Microlithography Overlay Correction via Actuator Deformation
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Solution Overview
Problem
Existing microlithography techniques face challenges in achieving precise alignment and overlay accuracy due to lens distortions, chuck-induced wafer distortions, and image placement errors, leading to significant overlay errors and reduced production yield, with prior solutions requiring high computational power and being inaccurate.
Innovation Solution
A system and method that determine deformation parameters for patterned devices to minimize dimensional variations by comparing spatial variations between recorded and reference patterns, using actuators to apply deformation forces with predetermined constraints, thereby correcting alignment and overlay errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If prior art alignment correction methods are used, then alignment accuracy at alignment marks is improved, but computational requirements increase significantly and system cost increases
Solution Approach 1:
The patent extracts and corrects overlay errors by measuring and compensating for distortions at alignment marks, separating the alignment correction function from the full pattern correction function. This allows targeted correction of alignment-related errors without requiring computationally intensive analysis of the entire pattern field.
Solution Approach 2:
The system performs preliminary measurements of alignment marks and calculation of deformation parameters before the actual patterning process. By pre-determining the necessary corrections based on alignment mark positions and measured distortions, the system avoids the need for complex real-time computational corrections during pattern transfer.
2Measurement precision
If prior art alignment correction methods are used, then alignment accuracy at alignment marks is improved, but system cost increases
Solution Approach 1:
The patent extracts and corrects overlay errors by measuring and compensating for distortions at alignment marks, separating the alignment correction function from the full pattern correction function. This allows targeted correction of alignment-related errors without requiring computationally intensive analysis of the entire pattern field.
Solution Approach 2:
The system performs preliminary measurements of alignment marks and calculation of deformation parameters before the actual patterning process. By pre-determining the necessary corrections based on alignment mark positions and measured distortions, the system avoids the need for complex real-time computational corrections during pattern transfer.
3Ease of manufacture
If lens distortions and chuck-induced wafer distortions are not corrected, then manufacturing process is simpler, but overlay accuracy deteriorates significantly
Solution Approach 1:
The system measures actual alignment mark positions and compares them against expected positions to determine distortion characteristics. This feedback information is then used to calculate deformation parameters that compensate for lens and chuck-induced distortions, enabling correction of overlay errors without requiring complex real-time adjustments during manufacturing.
Solution Approach 2:
The system performs preliminary measurements of alignment marks and calculation of deformation parameters before the actual patterning process. By pre-determining the necessary corrections based on alignment mark positions and measured distortions, the system avoids the need for complex real-time computational corrections during pattern transfer.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively reduces overlay errors by selectively deforming patterned devices, improving alignment and overlay accuracy with reduced computational requirements, enhancing production yield and precision.
Implementation Method 1
determine deformation forces to apply to the patterned device to attenuate the dimensional variations
Data Source
AI summary
The present invention provides a method for determining the forces to be applied to a substrate in order to deform the same and correct for overlay misalignment.