Semiconductor Defect Removal With Dual-Laser Metal Opening

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Solution Overview

Problem

The migration of metal constituting the electrode in semiconductor devices can cause short-circuiting, which is not effectively addressed in existing manufacturing processes.

Innovation Solution

A method involving the use of two lasers with different wavelengths to remove specific portions of the semiconductor layer and metal film, where a first laser emitting ultraviolet light removes defects, and a second laser emitting red or infrared light forms a larger hole through the metal film, reducing the likelihood of metal migration and short-circuiting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single laser is used to remove defects in the semiconductor layer, then the defect removal process is simple, but metal migration occurs causing short-circuiting

Engineering Contradiction:

Improvelaser processing systemVSAvoidshort-circuit prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent divides the laser processing into two separate stages using two different lasers: a first laser (excimer laser) removes the defect in the semiconductor layer, while a second laser (CO2 laser) removes the metal film in a larger overlapping area. This segmentation prevents metal migration by ensuring complete removal of metal in the defect region without requiring a single complex laser system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary approach by using two different laser types with different wavelengths and interaction mechanisms. The first laser (ultraviolet/excimer) targets the semiconductor layer, while the second laser (infrared/CO2) targets the metal film. This intermediary division of labor between two specialized lasers effectively prevents metal migration that would occur with a single laser system.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a larger area of metal film is removed to prevent metal migration, then short-circuiting is reduced, but the metal film area is reduced

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidmetal film area

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by removing the metal film only in the specific area where it is needed for defect removal and where overlap with the semiconductor defect occurs. The second laser removes metal film in a localized region that overlaps with the first laser's processing area, preventing metal migration exactly where it would cause short-circuits, while preserving metal film in other areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses partial action by removing only the necessary portion of the metal film - specifically the area overlapping with the semiconductor defect region. This is excessive removal only where needed (the overlapping area), not across the entire metal film, thus preventing short-circuits while minimizing loss of functional metal film area.

Inventive Principle:

Principle #16Partial or excessive action

3Manufacturing precision

If ultraviolet laser is used to remove semiconductor layer, then defect removal is effective, but laser-induced deterioration occurs

Engineering Contradiction:

Improvedefect removal precisionVSAvoidlaser-induced deterioration

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful effect of ultraviolet laser-induced deterioration by separating the metal film removal function from the semiconductor defect removal function. The second laser (CO2/infrared) removes the metal film without causing the same type of deterioration in the semiconductor layer, as it operates at a different wavelength that is less harmful to the semiconductor material while still effective for metal ablation.

Inventive Principle:

Principle #2Taking out (Extraction)

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 approach effectively reduces the occurrence of short-circuits by minimizing metal migration to the interface between semiconductor layers, while also reducing laser-induced deterioration of the semiconductor layer.

Implementation Method 1

removing a first portion of the semiconductor layer by irradiation with a first laser emitting ultraviolet light

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

removing a second portion of the metal film by irradiation with a second laser emitting red or infrared light

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS12593534B2Method of producing semiconductor device

Publication Date: 2026.03.31 NICHIA CORP

AI summary

A method of producing a semiconductor device, the method includes steps of: detecting a defect included in a semiconductor layer; forming a metal film on the semiconductor layer; after forming the metal film on the semiconductor layer, exposing the semiconductor layer through the metal film by removing a portion of the metal film by irradiation with a first laser emitting red or infrared light; and after the step of exposing the semiconductor layer, removing a portion of the semiconductor layer by irradiation with a second laser emitting ultraviolet light, said portion of the semiconductor layer including the defect. A diameter of said portion of the metal film is greater than a diameter of said portion of the semiconductor layer in a plan view. Said portion of the metal film overlaps with said portion of the semiconductor layer in the plan view.