Method and apparatus for alignment optimization with respect to plurality of layers for writing different layers with different machine configurations
AssigneeMicronic Mydata AB
InventorsMikael Wahlsten, Per-Erik Gustafsson
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Abstract
A method of patterning a plurality of layers of a work piece in a series of write machines, wherein errors due to different transformation capabilities of different machines are compensated by distributing the errors over the plurality of layers.
Claims17
A method of patterning a plurality of layers of a work piece in a series of writing cycles in one or a plurality of write machines, applied when writing a first pattern on a first layer N of the workpiece, wherein a boundary condition for the available accuracy in fitting a second pattern for a subsequent layer N+1 to the first layer is determined;
- the method comprising the steps of:
- a. Receiving a priori information about the limitation in performing a limited transformation of the second pattern for said subsequent layer N+1;
- b. Calculating:
- i. a best fit transformation of the first pattern for the first layer N that renders a best fit to a preceding layer N−1 using alignment transformation available for writing on the first layer N, and
- ii. the deviation from a perfect fit of the best fit transformation ;
- c. Calculating:
- i. a limited transformation applied in transforming the second pattern for the second layer N+1 to fit the orientation to said preceding layer N−1, and
- ii. the deviation from a perfect fit of the limited transformation;
- d. Calculating the difference in the deviation between said best fit transformation and said limited transformation;
- e. Calculating a compensation of the best fit transformation by adding a selectable part of said difference in deviations;
- f. Calculating an adjusted first pattern comprising said compensation;
- g. Verifying that said adjusted first pattern is within alignment tolerances for the first layer N:
- h. Writing, if positively verified, said adjusted first pattern on said first layer N.
A method of patterning a plurality of layers of a work piece in a series of writing cycles in one or a plurality of write machines,
- at least one layer of the work piece having a plurality of dies distributed thereon;
- each die being associated with an original circuit pattern and being represented by original circuit pattern data;
- each die being associated with measurement data of alignment features of the respective layer;
- the method comprising the steps of:
- c. Calculating a first transformation for alignment of a first pattern for a first layer based on measurement data for the first layer and on transformation limitations of a first machine configured to write the first layer;
- d. Calculating a second transformation for alignment of a second pattern for a subsequent layer based on a transformation type to be used for a machine configured to write the second layer;
- e. Calculating a difference between first and second transformations and then distributing the difference between first and second transformations;
- f. Verifying that said adjusted first pattern is within alignment tolerances for the first layer and/or the second layer, respectively;
- g. Writing a pattern on the first and second layers according to the respective first and second compensated transformations.
Dependencies are inferred from the claim text.