Method of making self-aligned continuity cuts in mandrel and non-mandrel metal lines

Patent metadata

Field	Value
Publication number	US-9953834-B1
Application number	US-201715723232-A
Country	US
Kind code	B1
Filing date	Oct 3, 2017
Priority date	Oct 3, 2017
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method includes providing a structure having a dielectric layer, a 1 st hardmask layer, a 2 nd hardmask layer and a 1 st mandrel layer disposed respectively thereon. A 1 st mandrel plug is disposed in the 1st mandrel layer. A 2 nd mandrel layer is disposed over the 1 st mandrel layer. The 1 st and 2 nd mandrel layers are etched to form a plurality 1st mandrels, wherein the 1 st mandrel plug extends entirely through a single 1 st mandrel. The 1 st mandrel plug is etched such that it is self-aligned with sidewalls of the single 1 st mandrel. The 1 st mandrels are utilized to form mandrel metal lines in the dielectric layer. The 1 st mandrel plug is utilized to form a self-aligned mandrel continuity cut in a single mandrel metal line formed by the single 1 st mandrel.

First claim

What is claimed is:

1. A method comprising:
providing a structure having a dielectric layer, a 1 st hardmask layer, a 2 nd hardmask layer and a 1 st mandrel layer disposed respectively thereon;
disposing a 2 nd non-mandrel opening in the 2nd hardmask layer;
disposing a 2 nd mandrel layer over the 1 st mandrel layer;
etching the 1 st and 2 nd mandrel layers to form a plurality 1st mandrels, wherein the 2 nd non-mandrel opening extends between a pair of adjacent 1 st mandrels;
forming 1 st mandrel spacers on sidewalls of the 1 st mandrels and a 2nd non-mandrel plug in the 2 nd non-mandrel opening, wherein the 2 nd non-mandrel plug is self-aligned with sidewalls of adjacent 1 st mandrel spacers; and
utilizing the 1 st mandrel spacers to form mandrel and non-mandrel metal lines within the dielectric layer; and
utilizing the 2 nd non-mandrel plug to form a self-aligned 2 nd non-mandrel continuity cut in one of the non-mandrel metal lines within the dielectric layer.

2. The method of claim 1 comprising:
disposing a 1 st mandrel plug in the 1st mandrel layer prior to disposing the 2 nd mandrel layer over the 1 st mandrel layer, the 1 st mandrel plug positioned to extend entirely through a single 1 st mandrel after the 1 st mandrels have been formed;
forming the 1 st mandrels such that they include the single 1 st mandrel;
etching the 1 st mandrel plug such that it is self-aligned with sidewalls of the single 1 st mandrel;
utilizing the 1 st mandrels to form mandrel metal lines in the dielectric layer; and
utilizing the 1 st mandrel plug to form a self-aligned Pt mandrel continuity cut in a single mandrel metal line formed by the single 1 st mandrel.

3. The method of claim 2 comprising:
removing the 1 st mandrels from the structure; and
forming a metal line pattern from the remaining 1 st mandrel spacers, Pt mandrel plug and 2 nd non-mandrel plug, wherein:
areas between the 1 st mandrel spacers that were not covered by the 1 st mandrels define non-mandrel line regions,
areas that were covered by the 1 st mandrels define mandrel line regions, and
the mandrel line regions alternate with the non-mandrel line regions within the pattern.

4. The method of claim 3 comprising etching the metal line pattern down through the 2 nd hardmask layer and into the 1 st hardmask layer to dispose the pattern over the dielectric layer.

5. The method of claim 4 comprising:
etching the metal line pattern into the dielectric layer to form a series of parallel metal line trenches therein; and
metalizing and planarizing the trenches wherein:
the metalized trenches form the mandrel and non-mandrel metal lines,
the 1 st mandrel spacers of the pattern form spacings between the metal lines,
the 1 st mandrel plug of the pattern forms the mandrel continuity cut, and
the 2 nd mandrel plug of the pattern forms the non-mandrel continuity cut.

6. The method of claim 2 comprising:
disposing a 3rd mandrel layer over the 1 st and 2 nd mandrel layers;
patterning and etching 2 nd mandrels into the 3 rd mandrel layer;
forming 2 nd mandrel spacers on sidewalls of the 2 nd mandrels;
removing the 2 nd mandrels; and
etching the 1 st and 2 nd mandrel layers selective to the 2 nd mandrel spacers to form the 1 st mandrels.

7. The method of claim 6 comprising:
the 1 st and 2 nd mandrel layers having substantially the same material compositions;
the 1 st and 3 rd mandrel layers having a substantially different material compositions;
the 1 st mandrel plug having a material composition that is substantially different from the 1 st and 3 rd mandrel layers; and
the 1 st mandrel plug, the 2 nd non-mandrel plug and the 1 st mandrel spacers having substantially the same material composition.

8. The method of claim 2 wherein the 1 st and 2 nd mandrel layers have substantially the same material composition.

9. The method of claim 8 wherein the 1 st mandrel plug and the 1 st mandrel layer have a substantially different material composition.

10. The method of claim 1 wherein the method is one of a self-aligned double patterning process and a self-aligned quadruple patterning process.

Assignees

• Globalfoundries Inc

Inventors

• Sun Lei
• Xie Ruilong
• Zhang Xunyuan
• Kim Ryan Ryoung-Han

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10P76/4083

  characterised by their behaviours during the lithography processes, e.g. soluble masks or redeposited masks · CPC title

• H10P76/405

  characterised by their composition, e.g. multilayer masks · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10W20/089 Primary

  using processes for implementing desired shapes or dispositions of the openings, e.g. double patterning · CPC title