Semiconductor Electrode Pad Structure to Suppress Metal Layer Peeling
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Solution Overview
Problem
The existing semiconductor devices face issues with metal layers cracking or peeling due to stress or impact, particularly in the electrode pad portion covered by an insulating film.
Innovation Solution
A semiconductor device design featuring a first electrode with an insulator annular shape overlapping its outer edge, a first metal layer covering the electrode and insulator, and a second metal layer laminated on the first, with specific edge configurations to prevent peeling, combined with a manufacturing method involving multiple etching steps to form these layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple metal layers are laminated over the electrode pad and insulator, then the electrical connectivity is improved, but the metal layers may crack or peel off due to stress or impact
Solution Approach 1:
The patent divides the metal layer structure into multiple segments (first metal layer, second metal layer, third metal layer) with each layer having a specific width and position. The first metal layer has width W1, the second has width W2, and the third has width W3, creating a stepped configuration that segments the stress distribution across layers rather than having a single continuous layer subjected to uniform stress.
Solution Approach 2:
The patent introduces a dimensional variation by positioning the outer peripheral edges of different metal layers at different distances from the electrode pad center. The first metal layer extends to distance D1, the second to D2, and the third to D3, creating a multi-level stepped structure in the radial dimension that distributes mechanical stress across different spatial zones.
2Area of stationary object
If the metal layers extend to the outer peripheral edge of the insulator, then the coverage area is maximized, but the stress concentration at the edge causes peeling
Solution Approach 1:
The patent applies local quality by creating different coverage extents for different metal layers. The first metal layer has the maximum coverage extending to distance D1, while the second and third metal layers have progressively smaller coverage areas extending to distances D2 and D3 respectively. This localized variation in coverage area prevents stress concentration at the outer edge while maintaining adequate coverage where needed.
Solution Approach 2:
The patent uses dimensional variation in the radial direction by positioning the outer peripheral edges of different metal layers at different distances from the electrode pad center (D1, D2, D3). This creates a stepped configuration where each layer terminates at a different radius, distributing the mechanical stress across multiple zones rather than concentrating it at a single outer edge.
Data Source
AI summary
A semiconductor device includes: a semiconductor element that includes an element main body having an element main surface and an element back surface facing opposite sides to each other in a thickness direction, and a first electrode arranged on the element main surface; an insulator that has an annular shape overlapping an outer peripheral edge of the first electrode when viewed in the thickness direction and is arranged over the first electrode and the element main surface; a first metal layer arranged over the first electrode and the insulator; and a second metal layer laminated on the first metal layer and overlapping both the first electrode and the insulator when viewed in the thickness direction.