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US 8,647,554 B2Granted
Residual layer thickness measurement and correction
AssigneeMolecular Imprints, Inc.
InventorsChristopher Ellis Jones, Niyaz Khusnatdinov, Stephen C. Johnson, Philip D. Schumaker, Pankaj B. Lad
Life of this patent
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Abstract
In nano-imprint lithography it is important to detect thickness non-uniformity of a residual layer formed on a substrate. Such non-uniformity is compensated such that a uniform residual layer may be formed. Compensation is performed by calculating a corrected fluid drop pattern.
Claims20
In an imprint lithography system, a method comprising:
- depositing a plurality of drops of polymerizable imprint fluid on a substrate, the plurality of drops having a drop pattern in which each of the plurality of drops has an assigned size and position on the substrate;
- performing a first imprint of the plurality of drops of polymerizable imprint fluid by varying the distance between a mold and the substrate to define a desired volume therebetween filled by the imprint fluid and then solidifying the imprint fluid resulting in a first patterned imprinted layer having a residual layer;
- measuring a variation of thicknesses of sub-portions of the residual layer at a plurality of points;
- calculating a new drop pattern that compensates for nonuniformities in the thickness of the residual layer by adjusting the assigned size and position of certain ones of the plurality of drops;
- and
- performing a second imprint of a plurality of drops using the new drop pattern resulting in a second imprinted layer having a uniform residual layer thickness.
3 more elements
In an imprint lithography system, a method comprising:
- imprinting a first field on a substrate using a first drop pattern of polymerizable fluid, the first drop pattern having a plurality of drops with each drop assigned a size and a position on the substrate, the first field formed by solidifying the polymerizable fluid between a mold and the substrate, the formed first field having a first residual layer;
- measuring thickness of the first residual layer across a dense array of points in the imprinted first field using a film thickness measurement tool;
- altering the first drop pattern based on the thickness measurements of the first residual layer to provide a second drop pattern, the second drop pattern configured to provide a substantially uniform residual layer;
- and
- imprinting a second field using the second drop pattern.
2 more elements
An imprint lithography method comprising:
- depositing a plurality of drops of polymerizable imprint fluid on a substrate, the plurality of drops having a drop pattern in which each of the plurality of drops has an assigned size and position on the substrate;
- varying the distance between an imprint lithography template having a patterning surface thereon and the substrate to define a desired volume therebetween filled by the imprint fluid;
- solidifying the imprint fluid to form a first patterned layer conforming to the patterning surface, the patterned layer having a residual layer;
- separating the imprint lithography template from the formed first patterned layer;
- measuring the thickness of the residual layer at a plurality of points;
- mapping the thickness of the residual layer as a two dimensional function, f(x,y) with an assigned thickness for each measured point;
- calculating the average thickness, g(x,y), of the residual layer;
- calculating the deviation from the average as w(x,y)=g(x,y)−f(x,y);
- and
- altering the first drop pattern by calculating offsets in the x and y direction based on g(x,y) and adjusting local unit fluid volume, number of drps, position of drops and drop volume based on deviation w(x,y) to provide a second drop pattern that provides for a substantially uniform residual layer.
7 more elements
Dependencies are inferred from the claim text.