Exposure activated chemically amplified directed self-assembly (DSA) for back end of line (BEOL) pattern cutting and plugging

Patent metadata

Field	Value
Publication number	US-9625815-B2
Application number	US-201314039140-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Sep 27, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

Self-aligned via and plug patterning for back end of line (BEOL) interconnects are described. In an example, a structure for directed self-assembly includes a substrate and a block co-polymer structure disposed above the substrate. The block co-polymer structure has a polystyrene (PS) component and a polymethyl methacrylate (PMMA) component. One of the PS component or the PMMA component is photosensitive.

First claim

What is claimed is:

1. A method of fabricating an interconnect structure for a semiconductor die, the method comprising:
forming a first level of alternating metal lines and dielectric lines above a substrate;
forming a block co-polymer structure above, and having a pattern directed by, the first level of alternating metal lines and dielectric lines, the block co-polymer structure comprising a polystyrene (PS) component and a polymethyl methacrylate (PMMA) component, wherein the PS component is bound to or blended with a photo acid generator (PAG) moiety and is bound to a protecting group;
exposing a portion of the PS component and a portion of the PMMA component of the block co-polymer structure to irradiation, wherein the bound protecting group reduces chain lengths in the exposed PS component during the exposing to form an irradiated PS component, but chain lengths are not reduced in the exposed PMMA component during the exposing, wherein the PAG moiety or the bound protecting group localizes the reducing of chain lengths to the PS component; and
developing the block co-polymer structure by removing the irradiated PS component but not the exposed PMMA component to provide a patterned block co-polymer structure.

2. The method of claim 1 , wherein exposing the portion of the block co-polymer structure to irradiation comprises exposing to an extreme ultra-violet (EUV) source or an e-beam source.

3. The method of claim 1 , further comprising:
subsequent to developing the block co-polymer structure to provide the patterned block co-polymer structure, using the patterned block co-polymer structure as a scaffolding to form a second level of alternating metal lines and dielectric lines above and coupled to the first level of alternating metal lines and dielectric lines.

Assignees

• Nyhus Paul A
• Han Eungnak
• Sivakumar Swaminathan
• Putna Ernisse S
• Intel Corp

Inventors

• Nyhus Paul A
• Han Eungnak
• Sivakumar Swaminathan
• Putna Ernisse S

Classifications

• H10P95/08

  Planarisation of organic insulating materials · CPC title

• H10P76/4085

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

• H10P50/71

  using masks for conductive or resistive materials · CPC title

• H10P14/61

  using masks · CPC title

• H10P14/40

  of conductive or resistive materials · CPC title