Imprint Apparatus Alignment Control via Dynamic Gain Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the process of miniaturizing semiconductor devices, the alignment between a mold and a substrate in imprint techniques is hindered by viscoelastic forces generated due to the resin sandwiched between them, leading to decreased accuracy and increased time for alignment.
Innovation Solution
An imprint apparatus equipped with a detection unit to monitor displacement between the mold and substrate, an amplifier to adjust alignment signals, and a control unit that manages force application by changing amplifier gain based on movement thresholds to mitigate viscoelastic forces during alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the mold and substrate are relatively moved for alignment in a state where the mold is in contact with the resin on the substrate, then alignment is performed, but force in the direction parallel with the contact surface acts as disturbance force, degrading controllability in the alignment
Solution Approach 1:
The patent applies preliminary action by performing alignment in a non-contact state before the mold contacts the resin. The alignment detection unit measures displacement between the mold and substrate while they are relatively moved without contact, allowing alignment to be established before the harmful viscoelastic forces of resin contact interfere with controllability.
2Manufacturing precision
If the resin thickness is thinned to several dozen nm or less for miniaturization, then etching process is improved, but the resin obtains large viscoelasticity property, generating disturbance force during alignment
Solution Approach 1:
The patent extracts the alignment function from the contact state by performing alignment in a non-contact condition. The alignment detection unit enables displacement measurement without requiring the mold to be in contact with the resin, thereby separating the alignment operation from the harmful viscoelastic effects that occur only when the thin resin layer is compressed between the mold and substrate.
3Reliability
If foreign particle is sandwiched between the mold and substrate, then the mold and substrate mesh with each other, but force in the direction parallel with the contact surface is applied, degrading alignment accuracy
Solution Approach 1:
The patent performs alignment in a non-contact state before any potential foreign particles can be sandwiched between the mold and substrate. By establishing the positional relationship while the mold and substrate are still separated, the system avoids the meshing effect and parallel forces that would occur if alignment were attempted after foreign particle contamination.
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 controllability and accuracy of the alignment process, reducing the time required for precise alignment between the mold and substrate, thereby improving overlay accuracy in semiconductor device manufacturing.
Implementation Method 1
a detection unit configured to output a signal of displacement between the mold and the substrate by detecting positions of the mold and the substrate in a direction parallel with a surface of the substrate
Implementation Method 2
an amplifier configured to amplify the signal
Implementation Method 3
a control unit configured to perform alignment between the mold and the substrate based on the signal that has been amplified by the amplifier
Implementation Method 4
It is known that a liquid held in a small gap with such an order is structured and obtains a large viscoelasticity property. When the mold and the substrate are relatively moved for alignment in a state where the mold is in contact with the resin on the substrate, force is applied to the mold and the substrate in a direction (shearing direction) parallel with a contact surface, due to the viscoelasticity of the resin
Data Source
AI summary
The present invention provides an imprint apparatus including an amplifier configured to amplify a signal of displacement between a mold and a substrate, and a control unit configured to perform alignment between the mold and the substrate based on the amplified signal, wherein the control unit performs the alignment through a first operation of moving the substrate with respect to the mold in a first direction and a second operation of moving the substrate with respect to the mold in a second direction that is opposite to the first direction, and in the first operation, the control unit sets the gain of the amplifier to a first gain and changes the gain of the amplifier from the first gain to a second gain.