US 2010/0136792 A1 · SELF-ALIGNED MULTI-PATTERNING FOR ADVANCED CRITICAL DIMENSION CONTACTS

Abstract

Embodiments of the present invention pertain to methods of forming patterned features on a substrate having a reduced pitch in two dimensions as compared to what is possible using standard photolithography processing techniques using a single high-resolution photomask. A spacer layer is formed over a two-dimensional square grid of cores with a thickness chosen to leave a dimple at the center of four cores on the corners of a square. The spacer layer is etched back to reveal the substrate at the centers of the square. Removing the core material results in double the pattern density of the lithographically defined grid of cores. The regions of exposed substrate may be filled again with core material and the process repeated to quadruple the pattern density.

Claims18

Dependent claims

A method of forming patterned features on a substrate, the method comprising:

forming a first sacrificial structural layer of core material on the substrate;
patterning the first sacrificial structural layer to form a core at each corner of a square, wherein a side of the square is equal to a first pitch;
forming a conformal layer of spacer material over the cores and exposed substrate leaving a dimple at the center of the square;
anisotropically etching the conformal layer to expose the cores and a region of the substrate at the center of the square;
and
removing the cores.

3 more elements

A method of patterning a substrate having a first sacrificial structural layer of core material using a single high-resolution photomask, the method comprising:

depositing a layer of photoresist over the first sacrificial structural layer;
patterning the layer of photoresist by exposing the layer of photoresist to radiation through the single high-resolution photomask and developing the layer of photoresist to form a first pattern of photoresist features, wherein the first pattern comprises a two-dimensional array which repeats in each dimension with a first pitch;
transferring the first pattern into the first sacrificial structural layer to form a first two-dimensional array of cores comprising four cores at the corners of a first square with a first side length of about the first pitch;
forming a first conformal layer of spacer material over the four cores and exposed substrate leaving a first dimple at the center of the first square;
anisotropically etching the first conformal layer to expose the four cores and a region of the substrate at the center of the first square;
removing the first two-dimensional array of cores;
depositing a second sacrificial structural layer;
partially etching the second sacrificial structural layer to reveal spacer material;
etching the spacer material leaving a second two-dimensional array of cores having twice the density of the first two-dimensional array of cores, the second two-dimensional array of cores comprising four cores at the corners of a second square with a second side length of about the first pitch divided by the square root of two;
forming a second conformal layer of spacer material over the second two-dimensional array of cores and exposed substrate leaving a second dimple at the center of the second square;
anisotropically etching the second conformal layer to expose the four cores and a region of the substrate at the center of the second square;
and
removing the second two-dimensional array of cores.

10 more elements

Dependencies are inferred from the claim text.

Self-aligned multi-patterning for advanced critical dimension contacts

Life of this patent

Self-aligned multi-patterning for advanced critical dimension contacts

Life of this patent

Abstract

Claims18