Abstract:
Disclosed is a method of determining a pellicle compensation correction which compensates for a distortion of a patterning device resultant from mounting of a pellicle onto the patterning device. The method comprises determining a pellicle induced distortion from a first shape associated with the patterning device without the pellicle mounted and a second shape associated with the patterning device with the pellicle mounted, the pellicle induced distortion describing the distortion of the patterning device due to the pellicle being mounted. The determined pellicle induced distortion is then used to calculate the pellicle compensation correction for a lithographic exposure step using the patterning device.
Abstract:
Disclosed is a method of determining at least one exposure parameter such as focus and/or dose. The method comprises obtaining production metrology data for a plurality of structures; grouping said production metrology data into a plurality of neighbor groups, each neighbor group describing a different arrangement of said structures; obtaining pre-calibrated sensitivity relationship data for each of said plurality of neighbor groups or different combinations thereof, and inferring said at least one exposure parameter from the production metrology data and pre-calibrated sensitivity relationship data.
Abstract:
A method to change an etch parameter of a substrate etching process, the method comprising: making a first measurement of a first metric associated with a structure on a substrate before being etched; making a second measurement of a second metric associated with a structure on a substrate after being etched; and changing the etch parameter based on a difference between the first measurement and the second measurement.
Abstract:
A method of determining an optimal operational parameter setting of a metrology system is described. Free-form wafer shape measurements are performed 304. A model is applied 306, transforming the measured warp to modeled warp scaling values 308. Wafers are clamped to a chuck in a lithographic apparatus, causing wafer deformation. Alignment marks are measured using the scanner alignment system 312 with four alignment measurement colors. Scaling values 314 thus obtained are corrected 316 with the modeled warp scaling values 308 to determine corrected scaling values 318. The optimal alignment measurement color is determined, based on the corrected scaling values 318. Scaling values are selected that were measured using the optimal alignment measurement color and, at step 326, the wafer grid 328 is determined using the selected scaling values. A wafer is exposed 330 using the determined wafer grid 328 to correct exposure of the wafer.