Exposing method
AssigneeKabushiki Kaisha Toshiba
InventorsManabu Takakuwa, Keita Asanuma, Tatsuhiko Higashiki
Life of this patent
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Abstract
Lens distortion correction is characterized by obtaining a correction parameter by using the difference between the latest QC data used when exposing a overlaying layer and the latest QC data used when exposing a overlaid layer.
Claims14
An exposing method of exposing an overlaying layer by aligning with the pattern of an overlaid layer by using an exposure unit of the scan exposing type which performs exposures in a shot area by moving a reticle and a wafer synchronously along the scanning direction, the exposing method comprising:
- preparing a reticle having a matrix of four or more marks in the scanning direction and four or more in the direction orthogonal to the scanning direction;
- transferring the marks formed on the reticle to each shot area of a first pilot wafer, by using a first exposure unit which is used for exposing the overlaid layer;
- detecting the position coordinates of the marks transferred to each shot area of the first pilot wafer in a predetermined coordinate systems;
- transferring the marks formed on the reticle to each shot area of a second pilot wafer, by using a second exposure unit which is used for exposing the overlaying layer;
- detecting the position coordinates of the marks transferred to each shot area of the second pilot wafer in the predetermined coordinate systems;
- referring to the position coordinates of the marks transferred by using the first and second exposure units;
- calculating the difference between the respective coordinate elements of the two referenced position coordinates;
- calculating from the calculated difference a correction parameter for correcting a lens aberration;
- and
- exposing the overlaying layer, in the state where the optics of the second exposure unit are being corrected based on the calculated correction parameter.
An exposing method of exposing an overlaying layer by aligning with the pattern of an overlaid layer by using an exposure unit of the scan exposing type which performs exposures in a shot area by moving a reticle and a wafer synchronously along the scanning direction, the exposing method comprising:
- preparing a first reticle which is used for exposing the overlaid layer and has three or more marks formed along the scanning direction;
- preparing a second reticle which is used for exposing the overlaying layer and has three or more marks formed along the scanning direction;
- detecting the position coordinates of the marks formed on the second reticle in a predetermined coordinate systems;
- transferring the marks formed on the first reticle to a first wafer;
- detecting the position coordinates of the marks transferred to each shot area of the first wafer in the coordinate systems;
- calculating the difference between the respective coordinate elements of the position coordinates of the marks transferred to the first wafer and the position coordinates of the marks formed on the second reticle;
- calculating from the calculated difference a correction parameter for correcting the 0th- to third-order errors which occur while moving the reticle and wafer in the scanning direction;
- and
- exposing the overlaying layer by using the second reticle, in the state where the errors are being corrected based on the correction parameter.
An exposing method of exposing an overlaying layer by aligning with the pattern of an overlaid layer by using an exposure unit of the scan exposing type which performs exposures in a shot area by moving a reticle and a wafer synchronously along the scanning direction, the exposing method comprising:
- preparing a first reticle which is used for exposing the overlaid layer and has three or more marks formed along the scanning direction;
- preparing a second reticle which is used for exposing the overlaying layer and has three or more marks formed along the scanning direction;
- detecting the position coordinates of the marks formed on the second reticle in a predetermined coordinate systems;
- transferring the marks formed on the first reticle to the overlaid layer of the first wafer;
- detecting the position coordinates of the marks transferred to each shot area of the overlaid layer in the coordinate systems;
- calculating the barycentric coordinates of each shot area from the position information of the marks transferred to each shot area of the overlaid layer;
- calculating the barycentric coordinates of the marks based on the position coordinates of each mark formed on the second reticle;
- calculating the difference between the two barycentric coordinates;
- calculating from the calculated difference a correction parameter for correcting the 0th- to third-order errors which occur while moving the wafer in the stepping direction;
- and
- exposing the overlaying layer, in the state where the errors are being corrected based on the correction parameter.
Dependencies are inferred from the claim text.