Patent ID: 9431219
Filing Date: 2016-08-30
CPC Classification: B81C,B82B,B82Y,C03C,G03F,G11B,H01L

Claim Text:
1. A method for making guiding lines on a substrate for directed self-assembly (DSA) of a block copolymer (BCP) having a natural pitch L 0 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 nL 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 nL removing the remaining resist layer and etch stop layer.