US 9,431,219 B1Granted

Method for making guiding lines with oxidized sidewalls for use in directed self-assembly (DSA) of block copolymers

AssigneeHGST Netherlands B.V.

InventorsJulia Cushen, Ricardo Ruiz, Lei Wan

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method that uses both electron beam (e-beam) lithography and directed self-assembly (DSA) of block copolymers (BCPs) makes guiding lines with oxidized sidewalls for use in subsequent DSA of BCPs. A series of films is deposited on a substrate including a first cross-linked polymer mat layer, a layer of resist, an etch stop layer resistant to oxygen reactive-ion-etching, a second cross-linked polymer mat layer, and an e-beam resist. After patterning and etching the second mat layer, a BCP self-assembles onto the patterned second mat layer and one of the BCP components is removed. Then the second mat layer is etched, using the remaining BCP component as an etch mask. Additional etching steps then create guiding lines of the first mat layer with oxidized sidewalls. The resulting guiding lines have better quality and lower roughness than guiding lines made with just e-beam lithography.

Claims20

Dependent claims

A method for making guiding lines on a substrate for directed self-assembly (DSA) of a block copolymer (BCP) having a natural pitch L0 comprising:

providing a substrate;
forming a first cross-linked polymer mat layer on the substrate;
depositing a first layer of resist on the first mat layer;
depositing an etch stop layer resistant to oxygen reactive-ion-etching on the resist layer;
forming a second cross-linked polymer mat layer on the etch stop layer;
depositing a second layer of resist on the second mat layer;
patterning the second layer of resist on the second mat layer into a plurality of spaced second resist stripes having a width substantially equal to nL0 and a pitch substantially equal to (n+k)L0, where n and k are integers equal to or greater than 1;
reactive-ion-etching the exposed second mat layer in an oxygen gas to remove the second resist and oxidize the exposed second mat layer, leaving a plurality of alternating second mat stripes and oxidized second mat stripes;
depositing a BCP comprising first and second BCP components on the second mat stripes and oxidized second mat stripes;
annealing said deposited BCP to cause the BCP to self-assemble into said first and second components on the second mat stripes and oxidized second mat stripes;
after the BCP has self-assembled, removing the BCP component on the second mat stripes;
etching the second mat layer, using the BCP component on the oxidized second mat stripes as an etch mask to expose the underlying etch stop layer;
reactive-ion-etching the exposed etch stop layer, leaving stripes of etch stop layer on the resist layer;
reactive-ion-etching the exposed resist layer and underlying first mat layer in an oxygen gas, using the stripes of etch stop layer as an etch mask, leaving stripes of first mat layer as guiding stripes with oxidized sidewalls, the guiding stripes having a width substantially equal to nL0 and a pitch substantially equal to (n+k)L0, where n and k are integers equal to or greater than 1;
and
removing the remaining resist layer and etch stop layer.

13 more elements

A method for making guiding lines on a substrate for directed self-assembly (DSA) of a block copolymer (BCP) having a natural pitch L0, the substrate comprising a substrate base and a hard mask layer comprising diamond-like carbon (DLC) on the substrate base, the method comprising:

forming a first cross-linked polymer mat layer on the hard mask layer;
depositing a layer of resist on the first mat layer;
depositing a silicon-containing etch stop layer resistant to oxygen reactive-ion-etching on the resist layer;
forming a second cross-linked polymer mat layer on the etch stop layer;
depositing a layer of electron-beam (e-beam) resist on the second mat layer;
patterning with e-beam the e-beam resist on the second mat layer into a plurality of spaced e-beam resist stripes having a width substantially equal to nL0 and a pitch substantially equal to (n+k)L0, where n and k are integers equal to or greater than 1;
reactive-ion-etching the exposed second mat layer in an oxygen gas to remove the e-beam resist and oxidize the exposed second mat layer, leaving a plurality of alternating second mat stripes and oxidized second mat stripes;
depositing a BCP comprising first and second BCP components on the second mat stripes and oxidized second mat stripes;
annealing said deposited BCP to cause the BCP to self-assemble into said first and second components on the second mat stripes and oxidized second mat stripes;
after the BCP has self-assembled, removing the BCP component on the second mat stripes;
etching the second mat layer, using the BCP component on the oxidized second mat stripes as an etch mask to expose the underlying silicon-containing etch stop layer;
reactive-ion-etching the exposed silicon-containing etch stop layer, leaving stripes of silicon-containing etch stop layer on the resist layer;
reactive-ion-etching the exposed resist layer and underlying first mat layer in an oxygen gas, using the stripes of silicon-containing etch stop layer as an etch mask, leaving stripes of first mat layer mat as guiding stripes with oxidized sidewalls on the hard mask layer, the guiding stripes having a width substantially equal to nL0 and a pitch substantially equal to (n+k)L0, where n and k are integers equal to or greater than 1;
and
removing the remaining resist layer and silicon-containing etch stop layer.

12 more elements

Dependencies are inferred from the claim text.