Lithographic Object Holder Composite Manufacturing

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Solution Overview

Problem

In lithographic apparatuses, existing substrate holders face challenges with electrostatic clamping performance, substrate temperature control, and the reliability of grounding layers, particularly due to imperfections in isolation layers and the complexity of manufacturing electrically functional components like sensors and heaters directly on the holder.

Innovation Solution

A method of manufacturing an object holder using a composite structure with a carrier sheet and a layered structure comprising SiO2 formed by thermal oxidation, which includes projections for electrostatic clamping and a grounding layer between the dielectric layer and projections for improved electrical connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a grounding layer is provided on projections for electrostatic clamping, then electrical connectivity is improved, but the grounding layer may stick to the object being held requiring roughening treatments

Engineering Contradiction:
Improveelectrical connectivityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

A dielectric layer is introduced as an intermediary between the grounding layer and the projection surface. This dielectric layer prevents direct contact between the grounding layer and the object being held, eliminating the sticking problem while maintaining electrical connectivity through the dielectric material.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The grounding layer is repositioned from the outer surface of projections to an intermediate position between the dielectric layer and projections. This spatial reconfiguration allows the grounding function to be maintained without the adverse sticking effect on the object surface.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If sensors and heaters are manufactured directly on the holder, then integration is improved, but manufacturing complexity and reliability risks increase

Engineering Contradiction:
ImproveintegrationVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Sensors and heaters are manufactured and tested on a separate carrier sheet before being transferred to the final holder assembly. This preliminary manufacturing and testing allows for quality control and validation before integration, reducing manufacturing complexity and reliability risks in the final assembly process.

Inventive Principle:
Principle #10Preliminary action

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 electrostatic clamping performance, improves substrate temperature control accuracy, and simplifies the manufacturing process by reducing imperfections and increasing the reliability of the grounding layer, leading to more efficient and durable substrate holders.

Implementation Method 1

a layered structure comprising one or a plurality of layers and formed on the carrier sheet

Methodology Applied
Scientific EffectThermal oxidation: Oxidation

Implementation Method 2

Two methods of clamping the substrate in place are known - vacuum clamping and electrostatic clamping

Methodology Applied
Scientific EffectElectrostatic clamping: Electrostatics

Implementation Method 3

connecting the composite structure to a surface of the main body

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP2979135B1Object holder and method of manufacturing an object holder
Publication Date: 2019.11.13 ASML NETHERLANDS BV
  • EP2979135B1 patent drawingFigure 1
  • EP2979135B1 patent drawingFigure 2~4
  • EP2979135B1 patent drawingFigure 5~6

AI summary

A method of manufacturing an object holder for use in a lithographic apparatus, the object holder comprising one or more electrically functional components, the method comprising: using a composite structure comprising a carrier sheet different from a main body of the object holder and a layered structure comprising one or a plurality of layers and formed on the carrier sheet; connecting the composite structure to a surface of the main body such that the layered structure is between the carrier sheet and the surface of the main body; and removing the carrier sheet from the composite structure, leaving the layered structure connected to the main body.