GaN Dicing Street Stop Islands to Block Film Splitting

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Solution Overview

Problem

GaN thin films in semiconductor devices tend to split during the dicing process due to stress, which can lead to peeling and malfunction of the transistors, and existing stress relaxation layers and stoppers are ineffective in preventing this split.

Innovation Solution

The implementation of stop islands made of SiN film at the intersections of dicing streets, with specific dimensions to prevent the propagation of splits in the GaN thin film, ensuring the film remains adhered to the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional manufacturing processes are used for high-aspect-ratio structures, then existing process compatibility is maintained, but particle contamination and planarity issues occur

Engineering Contradiction:
Improveprocess compatibilityVSAvoidparticle contamination
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The copper seed layer is deposited beforehand using a technique compatible with existing manufacturing processes, such as chemical vapor deposition or atomic layer deposition. This preliminary action prevents particle contamination during the main electroplating step while maintaining compatibility with conventional fabrication sequences

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the direct electroplating approach (which causes particle precipitation) with a two-step process where a copper seed layer is first deposited using vapor-phase techniques, then electroplating is performed on this smooth base, eliminating mechanical particle contamination issues

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

2Ease of operation

If copper plugs are formed in high-aspect-ratio holes, then via-hole connections are achieved, but aspect ratio causes particle precipitation and dishing

Engineering Contradiction:
Improvevia-hole connectionVSAvoidplug surface planarity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

A copper seed layer is formed on the inner wall of the high-aspect-ratio via-hole before filling with copper plugs. This preliminary layer provides a uniform surface that prevents particle precipitation and dishing during electroplating, maintaining both via-hole connectivity and surface planarity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent addresses the high-aspect-ratio challenge by adding a dimensional layer (the copper seed layer coating the inner wall) that transforms the problem from a vertical filling challenge to a surface deposition problem, enabling uniform coverage and preventing precipitation issues

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Prevents peeling of protective films from reaching element regions and effectively stops the propagation of splits in the dicing streets, maintaining the integrity and functionality of the semiconductor devices.

Implementation Method 1

a copper seed layer is formed on an inner wall of the via-hole

Methodology Applied
Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

copper plugs are formed by electroplating in a copper-containing solution

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentEP4160656B1Semiconductor device and method for manufacturing semiconductor device
Publication Date: 2026.04.22 MITSUBISHI ELECTRIC CORP
  • EP4160656B1 patent drawingFigure 1
  • EP4160656B1 patent drawingFigure 2~3
  • EP4160656B1 patent drawingFigure 4

AI summary

A split in a dicing street in a semiconductor film is prevented. A semiconductor device includes: a first dicing street passing between a plurality of element regions on which a plurality of protective films are formed one-to-one, the first dicing street extending along a first axis; a second dicing street passing between the plurality of element regions and extending along a second axis; and a stop island disposed on the upper surface of the semiconductor film at an intersection between the first dicing street and the second dicing street, the stop island being in non-contact with the plurality of element regions. X_si > X_ds and Y_si < Y_ds are satisfied.