substrate, wherein the gate insulation layer has two upstanding portions that are substantially vertically oriented relative to an upper surface of the substrate. The device further includes a low-k sidewall spacer positioned adjacent each of the vertically oriented upstanding portions of the gate insulation layer.

主权项

1. A method, comprising:
forming a sacrificial gate structure above a semiconducting substrate; forming at least one sacrificial sidewall spacer adjacent said sacrificial gate structure; removing at least a portion of said sacrificial gate structure to thereby define a gate cavity that is laterally defined by said at least one sacrificial sidewall spacer; forming a replacement gate structure, comprising a gate insulation layer comprising a substantially horizontal portion and two substantially vertical portions that have a vertical height, wherein the two substantially vertical portions are formed so as to be positioned on the at least one sacrificial sidewall spacer in said gate cavity; after forming said replacement gate structure, forming a gate cap layer above said replacement gate structure and between said at least one sacrificial sidewall spacer; after forming said gate cap layer, removing said at least one sacrificial sidewall spacer to thereby define a spacer cavity adjacent said two substantially vertical portions of said gate insulation layer of said replacement gate structure; and forming a low-k spacer in said spacer cavity by performing a deposition process to forms a low-k material in said spacer cavity and performing a chemical mechanical polishing process to remove excess amounts of said low-k material positioned outside of said spacer cavity such that said low-k spacer in said spacer cavity is positioned horizontally adjacent to and against substantially the entire vertical height of the substantially vertical portions of the gate insulation layer of the replacement gate structure and such that an upper surface of said low-k spacer is substantially planar with an upper surface of said gate cap layer.