Back to results
US 8,389,183 B2Granted
Chromeless phase-shifting photomask with undercut rim-shifting element
AssigneeInternational Business Machines Corporation
InventorsBrent A. Anderson, Jed H. Rankin
Life of this patent
Estimating the term…
Abstract
A phase-shifting photomask with a self aligned undercut rim-shifting element and methods for its manufacture are provided. One embodiment of the invention provides a method of manufacturing a phase-shifting photomask having a self aligned rim-shifting element, the method comprising: applying a patterning film to a first portion of a transparent substrate; etching the substrate to a depth to remove a second portion of the substrate not beneath the patterning film; etching the first portion of the substrate to undercut an area beneath the patterning film; and removing the patterning film, wherein the etched substrate forms a self-aligned undercut rim-shifting element.
Claims6
A photomask comprising:
- a transparent substrate including:
- a first portion;
- a second portion atop the first portion, the second portion comprising a first pedestal and including an undercut adjacent the first portion;
- a third portion atop the first portion, the third portion comprising a second pedestal;
- and
- a fourth portion adjacent the third portion and atop the first portion;
- a first sidewall spacer along the second portion of the transparent substrate;
- and
- a second sidewall spacer along the third portion of the transparent substrate,
- wherein the first, second, third, and fourth portions of the transparent substrate are disposed to provide a plurality of transmission paths through the photomask, the plurality of transmission paths including:
- a first transmission path through the first portion and producing a first phase shift;
- a second transmission path through the second portion and the first portion, producing a second phase shift different from the first phase shift;
- a third transmission path through the second portion, an atmosphere within the undercut, and the first portion, producing a third phase shift intermediate the first phase shift and the second phase shift;
- a fourth transmission path through the first sidewall spacer, an atmosphere beneath the first sidewall spacer, and the first portion of the transparent substrate, producing a fourth phase shift intermediate the first phase shift and the third phase shift;
- a fifth transmission path through the third portion and the first portion, producing a fifth phase shift substantially equal to the second phase shift;
- a sixth transmission path through the fourth portion of the transparent substrate and the first portion of the transparent substrate, producing a sixth phase shift intermediate the first phase shift and the fifth phase shift;
- and
- a seventh transmission path through the second sidewall spacer, the fourth portion of the transparent substrate, and the first portion of the transparent substrate, producing a seventh phase shift intermediate the fifth phase shift and the sixth phase shift.
15 more elements
A photomask comprising:
- a transparent substrate including:
- a first portion;
- a second portion atop the first portion, the second portion comprising a first pedestal and including an undercut adjacent the first portion;
- a third portion atop the first portion, the third portion comprising a second pedestal;
- and
- a fourth portion adjacent the third portion and atop the first portion;
- and
- a sidewall spacer along the second portion of the transparent substrate;
- wherein the first, second, third, and fourth portions of the transparent substrate are disposed to provide a plurality of transmission paths through the photomask, the plurality of transmission paths including:
- a first transmission path through the first portion and producing a first phase shift;
- a second transmission path through the second portion and the first portion and producing a second phase shift different from the first phase shift;
- a third transmission path through the second portion, an atmosphere within the undercut, and the first portion and producing a third phase shift intermediate the first phase shift and the second phase shift;
- a fourth transmission path through the sidewall spacer, an atmosphere beneath the sidewall spacer, and the first portion of the transparent substrate producing a fourth phase shift intermediate the first phase shift and the third phase shift;
- a fifth transmission path through the third portion of the transparent substrate and the first portion of the transparent substrate, producing a fifth phase shift substantially the same as the second phase shift;
- and
- a sixth transmission path through the fourth portion of the transparent substrate and the first portion of the transparent substrate, producing a sixth phase shift intermediate the first phase shift and the second phase shift.
13 more elements
Dependencies are inferred from the claim text.