Lithographic Metrology Target Patterning Device

Solution Overview

Problem

Conventional lithographic apparatuses face challenges in optimizing metrology targets, as existing systems require new masks or reticle sets for design changes, leading to increased costs and reduced flexibility in evaluating new metrology target designs.

Innovation Solution

A lithographic apparatus with separate metrology target patterning device and controller, allowing independent adjustment of metrology target patterns without altering the product pattern, enabling real-time optimization and flexibility in metrology target design, including the use of arrays of individually controllable elements or masks for efficient pattern updates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If new masks or reticle sets are produced to optimize metrology target design, then metrology target performance is improved, but manufacturing cost increases and evaluation speed decreases

Engineering Contradiction:

Improvemetrology target performanceVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent segments the patterning device into two independent parts: a product patterning device for manufacturing product patterns and a metrology target patterning device for creating metrology targets. This segmentation allows the metrology target pattern to be independently adjusted without requiring new product masks, thereby reducing manufacturing costs while maintaining optimization capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The metrology target patterning device is designed to be dynamically adjustable, allowing frequent changes to metrology target designs without producing new physical masks. The controller can modify the metrology target pattern in real-time, enabling rapid evaluation of different designs and eliminating the need for expensive mask re fabrication.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If new masks or reticle sets are produced to optimize metrology target design, then metrology target performance is improved, but the speed of evaluating new designs decreases

Engineering Contradiction:

Improvemetrology target performanceVSAvoidevaluation speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The metrology target patterning device is designed to be dynamically adjustable, allowing frequent changes to metrology target designs without producing new physical masks. The controller can modify the metrology target pattern in real-time, enabling rapid evaluation of different designs and eliminating the need for expensive mask re fabrication.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses a programmable metrology target patterning device that can replicate different metrology target designs through software control rather than physical mask changes. This digital copying approach allows instant switching between different metrology target configurations, dramatically accelerating the evaluation process.

Inventive Principle:

Principle #26Copying

3Stability of the object's composition

If the product pattern is fixed on the mask, then product manufacturing stability is improved, but flexibility to change metrology targets decreases

Engineering Contradiction:

Improveproduct pattern stabilityVSAvoidmetrology target flexibility

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent segments the patterning device into two independent parts: a product patterning device for manufacturing product patterns and a metrology target patterning device for creating metrology targets. This segmentation allows the metrology target pattern to be independently adjusted without requiring new product masks, thereby reducing manufacturing costs while maintaining optimization capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lithographic apparatus is designed with multi-functionality, where a single system can handle both product pattern manufacturing and metrology target creation. The metrology target patterning device can be programmed with different patterns while the product patterning device maintains its fixed function, achieving both stability and versatility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS7573574B2Lithographic apparatus and device manufacturing method

Publication Date: 2009.08.11 ASML NETHERLANDS BV

AI summary

A lithographic apparatus and method comprise an illumination system arranged to provide a radiation beam, a support structure configured to support a product patterning device and a metrology target patterning device. The product patterning device imparts a radiation beam derived from the illumination system with a product pattern in its cross-section representing features of a product device to be formed. The metrology target patterning device imparts the radiation beam with a metrology target pattern in its cross-section representing at least one metrology target. The product patterning device is separate from the metrology target patterning device. A substrate table holds a substrate. A projection system project the radiation patterned by the product patterning device and the metrology target patterning device onto a target portion of the substrate. A metrology target patterning device controller adjusts the metrology target pattern independently of the product pattern.