2D Interlace Scanning for Microlithography Throughput Scaling
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Solution Overview
Problem
Existing methods for writing or reading patterns using large sparse 2D point arrays do not scale throughput with array size, leading to inefficiencies and repetition of data, limiting the use of massive arrays in microlithography and inspection applications.
Innovation Solution
The method involves determining the necessary density of grid points and finding the optimal combination of rotation and distance between laser pulses to create a desired density using all or almost all elements in the array, allowing for efficient scanning and writing with large arrays without limits on throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If large sparse 2D point arrays are used for scanning, then throughput should increase, but throughput does not scale with array size and data repetition occurs
Solution Approach 1:
The patent introduces a second dimension of scanning by moving the array not only in the x-direction but also in the y-direction between pulses. This creates a two-dimensional scanning pattern that allows each array element to write to unique locations on the workpiece, eliminating data repetition and enabling throughput to scale with array size.
Solution Approach 2:
The patent implements dynamic positioning of the array between pulses, where the array location is varied based on the pulse number and scan parameters. This dynamic movement ensures that different array elements write to different locations, preventing repetition and maximizing the utilization of large arrays.
2Ease of operation
If simple raster scanning is used, then implementation is easy, but hardware signatures appear in the image and flexibility is limited
Solution Approach 1:
The patent employs asymmetric scanning patterns where the array is positioned at different locations and orientations for different pulses. This asymmetric approach breaks the regular patterns that create hardware signatures, while the overall process remains systematically controllable through the pulse number and scan parameters.
Solution Approach 2:
The patent varies multiple parameters including array position, scan direction, and pulse timing to create complex scanning patterns. By changing these parameters dynamically, the system eliminates hardware signatures and provides flexibility in creating different grid patterns on the workpiece.
Data Source
AI summary
The current invention relates to writing or reading a pattern on a surface, such as in microlithography or inspection of mircrolithographic patterns. In particular, Applicant discloses systems recording or reading images by scanning sparse 2D point arrays or grids across the surface, e.g., multiple optical, electron or particle beams modulated in parallel. The scanning and repeated reading or writing creates a dense pixel or spot grid on the workpiece. The grid may be created by various arrays: arrays of light sources, e.g., laser or LED arrays, by lenslet arrays where each lenslet has its own modulator, by aperture plates for particle beams, or arrays of near-field emitters or mechanical probes. For reading systems, the point grid may be created by a sparse point matrix illumination and/or a detector array where each detector element sees only one spot. The idea behind the use of large arrays is to improve throughput. However, the throughput does not scale with the array size, since above a certain size of arrays, previously known schemes fall into in their own tracks and start repeating the same data over and over again. This application discloses methods to scan workpieces with large arrays while preserving the scaling of throughput proportional to array size, even for very large arrays, in fact essentially without limits.