Imprint Air Curtain Control for Material Evaporation and Particle Shielding
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Solution Overview
Problem
In imprint processing, uncured imprint material exposed to an air curtain can evaporate, leading to pattern defects, especially when processing multiple shot regions consecutively, as existing techniques fail to adequately control gas flow to prevent evaporation during the time uncured material is exposed.
Innovation Solution
An imprint apparatus with a control unit that adjusts the gas flow amount around the mold and substrate to reduce evaporation by decreasing the gas flow when uncured imprint material is present under the outlet, ensuring the gas flow returns to a higher amount when no uncured material is present, thereby forming a sufficient air curtain to prevent particle invasion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a gas flow (air curtain) is formed to shield the space between the mold and substrate, then particle invasion is prevented, but uncured imprint material evaporates
Solution Approach 1:
The gas flow amount is dynamically adjusted based on the presence and position of uncured imprint material. The control unit increases gas flow when no uncured material is present to prevent particle invasion, and decreases gas flow when uncured material is present to prevent evaporation, thus resolving the contradiction between these two protective functions
Solution Approach 2:
The flow amount parameter of the gas is changed according to the processing state. By switching between a first flow amount (higher) for particle protection and a second flow amount (lower) for evaporation prevention, the system optimizes both protection functions at different stages of the imprint process
2Productivity
If imprint processing is performed consecutively on multiple shot regions, then productivity is improved, but uncured imprint material evaporates during exposure time
Solution Approach 1:
The control unit monitors the position of the mold and substrate to detect the presence of uncured imprint material in the gas flow path. Based on this feedback, it automatically adjusts the gas flow amount to prevent evaporation during the extended exposure time inherent in consecutive multi-region processing, thereby maintaining both productivity and material integrity
3Loss of substance
If gas flow amount is reduced to prevent evaporation, then imprint material is preserved, but air curtain shielding effect is insufficient
Solution Approach 1:
The gas flow operates in periodic cycles: a first flow amount is supplied during periods when no uncured material is present to maintain strong particle shielding, and a second flow amount is supplied during periods when uncured material is present to prevent evaporation. This periodic switching ensures both protection functions are fulfilled at appropriate times
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 effectively prevents evaporation of uncured imprint material and ensures high accuracy in forming patterns on the substrate by dynamically controlling the gas flow, addressing the issue of pattern defects caused by evaporation in consecutive imprint processing.
Implementation Method 1
a forming unit including an outlet configured to blow out gas towards the substrate side from the mold side and configured to form, by the gas, an air flow that surrounds a space between the mold and the substrate
Implementation Method 2
there is a possibility that the imprint material will evaporate... controlling the forming unit such that a flow amount of the gas blown out from the outlet becomes a second flow amount which is less than a first flow amount
Data Source
AI summary
The present invention provides an imprint apparatus for performing imprint processing of forming a pattern of an imprint material on a substrate by using a mold, the imprint apparatus including a forming unit including an outlet configured to blow out a gas towards the substrate side from the mold side and configured to form, by the gas, an air flow that surrounds a space between the mold and the substrate, and a control unit configured to control the forming unit when the imprint processing is consecutively performed on a plurality of shot regions on the substrate after an uncured imprint material has been supplied thereto.