Segmented Surface Electrode Structure for Thermal Cycle Crack Control
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Solution Overview
Problem
Conventional semiconductor devices face issues with thermal cycle tolerability due to crack formation in surface electrodes, which can lead to electrical breakdown, even when the electrodes are thickened to mitigate this problem.
Innovation Solution
A semiconductor device design featuring a semiconductor substrate with a center electrode and an outer peripheral electrode, where the outer peripheral electrode includes a hole part passing through a second metal layer to reach a first metal layer, reducing the contact area and facilitating debonding at the interface, thereby suppressing vertical crack extension and enhancing thermal cycle tolerability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the surface electrode is thickened to prevent crack formation, then the thermal cycle tolerability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The outer peripheral electrode is segmented into two separate metal layers (first metal layer and second metal layer) with an interface between them. This segmentation allows the crack to be diverted along the horizontal interface between layers rather than propagating vertically through the entire electrode thickness, thereby maintaining thermal cycle tolerability without requiring excessive electrode thickness.
Solution Approach 2:
The crack propagation path is redirected from the vertical dimension (thickness direction) to the horizontal dimension (parallel to the substrate surface). By creating an interface between the first and second metal layers, the crack is forced to travel horizontally along the interface instead of vertically through the electrode, effectively changing the dimension of crack propagation.
2Reliability
If the surface electrode is thickened to secure thermal cycle tolerability, then the crack resistance is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The electrode is divided into multiple metal layers that can be fabricated separately and then stacked. This segmentation allows each layer to be manufactured with standard precision requirements, avoiding the need to manufacture a single thick electrode layer with extremely high precision. The interface between layers provides the crack diversion mechanism.
3Ease of manufacture
If the electrode structure is simplified, then the manufacturing ease is improved, but the thermal cycle tolerability deteriorates
Solution Approach 1:
The segmented metal layer structure provides a built-in crack diversion mechanism at the interface between the first and second metal layers. This segmentation is achieved through standard multi-layer fabrication processes, maintaining manufacturing ease while significantly improving thermal cycle tolerability by preventing vertical crack propagation.
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
The design effectively reduces the likelihood of vertical crack propagation, improving the semiconductor device's thermal cycle tolerability and extending its lifespan by allowing debonding to occur horizontally, thus preventing electrical breakdown.
Implementation Method 1
a non-electrolytic plating layer provided on the first main electrode not covered by the protection film
Data Source
AI summary
The present invention relates to a semiconductor device. The semiconductor device includes: a first main electrode provided on an active region; a second main electrode provided on an opposite side of the semiconductor substrate from the first main electrode; a protection film covering a terminal region; and a non-electrolytic plating layer provided on the first main electrode not covered by the protection film, the first main electrode includes a center electrode in a center part and an outer peripheral electrode provided along the center electrode to be separately from the center electrode, the protection film is provided to extend from the terminal region to an end edge portion of the outer peripheral electrode, the center electrode and the outer peripheral electrode include: a first metal layer; and a second metal layer provided on the first metal layer, and the outer peripheral electrode includes a hole part to reach the first metal layer.