Ridge Semiconductor Substrate for Low-Stress Nitride Layer Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor substrates face challenges in reducing internal stress and warping, which complicates the peeling process of nitride semiconductor layers, leading to increased defects and reduced efficiency in semiconductor devices.
Innovation Solution
The semiconductor substrate design includes a ridge substrate with a nitride semiconductor layer featuring tether and wing portions that are recessed and floating off the surface, reducing internal stress and contact area, allowing for easier peeling by creating a cleavage plane at the wing portion ends.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the nitride semiconductor layer is grown on a flat substrate surface, then the growth area is maximized, but internal stress accumulates causing warping and making peeling difficult
Solution Approach 1:
The substrate surface is segmented into ridge portions and recessed portions, creating a non-flat surface structure. The nitride semiconductor layer is grown selectively on the ridge portions, dividing the growth area into discrete segments that reduce internal stress accumulation while maintaining sufficient total growth area.
Solution Approach 2:
The substrate surface is given different local qualities through the ridge and recessed portion structure. The ridge portions provide growth-friendly surfaces while the recessed portions act as stress relief zones and peeling initiation points, creating local variations that simultaneously enable growth and facilitate peeling.
2Stability of the object's composition
If the nitride semiconductor layer is grown to reduce warping, then substrate stability is improved, but the peeling process becomes more complex and defect-prone
Solution Approach 1:
The ridge and recessed portion structure is prepared in advance on the substrate before growing the nitride semiconductor layer. This preliminary action creates built-in stress management features that stabilize the substrate during growth while simultaneously preparing designated peeling initiation points, simplifying the subsequent peeling process.
Solution Approach 2:
The recessed portions act as intermediary elements between the nitride semiconductor layer and the substrate. These intermediaries provide stress relief during growth to maintain substrate stability, and serve as controlled initiation points for peeling, reducing process complexity and defects.
3Reliability
If the contact area between nitride semiconductor layer and substrate is increased, then growth stability is improved, but peeling efficiency decreases
Solution Approach 1:
The contact area is segmented into discrete ridge portions rather than a continuous flat surface. This segmentation provides sufficient total contact area for stable growth on each ridge portion, while the gaps between ridges (recessed portions) reduce overall adhesion to enable efficient peeling.
Solution Approach 2:
Different local contact qualities are created: the ridge portions provide localized high-contact areas for stable growth, while the recessed portions provide low-contact or no-contact zones that reduce overall adhesion strength, enabling efficient peeling while maintaining growth stability where needed.
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 reduces warping and enhances the peeling efficiency of nitride semiconductor layers, improving the quality and yield of semiconductor devices by minimizing defects and facilitating easy separation into individual chips.
Implementation Method 1
a method (ELO method) in which a mask pattern including a mask portion and an opening portion is formed on a base substrate including a seed layer, and a nitride semiconductor layer is laterally grown on the mask portion by using the seed layer exposed in the opening portion as a growth starting point
Data Source
Figure 1~3
Figure 4~6
Figure 7
AI summary
The present semiconductor substrate includes a ridge substrate including a ridge portion extending in a first direction and a first surface portion and a second surface portion being located lower than the ridge portion and adjacent to each other via the ridge portion, and a nitride semiconductor layer located on the ridge substrate, in which the nitride semiconductor layer includes a first tether portion located on the ridge portion, a first wing portion connected to the first tether portion in a state of floating off the first surface portion, and a first recessed portion located on the ridge portion and having a shape recessed with respect to the first tether portion.