SiC Pellicle Manufacturing via Controlled Carbon Concentration

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Solution Overview

Problem

Pellicle films made of SiC face challenges in achieving high transmittance and mechanical strength, leading to issues such as cracking and peeling when attempting to increase area or thinness, which results in a low production yield ratio.

Innovation Solution

A pellicle comprising a supporting member with a ring-like shape and a SiC film of varying carbon concentrations, where the SiC film is formed on one surface of the supporting member with specific thickness and carbon concentrations, and the method involves carbonizing the Si substrate, forming epitaxial SiC films, and using wet etching to expose the film, ensuring the film's mechanical strength and transmittance are maintained.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a pellicle is stretched to reduce wrinkles, then surface flatness improves, but the pellicle may break due to excessive stress

Engineering Contradiction:
Improvesurface flatnessVSAvoidpellicle integrity
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The pellicle is pre-stretched in the vertical direction during formation to create initial tension that prevents wrinkles during subsequent horizontal stretching. This preliminary action reduces the stress required during final stretching, preventing breakage while achieving surface flatness.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical state and mechanical properties of the pellicle by controlling the solidification process and applying controlled tension during formation. By adjusting the stretching parameters and solidification conditions, the pellicle achieves optimal strength-to-flatness ratio.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If a pellicle is formed by stretching a liquid crystal polymer solution, then large-area flat surface is achieved, but wrinkles occur due to uneven stress distribution

Engineering Contradiction:
Improvepellicle areaVSAvoidsurface uniformity
Core Design Contradiction:
Area of stationary objectVSShape

Solution Approach 1:

The pellicle is pre-stretched in the vertical direction during formation to create initial tension that prevents wrinkles during subsequent horizontal stretching. This preliminary action ensures uniform stress distribution across the large area, maintaining surface uniformity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies dynamic stretching where the pellicle is stretched in multiple directions with varying degrees of tension. The stretching process is controlled to be gradual and differential, allowing the material to adapt and preventing uneven stress concentration that causes wrinkles.

Inventive Principle:
Principle #15Dynamics

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 solution enhances the production yield ratio by maintaining mechanical strength and achieving high transmittance, preventing cracking and peeling, thus enabling the formation of large area, thin SiC films with improved quality.

Implementation Method 1

solidification of the liquid crystal polymer solution

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 2

stretched in the vertical direction to a predetermined length before solidification; stretched in the horizontal direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3667417B1Pellicle and method for producing pellicle
Publication Date: 2023.06.28 AIR WATER INC
  • EP3667417B1 patent drawingFigure 1
  • EP3667417B1 patent drawingFigure 2(a)~2(c)
  • EP3667417B1 patent drawingFigure 3

AI summary

A pellicle and a method for manufacturing a pellicle that can improve the production yield ratio are provided. A method for manufacturing a pellicle comprises a step to prepare a supporting member containing Si, and a step to form a pellicle film on a top surface of the supporting member. The step to form the pellicle film includes: a step to form a SiC film with a first average carbon concentration on the top surface of the supporting member by carbonizing Si, and a step to form a SiC film with a second average carbon concentration different from the first average carbon concentration on the top surface of the SiC film. The method for manufacturing a pellicle further comprises a step to exposes at least a part of the reverse side of the SiC film by wet etching.