Optical proximity correction
AssigneeASML Masktools Netherlands B.V.
InventorsJohn S. Petersen, Jang Fung Chen
Life of this patent
Estimating the term…
Abstract
Method for utilizing halftoning structures to manipulate the relative magnitudes of diffraction orders to ultimately construct the desired projected-image. At the resolution limit of the mask maker, this is especially useful for converting strongly shifted, no-0th-diffraction-order, equal-line-and-space chromeless phase edges to weak phase-shifters that have some 0th order. Halftoning creates an imbalance in the electric field between the shifted regions, and therefore results in the introduction of the 0th diffraction order.
Claims14
A method of transferring an image, including 0th diffraction order and ±1st diffraction orders, onto a material, said method comprising the steps of:
- fabricating a phase-shifting mask comprising at least one unattentuated, halftoned, phase-shift feature;
- and
- off-axis illuminating said mask such that radiation traverses said mask and impinges on said material.
A method of transferring an image, including 0th diffraction order and ±1st diffraction orders, onto a material, said method comprising the steps of:
- fabricating a phase-shifting mask comprising at least one feature, wherein said at least one feature includes halftoned, phase-shifted, transparent features;
- and
- off-axis illuminating said mask such that radiation passes through said mask onto said material.
A phase-shifting mask comprising at least two unattentuated, halftoned, phase-shift features having a width w, said features separated by a width substantially equal to w,
- wherein said mask provides an image including 0th diffraction order and ±1st diffraction orders, when illuminated.
A phase-shifting mask comprising at least two halftoned, phase-shifted, transparent features having a width w, said features separated by a width substantially equal to w,
- wherein said mask provides an image including 0th diffraction order and ±1st diffraction orders, when illuminated.
A device manufacturing method comprising the steps of:
- (a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material;
- (b) providing a projection beam of radiation using a radiation system;
- (c) using a pattern on a mask to endow the projection beam with a pattern in its cross-section;
- (d) projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material,
- wherein, in step (c):
- use is made of a phase-shifting mask comprising at least one unattentuated, halftoned, phase-shift feature;
- the mask is off-axis illuminated by the radiation system.
A device manufacturing method comprising the steps of:
- (a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material;
- (b) providing a projection beam of radiation using a radiation system;
- (c) using a pattern on a mask to endow the projection beam with a pattern in its cross-section;
- (d) projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material,
- wherein, in step (c):
- use is made of a phase-shifting mask comprising at least one feature, wherein said at least one feature includes halftoned, phase-shifted, transparent features;
- and
- the mask is off-axis illuminated by the radiation system.
Dependencies are inferred from the claim text.