US 10,872,777 B2 · Self-aligned double patterning (SADP) method

Abstract

The present disclosure relates to integrated circuit device manufacturing processes. A self-aligned double patterning method is provided. In the method, a lithography process for line cut that determines the locations of line termini is performed after forming a spacer layer alongside the mandrel and prior to stripping the mandrel. The lithographic mask for the line cut is aligned to the mandrel and the spacer layer using a mark made of the mandrel material and the spacer material. Compared to the previous approach where the line cut process is performed after the mandrel removal, in the disclosed approach, the line termini mask is made of the mandrel material and the spacer material, and is more distinguishable compared to a mark made of just the spacer material. Thereby, the methods provide robust photo alignment signal for the line cut photolithography and precise positioning of the line termini mask.

Claims20

Dependent claims

A method of forming an integrated circuit device, comprising:

forming a masking layer over a substrate;
forming a plurality of mandrels and a mandrel mark next to the plurality of mandrels over the masking layer;
forming spacers along peripheries of the mandrels and the mandrel mark including along respective sides and ends of the mandrels;
forming a protection layer to cover a first portion of the mandrels and the mandrel mark and to expose a second portion of the mandrels;
removing the exposed second portion of the mandrels and the spacers along respective sides and ends of the second portion of the mandrels;
removing the first portion of the mandrels while leaving the spacers along respective sides of the first portion of the mandrels;
and
patterning the masking layer according to the remaining spacers to form a device mask and a mask level mark over the substrate.

5 more elements

Dependencies are inferred from the claim text.

Self-aligned double patterning (SADP) method

Life of this patent

Self-aligned double patterning (SADP) method

Life of this patent

Abstract

Claims20