US 8,911,920 B2Granted

Methods for fabricating EUV masks and methods for fabricating integrated circuits using such EUV masks

AssigneeGlobalfoundries Inc.

InventorsSudharshanan Raghunathan, Pawitter Mangat, Hui Peng Koh

Life of this patent

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Abstract

A method for fabricating integrated circuits includes fabricating an EUV mask by providing a photomask having a border region. A photoresist is formed over the photomask and has a border region overlying the border region of the photomask. The method exposes an inner portion and an outer portion of the photoresist border region. The method removes the inner portion and the outer portion to expose the border region of the photomask. The border region of the photomask is etched using the photoresist as a mask to form the EUV mask with a non-reflective border. The photoresist is removed from the EUV mask. The method includes forming another photoresist over a partially-fabricated integrated circuit layer and patterning the photoresist by exposure to EUV light reflected from the EUV mask to expose portions of the partially-fabricated integrated circuit layer. Portions of the partially-fabricated integrated circuit layer and the photoresist are removed.

Claims20

Dependent claims

A method for fabricating a portion of an integrated circuit, the method comprising:

fabricating an extreme ultraviolet (EUV) mask comprising:
providing a photomask substrate having a border region;
forming a first photoresist over the photomask substrate, the first photoresist having a border region overlying the border region of the photomask substrate;
exposing an inner portion of the border region of the first photoresist;
exposing an outer portion of the border region of the first photoresist;
removing the inner portion of the border region of the first photoresist and removing the outer portion of the border region of the first photoresist to expose the border region of the photomask substrate;
etching the border region of the photomask substrate using the first photoresist as a mask to form the EUV mask with a non-reflective border;
and
removing the first photoresist from the EUV mask;
forming a second photoresist over a layer of a partially-fabricated integrated circuit;
patterning the second photoresist by exposure to EUV light reflected from the EUV mask to expose portions of the layer of the partially-fabricated integrated circuit;
removing the portions of the layer of the partially-fabricated integrated circuit;
and
removing the second photoresist.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/840,790Filed 15 Mar 2013
Published: US 2014/0272677 A118 Sep 2014
Granted: 16 Dec 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

G03F 7/2022
Exposure; Apparatus therefor: multi-step exposure, e.g. hybrid; backside exposure; blanket exposure, e.g. for image reversal; edge exposure, e.g.…
G03F 1/22
Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles…
G03F
Photomechanical production of textured or patterned surfaces