GaN Chip Sidewall Structure for Crack-Free Wafer Cleavage
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Solution Overview
Problem
Manufacturing semiconductor chips using gallium nitride wafers often results in cracks and excessive strain on the side surfaces during the division process.
Innovation Solution
The semiconductor chip is designed with a chip-constituting substrate containing hexagonal gallium nitride, where the surfaces and side surfaces are oriented along specific crystal planes ({0001} c-plane, {1-100} m-plane, and {11-20} a-plane) and include an altered layer of gallium oxide and gallium metal on the side surface, which facilitates easy cleavage and reduces strain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional division methods are used to manufacture semiconductor chips from gallium nitride wafers, then chip production can be achieved, but cracks and excessive strain occur on the side surfaces
Solution Approach 1:
The patent changes the physical-chemical parameters of the side surface by forming an altered layer with different composition (gallium oxide and gallium metal) and structure compared to the bulk gallium nitride. This parameter change makes the side surface more compliant and less prone to cracking during chip division while maintaining overall chip reliability
Solution Approach 2:
The patent applies local quality by creating an altered layer only on the side surface portions that will become the chip side surfaces, while the bulk material remains intact. This localized treatment addresses the specific problem of side surface cracking without affecting the overall chip structure and functionality
2Ease of manufacture
If standard wafer division processes are applied, then chips can be separated, but excessive strain is generated on the side surfaces
Solution Approach 1:
The altered layer with its distinct composition (gallium oxide and gallium metal) and structure provides a region of reduced mechanical strength and increased compliance, allowing the wafer to be divided with less applied force and reducing the strain transmitted to the chip side surfaces during the separation process
3Ease of manufacture
If the side surface is left in its original state, then manufacturing is simpler, but insulation is insufficient
Solution Approach 1:
The patent changes the chemical composition of the side surface by forming an altered layer containing gallium oxide, which is an insulating material. This compositional change provides the necessary electrical insulation on the chip side surfaces while the altered layer forms through controlled thermal processing that integrates well with existing manufacturing workflows
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 design suppresses the occurrence of cracks and excessive strain on the side surfaces, improves insulation, and enhances the handling and productivity of the semiconductor chips by allowing for easy separation and reuse of the wafer material.
Implementation Method 1
a side surface of the chip-constituting substrate includes an altered layer containing gallium oxide and gallium metal on a surface layer portion
Data Source
AI summary
A semiconductor chip includes a chip-constituting substrate having one surface, the other surface opposite to the one surface, and two pairs of opposing side surfaces connecting the one surface and the other surface. The one surface and the other surface are along one of a {0001} c-plane, a {1-100} m-plane, and a {11-20} a-plane. One of the two pairs of opposing side surfaces is along another one of the {0001} c-plane, the {1-100} m-plane, and the {11-20} a-plane. The other of the two pairs of opposing side surfaces is along the other of the {0001} c-plane, the {1-100} m-plane, and the {11-20} a-plane. The side surface includes an altered layer containing gallium oxide and gallium metal in a surface layer portion in a depth direction which is a normal direction to the side surface.