SOI Release Layer for Infrared Substrate Thinning

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Solution Overview

Problem

Current semiconductor-on-insulator (SOI) substrate processing methods, such as grinding, polishing, and etching, are inefficient and can cause stress and damage to the substrate.

Innovation Solution

Incorporating an embedded release layer made of a transition metal-containing material with high temperature stability and infrared energy absorption capabilities into the SOI substrates, allowing for rapid substrate thinning/removal through infrared ablation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If grinding, polishing and etching methods are used to remove the base substrate and insulator layer, then the substrate can be thinned, but the processing throughput is low and high stress and damage occur to the SOI substrate

Engineering Contradiction:

Improveprocessing throughputVSAvoidstress and damage to substrate

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical processing methods (grinding, polishing, etching) with a chemical/thermal process. An infrared-absorbing layer is introduced that can be selectively removed by infrared laser irradiation, converting mechanical substrate removal into a photothermal ablation process. This substitution eliminates mechanical stress and damage while dramatically increasing processing throughput.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The infrared-absorbing layer undergoes phase transition (ablation) when exposed to infrared energy. The layer is designed to absorb infrared radiation and convert it to heat, causing rapid heating and removal of the layer through phase change. This allows non-contact, stress-free removal of the base substrate and insulator layer at high speed.

Inventive Principle:

Principle #36Phase transitions

2Productivity

If an infrared-absorbing release layer is introduced into the SOI substrate, then rapid substrate thinning/removal can be achieved, but the device complexity increases

Engineering Contradiction:

Improvesubstrate thinning speedVSAvoidsubstrate structure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The infrared-absorbing layer serves as an intermediary element between the base substrate and the device layer. It is specifically designed to absorb infrared energy and facilitate selective removal of the base substrate and insulator layer while leaving the device layer intact. This intermediary layer enables high-speed processing without requiring fundamental changes to the overall substrate architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The infrared-absorbing layer is positioned specifically at the interface between the base substrate and the device layer, providing localized functionality. Only this specific layer possesses infrared absorption properties, allowing selective removal of underlying layers while preserving the device structure. This localized approach adds minimal complexity while achieving rapid thinning.

Inventive Principle:

Principle #3Local quality

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 embedded release layer enables efficient and stress-free substrate thinning/removal, improving processing throughput and reducing damage to the SOI substrate.

Implementation Method 1

The release layer of the present application is composed of a transition metal-containing material that has high temperature stability, is infrared energy absorbing

Methodology Applied

Scientific EffectInfrared energy absorption: Absorption (EM radiation)

Implementation Method 2

The presence of the embedded release layer in the SOI substrates allows for rapid substrate thinning/removal by infrared ablation

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

The release layer of the present application is composed of a transition metal-containing material that has high temperature stability, is infrared energy absorbing

Methodology Applied

Scientific EffectPhotothermal heating: Heating

Data Source

PatentUS20250048730A1Release layer containing semiconductor-on-insulator substrates

Publication Date: 2025.02.06 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

SOI substrates containing an embedded release layer that is composed of a transition metal-containing material that has high temperature stability, is infrared energy absorbing, and is compatible with complementary metal oxide semiconductor (CMOS), front-end-of-the-line (FEOL) and back-end-of-the-line (BEOL) processes are provided. The presence of the embedded release layer in the SOI substrates allows for rapid substrate thinning/removal by infrared ablation without the need of using grinding, polishing and etching methods.