Crack Stop Ring Trench for GaN-on-Si Epitaxy Crack Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor manufacturing is the propagation of cracks in stacked semiconductor substrates due to thermal expansion mismatch between silicon and gallium nitride layers, which can lead to yield loss and reliability issues in device regions.
Innovation Solution
A crack stop ring trench is introduced around the central device region, extending in a closed path between the central and peripheral regions of the substrate, preventing cracks from propagating into the device area by separating the peripheral region cracks from the central region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stacked semiconductor substrate structure is used to achieve high performance devices, then device performance is improved, but crack propagation occurs due to thermal expansion mismatch
Solution Approach 1:
The substrate is divided into a central region containing device regions and a peripheral region, separated by a crack stop ring trench. This segmentation isolates cracks that form in the peripheral region due to thermal expansion mismatch, preventing them from propagating into the central device regions while maintaining the overall stacked substrate structure for high performance devices.
Solution Approach 2:
A crack stop ring trench is introduced as an intermediary structure between the central and peripheral regions. This trench acts as a barrier that stops crack propagation from the peripheral region into the central device region, thereby protecting the devices from harmful cracks while preserving the benefits of the stacked substrate architecture.
2Stability of the object's composition
If the substrate is cooled from growth temperature, then crystalline structure is stabilized, but cracks form and propagate due to thermal contraction
Solution Approach 1:
The crack stop ring trench is formed in advance during the fabrication process, before the substrate undergoes cooling and crack formation. This preliminary structural preparation ensures that when cracks do form during thermal contraction, they are already blocked by the pre-existing trench, preventing propagation into the device regions.
Solution Approach 2:
The substrate is segmented into central and peripheral regions by the crack stop ring trench. This segmentation allows the peripheral region to undergo thermal contraction and form cracks without affecting the central device regions, thereby maintaining crystalline structure stability in the device areas while accommodating thermal stress in the peripheral areas.
3Reliability
If peripheral region is allowed to contain cracks, then central device region can be protected, but overall substrate integrity is compromised
Solution Approach 1:
The substrate is divided into central and peripheral regions separated by a crack stop ring trench. This segmentation allows the peripheral region to contain cracks without compromising the central device region integrity. The trench acts as a containment boundary, isolating cracks to the peripheral region while preserving substrate integrity in the critical device areas.
Solution Approach 2:
The harmful effect of crack propagation is extracted and confined to the peripheral region by the crack stop ring trench. Cracks are taken out from the overall substrate structure and isolated to the peripheral area, preventing them from affecting the central device region while maintaining the functional integrity of the substrate.
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 solution effectively prevents cracks from reaching the device regions, enhancing the yield, reliability, and performance of semiconductor devices by isolating the crack propagation, thereby maintaining the integrity of the semiconductor structure.
Implementation Method 1
one or more sidewalls defining a crack stop ring trench that continuously extends in a closed path between the central region and the peripheral region. The crack stop ring trench is configured to prevent a plurality of cracks within the peripheral region from propagating to the central region
Implementation Method 2
The challenge in semiconductor manufacturing is the propagation of cracks in stacked semiconductor substrates due to thermal expansion mismatch between silicon and gallium nitride layers
Data Source
AI summary
In some embodiments, the present disclosure relates to a semiconductor structure. The semiconductor substrate includes a semiconductor material over a base substrate. The semiconductor substrate has one or more sidewalls forming a crack stop trench that is laterally between a central region of the semiconductor substrate and a peripheral region of the semiconductor substrate that surrounds the central region. The peripheral region of the semiconductor substrate includes a plurality of cracks.