Lithography Substrate Measurement Conditioning Fluid Path

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Solution Overview

Problem

Current lithographic apparatuses face challenges in achieving high precision for manufacturing devices with small features due to limitations in substrate measurement and processing precision.

Innovation Solution

A lithographic apparatus with a movable substrate table and a measuring system that directs measuring beams towards the substrate, accompanied by a conditioning system using a fluid flow control surface to condition the path of the measuring beams, ensuring accurate measurement and processing by maintaining a controlled environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If substrate measurement is performed using measuring beams in a lithographic apparatus, then substrate positioning accuracy is improved, but measurement precision deteriorates due to environmental disturbances in the unconditioned path

Engineering Contradiction:

Improvesubstrate measurement precisionVSAvoidenvironmental disturbances affecting measuring beams

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A conditioning fluid (such as nitrogen or filtered air) is introduced as an intermediary medium to fill the space between the measuring beams and the environment. This fluid acts as a mediator that blocks harmful environmental factors (dust, temperature variations, humidity) from affecting the measuring beams, while allowing the beams to pass through and perform substrate measurements accurately

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates an inert or controlled atmosphere by supplying conditioning fluid along the path of the measuring beams. This conditioned environment isolates the sensitive optical measurement process from external environmental disturbances, ensuring stable and precise measurements without direct exposure to uncontrolled ambient conditions

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Productivity

If the substrate table is moved to transfer substrate between measuring position and processing position, then productivity is improved, but manufacturing precision deteriorates due to positioning errors during movement

Engineering Contradiction:

Improvesubstrate processing throughputVSAvoidsubstrate positioning precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces purely mechanical positioning with a hybrid system that combines mechanical substrate table movement with optical measurement feedback. Measuring beams continuously monitor substrate position during and after movement, and measurement results are used to correct positioning errors, thereby maintaining high precision despite frequent table movements for productivity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The measuring system provides real-time feedback on substrate position and orientation after the substrate table moves between measuring and processing positions. This feedback enables dynamic correction of positioning errors, ensuring that manufacturing precision is maintained even as productivity increases through frequent substrate repositioning

Inventive Principle:

Principle #23Feedback

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 the precision of device manufacturing by providing accurate substrate positioning and processing, reducing measuring errors and improving the reproducibility of the measuring system, thereby enabling the production of devices with small features.

Implementation Method 1

A measuring system is configured to measure at least one aspect and/or characteristic of the substrate when the substrate table holds the substrate in the measuring position. The measuring system is configured to direct at least one measuring beam and/or field towards a surface of the substrate.

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

A conditioning system is configured to supply a conditioning fluid to at least part of a path of the measuring beam and/or field of the measuring system to condition the part of the path.

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 3

A projection system is configured to project a patterned radiation beam onto a target portion of the substrate when the substrate table holds the substrate in the substrate processing position.

Methodology Applied

Scientific EffectRadiation projection:

Data Source

PatentUS7542127B2Lithographic apparatus and method for manufacturing a device

Publication Date: 2009.06.02 ASML NETHERLANDS BV

AI summary

A lithographic apparatus is disclosed. The apparatus includes a substrate table constructed to hold a substrate. The substrate table is moveable to transfer the substrate between a substrate measuring position and a substrate processing position. The apparatus also includes a measuring system configured to measure at least one aspect or characteristic of the substrate when the substrate table holds the substrate in the measuring position. The measuring system is configured to direct at least one measuring beam and/or field towards a surface of the substrate. A projection system is configured to project a patterned radiation beam onto a target portion of the substrate when the substrate table holds the substrate in the substrate processing position, and a conditioning system is configured to supply a conditioning fluid to at least part of a path of the measuring beam and/or field of the measuring system to condition the part of the path.