Stacked Structure Transfer via Buried Weakened Plane Separation

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Solution Overview

Problem

Current methods for transferring thick membranes onto functionalized substrates in microelectronics often degrade the membrane quality due to mechanical and chemical treatments, and struggle with precise detachment at weakened interfaces, leading to thickness non-uniformities and component degradation.

Innovation Solution

A method involving the formation of a buried fragile plane in a support substrate by light ion implantation, followed by assembly and mechanical/chemical thinning to create a donor substrate, which is then separated along this plane to form a stacked structure with a surface film on a recipient substrate, allowing for precise control and minimizing degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If mechanical and chemical thinning is applied to the donor substrate, then the thick membrane can be transferred onto the functionalized substrate, but the membrane quality degrades with cracks, exfoliated areas, and thickness non-uniformities

Engineering Contradiction:
Improvemembrane thickness uniformityVSAvoidmembrane integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The donor substrate is segmented into two parts by creating a buried fragile plane through light ion implantation. This plane acts as a predetermined separation interface that divides the substrate into a support substrate and a donor layer, allowing clean separation without mechanical stress on the membrane itself

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mechanical thinning process is replaced by a chemical separation process. Instead of mechanically thinning the donor substrate which causes stress and degradation, the patent uses light ion implantation to create a fragile plane that can be separated by chemical etching or thermal treatment, substituting mechanical action with a gentler chemical/thermal process

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

2Ease of manufacture

If detachment is achieved by inserting a blade or applying tensile stresses, then the membrane can be separated from the donor substrate, but the functionalized substrate and membrane undergo degradation

Engineering Contradiction:
Improvedetachment processVSAvoidsubstrate and membrane quality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The fragile plane is created in advance through light ion implantation before the detachment step. This preliminary action prepares a predetermined separation interface that makes subsequent detachment easy and clean, eliminating the need for blade insertion or tensile stress application that would degrade the components

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The buried fragile plane acts as an intermediary layer between the support substrate and the donor layer. This intermediate structure facilitates clean separation by providing a dedicated separation interface that protects both the membrane and functionalized substrate from direct mechanical contact and stress during detachment

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If conventional ion implantation equipment is used for Smart Cut process, then thin membranes can be transferred, but thick membranes from several microns to tens of microns cannot be transferred

Engineering Contradiction:
Improvemembrane thickness rangeVSAvoidtransfer quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent changes the ion implantation parameters by using light ions (such as hydrogen or helium) at low energies (1-100 keV) to create a fragile plane very close to the surface (0.1-5 microns depth). This parameter change enables the process to work with thick membranes that cannot be handled by conventional Smart Cut, while maintaining high transfer quality through the predetermined separation interface

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

This method enables the transfer of high-quality, thick surface films with excellent uniformity and integrity, suitable for microelectronic components, while avoiding the limitations of existing techniques that cause membrane degradation and non-uniformity.

Implementation Method 1

forming a buried fragile plane in the support substrate by implanting light ions through the front face of said substrate

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Data Source

PatentEP4128330B1Method for producing a stacked structure
Publication Date: 2024.11.27 SOITEC SA
  • EP4128330B1 patent drawingFigure 1a~1c(ii)
  • EP4128330B1 patent drawingFigure 2a~2c
  • EP4128330B1 patent drawingFigure 2d~2f

AI summary

The invention relates to a method for producing a stacked structure comprising a receiver substrate and a surface film, the method comprising the following steps: a) providing a carrier substrate and an initial substrate, each having a front face and a back face, b) forming a buried weakened plane in the carrier substrate or in the initial substrate by implanting light ions through the front face of either of said substrates, c) joining the carrier substrate and the initial substrate via their respective front faces, d) mechanically and/or chemically thinning the initial substrate from its back face to form a donor substrate comprising a donor layer originating from the initial substrate and arranged on the carrier substrate, and the buried weakened plane present in the carrier substrate or in the donor layer, the donor substrate having a front face on the side of the donor layer and a back face on the side of the carrier substrate, e) providing a receiver substrate having a front face and a back face, f) joining the donor substrate and the receiver substrate via their respective front faces, g) separating along the buried weakened plane so as to form the stacked structure comprising the receiver substrate and the surface film including all or part of the donor layer.