Angled Sidewall Patterning Device for Lithography

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Solution Overview

Problem

Standard attenuated phase shift patterning devices in lithographic apparatuses suffer from high radiation loss due to a low percentage of radiation intensity being diffracted into the numerical aperture (NA), leading to increased required doses and reduced throughput.

Innovation Solution

A patterning device with a second component having angled sidewalls, where at least one part of the sidewall extends away from the first component at an angle less than 85 degrees, partially absorbing and transmitting radiation to increase diffraction into the NA, thereby reducing radiation loss and improving throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If standard attenuated phase shift patterning devices are used, then the device structure is simple, but the radiation loss is high and throughput is low

Engineering Contradiction:

ImprovethroughputVSAvoidradiation loss

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The sidewall of the second component is designed with a curved profile instead of a straight vertical wall. The curvature is defined such that the angle between the sidewall and the plane parallel to the first component surface varies along the height, being less than 85 degrees at least at one location. This curved geometry optimizes the diffraction of radiation into the numerical aperture of the lithographic apparatus, reducing radiation loss and improving throughput.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Use of energy by moving object

If standard attenuated phase shift patterning devices are used, then the manufacturing process is simple, but the required dose is high

Engineering Contradiction:

Improverequired doseVSAvoiddevice fabrication

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The curved sidewall profile of the second component is engineered to enhance diffraction efficiency, thereby reducing the required radiation dose for achieving the desired patterning effect. The curvature parameter is optimized to redirect more radiation into the useful diffraction orders within the numerical aperture, reducing waste and the total dose requirement.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Loss of energy

If the sidewall angle is increased to redirect radiation, then radiation diffraction into NA improves, but manufacturing precision requirements increase

Engineering Contradiction:

Improveradiation diffraction efficiencyVSAvoidsidewall angle control

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

Instead of requiring a single precise angle, the invention employs a curved sidewall where the angle varies continuously or in steps along the height of the second component. This curvature approach distributes the diffraction function across multiple angles, achieving high radiation efficiency while providing manufacturing flexibility. The curve can be defined by multiple parameters that are easier to control with standard fabrication tolerances.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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

The angled sidewall design enhances radiation diffraction into the NA, decreasing the required dose and improving the quality and quantity of features printed on the substrate, resulting in increased throughput and yield compared to standard devices.

Implementation Method 1

a second component covering at least a portion of a surface of the first component and configured to at least partially absorb the radiation incident on the second component

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

This may have an advantage that more radiation may be diffracted into the numerical aperture (NA) of the lithographic apparatus which may decrease the required dose of radiation

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 3

The second component may at least partially transmit the radiation incident on the second component so as to give the radiation emerging from the second component a phase shift relative to the radiation reflected off another portion of the first component not covered by the second component

Methodology Applied

Scientific EffectPhase shift:

Data Source

PatentUS20220214610A1A patterning device

Publication Date: 2022.07.07 ASML NETHERLANDS BV

AI summary

A patterning device configured for use in a lithographic apparatus, the lithographic apparatus being configured to use radiation for imaging a pattern at the patterning device via projection optics onto a substrate. The patterning device including a first component for reflecting and/or transmitting the radiation, and a second component covering at least a portion of a surface of the first component and configured to at least partially absorb the radiation incident on the second component. The second component has a sidewall, wherein at least one part of the sidewall extends away from the first component at an angle, the angle being with respect to a plane parallel to the surface of the first component, and wherein the angle is less than 85 degrees.