MgO Single-Crystal Substrate Peeling by Internal Laser Marking

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Solution Overview

Problem

The increasing demand for thin magnesium oxide single crystal substrates with fewer lattice defects poses a challenge due to the high cost and limited reusability of magnesium oxide substrates used in diamond substrate manufacturing, necessitating an efficient method for obtaining thin, high-quality substrates.

Innovation Solution

A substrate manufacturing method involving a laser condensing means that irradiates a magnesium oxide single crystal substrate with a high-power density laser beam, forming processing marks in parallel lines and causing planar peeling, allowing for the efficient production of thin substrates with reduced lattice defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a magnesium oxide substrate is peeled off and separated to obtain a thin substrate, then the substrate thickness is reduced and reusability is improved, but the substrate may develop lattice defects and the peeling process becomes complex

Engineering Contradiction:
Improvesubstrate thicknessVSAvoidlattice defect density
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by forming processing marks on the substrate surface before the actual peeling process. These marks are created by irradiating the substrate with a laser beam that has been condensed by a condenser, creating predetermined locations that facilitate controlled peeling while minimizing lattice defects in the resulting thin substrate

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces mechanical peeling methods with a laser-based approach. Instead of using mechanical force to peel the substrate, which can cause lattice defects, the invention uses laser irradiation to create processing marks that enable controlled peeling, thereby reducing damage to the crystal lattice structure

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

2Ease of manufacture

If conventional peeling methods are used to obtain thin substrates, then substrate reusability is improved, but the process complexity and cost increase

Engineering Contradiction:
Improvesubstrate reusabilityVSAvoidpeeling process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical peeling systems with a simpler laser-based system. By using laser irradiation through a condenser to create processing marks, the invention eliminates the need for complex mechanical peeling equipment while achieving the same goal of substrate reusability

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

Solution Approach 2:

The patent changes the parameters of the laser beam by using a condenser to condense the laser beam to a specific diameter (0.1 mm to 1.0 mm) and controlling the irradiation conditions. This parameter control allows for precise formation of processing marks that facilitate easy peeling without requiring complex additional equipment

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 easy and cost-effective production of thin magnesium oxide single crystal substrates with reduced lattice defects, enhancing substrate reusability and contributing to cost reduction in diamond substrate manufacturing.

Implementation Method 1

irradiating a laser beam to a surface of the magnesium oxide single crystal substrate and condensing the laser beam into an inner portion of the single crystal member under designated irradiation conditions

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

forming processing marks to sequentially allow planar peeling

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3467159B1Substrate manufacturing method
Publication Date: 2023.01.11 SHIN ETSU POLYMER CO LTD
  • EP3467159B1 patent drawingFigure 1A~1B
  • EP3467159B1 patent drawingFigure 2~3
  • EP3467159B1 patent drawingFigure 4

AI summary

A substrate manufacturing method capable of easily obtaining a thin magnesium oxide single crystal substrate is provided. Performed is a first step of disposing a laser condensing means on a surface of a magnesium oxide single crystal substrate (20) of magnesium oxide to be irradiated in a non-contact manner, the laser condensing means being for condensing a laser beam. Then, a second step of causing planar peeling from a surface side of the magnesium oxide single crystal substrate (20) to be irradiated is performed. In this second step, a laser beam (B) is irradiated to the surface of the single crystal substrate (20) and the laser beam (B) is condensed into an inner portion of the single crystal substrate (20) under designated irradiation conditions. Simultaneously with the irradiation and the condensation, the laser condensing means (14) and the single crystal substrate (20) are two-dimensionally moved relatively to each other. In this way, processing mark lines (LK), each of which is composed in such a manner that processing marks (K) formed by thermal processing are formed in line at an inner portion of a single crystal member, are formed in parallel to one another. At this time, overlapped line portions (DK) in which the processing marks (K) overlap one another are formed in at least a part of the processing mark lines (LK), whereby the planar peeling is caused from the irradiated surface (20r) side .