Suspended Semiconductor Layer Transfer for Large Pressurized Cavities

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Solution Overview

Problem

Existing methods for transferring thin films over cavities, such as Smart Cut™, are limited to small cavities due to exfoliation phenomena, restricting their application to sizes of a few microns or tens of microns, and cannot effectively seal larger cavities without deformation or breakage.

Innovation Solution

A method involving the implantation of gaseous species into both the donor and receiving substrates, followed by diffusion and annealing, creates a counter-pressure within the cavity to promote lateral defect propagation, preventing blister formation and enabling the sealing of larger cavities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If Smart Cut™ technology is used to transfer thin layers onto cavities, then thin film transfer is achieved, but the cavity size is limited to a few microns or tens of microns due to exfoliation

Engineering Contradiction:
Improvethin film transfer precisionVSAvoidcavity size
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent introduces a preliminary action by forming an embrittlement plane in the donor substrate before the transfer process. This embrittlement plane, created through ion implantation, prepares the substrate for controlled fracture and enables the transfer of thin films over larger cavity areas by preventing exfoliation that would otherwise limit cavity size to only a few microns or tens of microns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by modifying the physical state of the donor substrate through ion implantation, which creates an embrittlement plane. This changes the mechanical properties of the substrate, allowing controlled fracture propagation that can span larger cavity areas without causing exfoliation, thus enabling thin film transfer onto cavities larger than the conventional few microns to tens of microns limit.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If larger cavities are sealed, then the applicability of Smart Cut™ technology is expanded, but exfoliation occurs leading to membrane deformation and breakage

Engineering Contradiction:
Improvecavity sealing applicabilityVSAvoidmembrane integrity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a preliminary action by forming an embrittlement plane in the donor substrate before the transfer process. This embrittlement plane, created through ion implantation, prepares the substrate for controlled fracture and enables the transfer of thin films over larger cavity areas by preventing exfoliation that would otherwise limit cavity size to only a few microns or tens of microns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by modifying the physical state of the donor substrate through ion implantation, which creates an embrittlement plane. This changes the mechanical properties of the substrate, allowing controlled fracture propagation that can span larger cavity areas without causing exfoliation, thus enabling thin film transfer onto cavities larger than the conventional few microns to tens of microns limit.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If thinning process is used to create suspension, then cavity sealing is achieved, but the process is time-consuming and costly

Engineering Contradiction:
Improvecavity sealing precisionVSAvoidfabrication speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the conventional mechanical thinning process with a fracture-based transfer method. Instead of gradually removing material through mechanical thinning, the invention uses ion implantation to create an embrittlement plane followed by controlled fracture, which rapidly separates the thin film from the donor substrate and transfers it to the cavity, significantly reducing fabrication time while maintaining sealing precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies parameter changes by modifying the physical state of the donor substrate through ion implantation, which creates an embrittlement plane. This changes the mechanical properties of the substrate, allowing controlled fracture propagation that can span larger cavity areas without causing exfoliation, thus enabling thin film transfer onto cavities larger than the conventional few microns to tens of microns limit.

Inventive Principle:
Principle #35Parameter changes

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

Enables the transfer and sealing of larger cavities by modifying defect growth patterns, allowing for the fabrication of devices with suspended membranes on cavities beyond the limitations of existing techniques.

Implementation Method 1

ionic species such as hydrogen and/or helium are implanted into a donor substrate to create a plane of embrittlement

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Implementation Method 2

This development requires an energy input, generally achieved through heat treatment at several hundred degrees, typically 500°C, for several tens of minutes

Methodology Applied
Scientific EffectThermal energy input: Heating

Implementation Method 3

This fracture separates the donor substrate along the weakening plane and a thin layer of the donor substrate is thus transferred onto the supporting substrate

Methodology Applied
Scientific EffectFracture mechanics: Fracture Mechanics

Data Source

PatentEP3878802B1Method for hanging a thin layer on a cavity with stiffening effect obtained by pressurisation of the cavity by implanted species
Publication Date: 2026.04.29 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3878802B1 patent drawingFigure 1~2
  • EP3878802B1 patent drawingFigure 3(A)~3(E)
  • EP3878802B1 patent drawingFigure 4~5

AI summary

The invention relates to a method for transferring a semiconductor layer from a donor substrate to a receiving substrate having an open cavity, comprising the steps of deforming a weakened plane in the donor substrate and creating, by bringing the donor and receiving substrates into contact, an assembly in which said cavity is embedded. This method includes, prior to the creation of the assembly, a step of implanting diffusing materials into the donor or receiving substrate and, subsequent to the creation of the assembly, a step of diffusing said materials into the cavity.