Optical Overlay Measurement for Pattern Deformation Compensation
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Solution Overview
Problem
The overlay precision in semiconductor manufacturing, particularly in photolithography, is often compromised due to deformation of patterns during etching processes, leading to inaccuracies in pattern transfer and increased costs associated with compensating for deviations.
Innovation Solution
A method involving dual optical overlay precision measurements with different wavelengths or polarization directions to detect deformation, followed by compensation processing using first and second overlay precision deviation information to adjust the photoresist layer formation and etching processes, ensuring accurate pattern transfer and improved semiconductor structure precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If single optical overlay precision measurement is used, then detection process is simple, but measurement precision is insufficient due to pattern deformation
Solution Approach 1:
The patent applies parameter changes by performing overlay precision measurements using different wavelengths or polarization directions of light. This allows the detection system to capture pattern deformation information that would be invisible to a single measurement configuration, thereby improving measurement accuracy without requiring complex additional hardware
Solution Approach 2:
The patent implements feedback by comparing overlay precision information from multiple measurements with different wavelengths or polarization directions. The system uses this comparative feedback to detect pattern deformation and compensate for measurement errors, achieving higher precision through iterative refinement
2Manufacturing precision
If overlay deviation compensation is performed, then manufacturing precision is improved, but loss of time increases due to additional detection and compensation steps
Solution Approach 1:
The patent applies preliminary action by performing overlay precision measurements and detecting pattern deformation before the etching process. This allows compensation parameters to be determined in advance, enabling real-time correction during etching without adding significant time to the overall manufacturing process
Solution Approach 2:
The patent replaces complex mechanical measurement and adjustment systems with optical measurement and computational compensation. By using optical wavelengths and polarization directions to detect deformation and calculate compensation parameters, the system achieves high precision with minimal additional time compared to traditional mechanical methods
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
This approach enhances the overlay precision of semiconductor structures by accurately determining pattern deformation and adjusting processes accordingly, reducing the number of discarded wafers and subsequent treatment costs, while improving the precision and stability of semiconductor structures.
Implementation Method 1
performing a first detection on the wafer to-be-detected using an optical overlay precision measurement and acquiring first overlay precision information of the photoresist layer
Implementation Method 2
the optical overlay precision measurement includes one of an overlay precision measurement based on imaging and image recognition and an overlay precision measurement based on diffraction
Data Source
AI summary
A method for detecting an overlay precision and a method for compensating an overlay deviation are provided. The method for detecting the overlay precision includes providing a wafer to-be-detected, where the wafer to-be-detected includes a photoresist layer which has been exposed and developed; performing a first detection on the wafer to-be-detected using an optical overlay precision measurement and acquiring first overlay precision information of the photoresist layer; performing a second detection on the wafer to-be-detected using the optical overlay precision measurement, and acquiring second overlay precision information of the photoresist layer, where a wavelength or a polarization direction of a light source of the second detection is different from a wavelength or a polarization direction of a light source of the first detection; and acquiring overlay precision deviation information of the wafer to-be-detected according to the first overlay precision information and the second overlay precision information.