Imprint Apparatus Alignment via TTM Scope Contact Measurement
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Solution Overview
Problem
In imprint apparatuses, the global alignment method using a TTM scope leads to decreased overlay accuracy due to the inclination difference between the optical axis of the scope and the imprint head driving direction, which affects the precision of pattern formation on substrates during the photo-curing process.
Innovation Solution
The apparatus incorporates a measurement device with a TTM scope to detect mold and substrate marks while they are not in contact, and a controller to adjust the driving mechanisms based on the relative positions and inclination of the optical axis, ensuring accurate alignment and correcting for position shifts during the imprint process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the global alignment method using TTM scope is adopted in imprint apparatus, then the apparatus size can be reduced and cost decreased, but overlay accuracy deteriorates due to inclination difference between optical axis and driving direction
Solution Approach 1:
The patent changes the measurement parameter from proximity measurement (with spacing) to contact measurement (with zero spacing). By making the spacing between mold and substrate zero during measurement, the optical axis inclination effect is eliminated, thereby maintaining high overlay accuracy while using the compact TTM scope configuration
Solution Approach 2:
The patent replaces the conventional off-axis scope (OAS) mechanical configuration with a TTM scope configuration. By substituting the optical measurement path to go through the mold rather than from the side, the apparatus achieves compact size while the contact measurement method compensates for any optical axis inclination issues
2Ease of operation
If proximity measurement is performed with mold and substrate spaced apart, then alignment can be performed before contact, but position shift occurs due to optical axis inclination during head driving
Solution Approach 1:
The patent performs alignment measurement in advance before the imprint process, but crucially does so in a contact state rather than proximity state. This preliminary contact measurement establishes accurate relative positioning that accounts for the actual contact geometry, preventing position shifts during subsequent driving operations
Solution Approach 2:
The patent changes the spacing parameter from a few ten μm (proximity measurement) to zero (contact measurement). This parameter change eliminates the optical axis inclination effect that causes position shifts during head driving, while still allowing alignment to be performed before the actual imprint contact
3Manufacturing precision
If die-by-die alignment method with contact measurement is used, then overlay accuracy can be maintained, but substrate stage movement range is limited
Solution Approach 1:
The patent makes the contact measurement method universal by applying it to the global alignment framework. The measurement device can measure marks across multiple shot regions even in contact state, combining the overlay accuracy benefits of contact measurement with the broad coverage capability of global alignment, thereby enabling larger substrate stage movement ranges
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 solution enhances overlay accuracy by correcting for position shifts and inclination errors, improving the precision of pattern formation and reducing the influence of process factors, thereby increasing productivity and stability in semiconductor device manufacturing.
Implementation Method 1
a scope for detecting, through the mold, a mold mark formed on the mold and a substrate mark formed on the substrate in a state in which the mold and the imprint material are not in contact with each other
Implementation Method 2
a controller configured to control the second driving mechanism based on information of a relationship between a moving amount along the driving axis of at least one of the mold holder and the substrate holder, and change in relative positions between the mold mark and the substrate mark
Data Source
AI summary
An imprint apparatus includes: a first driving mechanism configured to move at least one of a mold holder and a substrate holder such that a mold and an imprint material are contact with each other; a second driving mechanism configured to move at least one of the holders such that the substrate is aligned with the mold; a measurement device configured to measure relative positions between a mold mark and a substrate mark in a state in which the mold and the imprint material are not in contact with each other; and a controller configured to control the second driving mechanism based on information of a relationship between a moving amount of at least one of the holders, and change in relative positions between the marks, information of the moving amount, and information of the measured relative positions.