Pellicle Manufacturing via Metal Intermediary for EUV Transmittance

Solution Overview

Problem

Existing methods for manufacturing pellicles with high EUV transmittance and production yield face challenges in depositing silicon nitride layers with thicknesses of equal to or less than 100 nm, and etching them to less than 5 nm without low yield due to technical limitations.

Innovation Solution

A method involving the formation of upper and lower silicon nitride layers on a wafer substrate, followed by etching the lower layer according to a pattern, forming a metal layer, etching the upper silicon nitride layer to a preset thickness, removing the metal layer, forming a graphene thin film, and etching the wafer substrate along the patterned lower silicon nitride layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the silicon nitride layer is deposited with a thickness of equal to or less than 100 nm, then the EUV transmittance is improved, but the deposition reliability deteriorates

Engineering Contradiction:

ImproveEUV transmittanceVSAvoiddeposition reliability

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by forming a metal layer on the lower silicon nitride layer before etching the upper layer. This metal layer serves as a protective and structural foundation that enables subsequent precise etching of the upper silicon nitride layer to the target thickness of 5 nm or less, ensuring both EUV transmittance and manufacturing reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The metal layer acts as an intermediary element between the lower silicon nitride layer and the upper silicon nitride layer. It provides a stable platform for pattern formation and etching operations, enabling precise control of the upper layer's thickness without compromising the structural integrity or reliability of the overall pellicle structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the silicon nitride layer is etched to a thickness of less than 5 nm, then the EUV transmittance is improved, but the production yield deteriorates

Engineering Contradiction:

ImproveEUV transmittanceVSAvoidproduction yield

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by forming a metal layer on the lower silicon nitride layer before etching the upper layer. This metal layer serves as a protective and structural foundation that enables subsequent precise etching of the upper silicon nitride layer to the target thickness of 5 nm or less, ensuring both EUV transmittance and manufacturing reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The metal layer acts as an intermediary element between the lower silicon nitride layer and the upper silicon nitride layer. It provides a stable platform for pattern formation and etching operations, enabling precise control of the upper layer's thickness without compromising the structural integrity or reliability of the overall pellicle structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Length of stationary object

If the silicon nitride layer is etched in a state of being a thin membrane, then the thickness is reduced to less than 5 nm, but the success rate deteriorates

Engineering Contradiction:

Improvesilicon nitride layer thicknessVSAvoidsuccess rate

Core Design Contradiction:

Length of stationary objectVSReliability

Solution Approach 1:

The patent applies preliminary action by forming a metal layer on the lower silicon nitride layer before etching the upper layer. This metal layer serves as a protective and structural foundation that enables subsequent precise etching of the upper silicon nitride layer to the target thickness of 5 nm or less, ensuring both EUV transmittance and manufacturing reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The metal layer acts as an intermediary element between the lower silicon nitride layer and the upper silicon nitride layer. It provides a stable platform for pattern formation and etching operations, enabling precise control of the upper layer's thickness without compromising the structural integrity or reliability of the overall pellicle structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method enables the stable etching of silicon nitride layers to a thickness of equal to or less than 5 nm, significantly increasing the pellicle yield and ensuring high EUV transmittance while maintaining the mechanical integrity of the pellicle.

Implementation Method 1

etching a deposited silicon nitride layer in a stable state to equal to or less than 5 nm

Methodology Applied

Scientific EffectDry etching:

Implementation Method 2

forming a graphene thin film on the upper silicon nitride layer

Methodology Applied

Scientific EffectDeposition: Deposition (physical)

Implementation Method 3

etching and removing the metal layer after the etching of the upper silicon nitride layer

Methodology Applied

Scientific EffectWet etching:

Data Source

PatentUS20250028238A1Method for manufacturing pellicle and pellicle manufactured thereby

Publication Date: 2025.01.23 GRAPHENELAB CO LTD

AI summary

A method for manufacturing the pellicle includes the steps of forming upper and lower silicon nitride layers on opposite surfaces of a wafer substrate, forming a metal layer on the lower silicon nitride layer, etching the upper silicon nitride layer to a preset thickness after the forming of the metal layer, etching and removing the metal layer after the etching of the upper silicon nitride layer, forming a graphene thin film on the upper silicon nitride layer, forming a pattern on the lower silicon nitride layer, etching the lower silicon nitride layer according to the formed pattern, and etching the wafer substrate along the lower silicon nitride layer etched according to the pattern.