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US 5,851,701 AGranted
Atom lithographic mask having diffraction grating and attenuated phase shifters
AssigneeMicron Technology, Inc.
InventorJ. Brett Rolson
Life of this patent
Estimating the term…
Abstract
An ATOM lithographic mask includes a transparent substrate having a pattern of attenuated phase shifters and a diffraction grating aligned with the attenuated phase shifters. The attenuated phase shifters form the primary mask pattern, while the diffraction grating diffracts exposure energy directed through the mask to provide off axis illumination for the attenuated phase shifters. The diffraction grating includes chromeless phase shifters formed using an additive or subtractive process. Both the attenuated phase shifters and diffraction grating can be formed as simple line-space patterns or in other patterns as required. In an alternate embodiment the diffraction grating is formed on a separate mask.
Claims37
A lithographic mask comprising:
- a transparent substrate;
- a pattern of attenuated phase shifters proximate to a first side of the substrate, the attenuated phase shifters comprising an absorbing layer configured to absorb and phase shift an exposure energy directed through the mask;
- and
- a diffraction grating formed proximate to a second side of the substrate in alignment with the pattern of attenuated phase shifters and configured to diffract the exposure energy to illuminate the attenuated phase shifters and print a plurality of features corresponding to the attenuated phase shifters on a target.
1 more element
A lithographic mask comprising:
- a transparent substrate;
- a plurality of attenuated phase shifters formed proximate to a first side of the substrate, the attenuated phase shifters comprising an absorbing material configured to absorb and phase shift an exposure energy directed through the mask;
- and
- a plurality of diffraction phase shifters formed proximate to a second side of the substrate in alignment with the attenuated phase shifters, the diffraction phase shifters configured to phase shift and diffract the exposure energy to provide off axis illumination for the attenuated phase shifters and to project a pattern of features corresponding to the attenuated phase shifters on a target.
1 more element
A lithographic mask comprising:
- a transparent substrate having a first side and a second opposing side;
- a mask pattern on the first side of the substrate comprising a plurality of attenuated phase shifters, each phase shifter comprising an absorbing layer configured to absorb and phase shift an exposure energy passing therethrough by an amount equal to .pi. or odd multiple thereof;
- and
- a grating pattern formed on the second side of the substrate in alignment with the mask pattern, the grating pattern comprising a plurality of parallel spaced grooves etched into the substrate to a depth selected to phase shift and diffract the exposure energy passing there through to provide off axis illumination of the attenuated phase shifters for printing the mask pattern on a target.
1 more element
A lithographic mask comprising:
- a transparent substrate having a first side and a second side;
- a plurality of attenuated phase shifters on the first side of the substrate forming a mash pattern, the attenuated phase shifters comprising an absorbing layer and a dielectric layer configured to absorb and phase shift an exposure energy directed through the mask;
- and
- a plurality of chase shifters on the second side of the substrate in alignment with the attenuated phase shifters, the phase shifters comprising a transparent material deposited on the substrate to a thickness selected to phase shift the exposure energy for illuminating the attenuated phase shifters for projecting the mask pattern on a target.
1 more element
A lithographic mask comprising:
- a substrate having a first side and a second opposing side;
- a mask pattern on the first side of the substrate comprising a plurality of attenuated phase shifters, each attenuated phase shifter comprising an absorbing layer configured to absorb and phase shift an exposure energy directed through the mask;
- and
- a grating pattern formed on the second side of the substrate in alignment with the mask pattern, the grating pattern comprising a plurality of parallel spaced phase shift grooves etched into the substrate to a depth to diffract and phase shift the exposure energy for illuminating the attenuated phase shifters and protecting the mask pattern onto a target.
1 more element
A method for fabricating a lithographic mask comprising:
- providing a transparent substrate having a first side and an opposing second side;
- forming a plurality of attenuated phase shifters on the first side, the attenuated phase shifters comprising an absorbing layer configured to absorb and phase shift an exposure energy transmitted through the mask during a lithographic process;
- and
- forming a plurality of phase shifters on the second side, the phase shifters configured to phase shift and diffract the exposure energy to provide off axis illumination for the attenuated phase shifters.
1 more element
A lithographic system comprising:
- an exposure source for providing an exposure energy for patterning a layer of resist on a target;
- a mask configured to transmit the exposure energy onto the target;
- the mask comprising a plurality of attenuated phase shifters, each attenuated phase shifter comprising an absorbing layer configured to absorb and phase shift the exposure energy transmitted through the mask;
- and
- a diffraction grating formed on the mask in alignment with the attenuated phase shifters, the diffraction grating comprising a plurality of phase shifters configured to diffract the exposure energy to provide off axis illumination for the attenuated phase shifters during patterning of the layer of resist.
2 more elements
A lithographic system comprising:
- an exposure source for providing an exposure energy;
- a mask comprising a transparent substrate configured to project the exposure energy onto a target;
- a plurality of attenuated phase shifters formed proximate to a first side of the substrate, each attenuated phase shifter comprising an absorbing layer configured to absorb and phase shift the exposure energy by an amount equal to .pi. or odd multiple thereof;
- and
- a plurality of diffraction phase shifters formed proximate to a second side of the substrate in alignment with the attenuated phase shifters, the diffraction phase shifters comprising a diffraction grating configured to diffract the exposure energy to provide off axis illumination for the attenuated phase shifters for printing features corresponding to the attenuated phase shifters on the target.
2 more elements
Dependencies are inferred from the claim text.