Multi-function etching sacrificial layers to protect three-dimensional dummy fins in semiconductor devices

Abstract

A method of manufacturing a semiconductor device includes: forming mutually parallel three-dimensional (3D) conductive channels coated with a conformal sacrificial layer, the 3D conductive channels coated with the conformal sacrificial layer being formed on a semiconductor substrate; depositing a dielectric material to fill spaces between the 3D conductive channels coated with the conformal sacrificial layer, wherein a portion or all of the deposited dielectric material is doped with boron, lithium, or beryllium; performing chemical mechanical polishing (CMP) to remove a top portion of the deposited dielectric material and to expose tops of the 3D conductive channels; and after the CMP, removing the conformal sacrificial layer coating the 3D conductive channels by etching to form 3D dielectric features spaced apart from the 3D conductive channels and comprising the deposited dielectric material.

Dependencies are inferred from the claim text.