Bond Pad Passivation Material for Corrosion Resistance
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Solution Overview
Problem
Existing semiconductor fabrication processes expose bond pads to corrosive chemicals, leading to corrosion and degradation of electrical connections, particularly at scrub marks and irregular features, which can result in failure of the bond between conductive materials and bond pads.
Innovation Solution
A passivation material comprising aluminum oxide and silicon oxide is formed on bond pads using a chemical solution with specific ratios of tetramethylammonium hydroxide, ammonium persulfate, and silicon, which fills voids and crevices, providing a continuous barrier against corrosive chemicals and ensuring secure electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fabrication processes are used to expose bond pads for electrical connection, then electrical connectivity is achieved, but corrosion and degradation of bond pads occur due to exposure to corrosive chemicals
Solution Approach 1:
A passivation material layer is introduced as an intermediary between the bond pad and corrosive chemicals. This layer selectively protects the bond pad surface from corrosion while allowing electrical contact through controlled regions, thereby resolving the contradiction between maintaining electrical connectivity and preventing chemical corrosion
Solution Approach 2:
The passivation material creates an inert protective environment around the bond pad, shielding it from corrosive chemicals during fabrication processes. This inert barrier prevents harmful chemical interactions while preserving the electrical connection functionality
2Reliability
If bond pads are exposed to allow conductive material bonding, then electrical connection is established, but irregular surfaces and voids create susceptibility to corrosion
Solution Approach 1:
The passivation material is applied with spatially varying properties: it provides enhanced protection in regions with irregularities and voids where corrosion risk is highest, while maintaining appropriate conductivity in bonding regions. This local differentiation resolves the contradiction between bond strength and corrosion resistance on irregular surfaces
3Object-affected harmful factors
If passivation material is applied to protect bond pads, then corrosion resistance is improved, but electrical conductivity may be compromised
Solution Approach 1:
The passivation material's properties are precisely controlled through parameters such as thickness, composition ratios (e.g., aluminum oxide to silicon oxide), and deposition conditions. By optimizing these parameters, the material achieves the dual function of providing corrosion protection while maintaining sufficient electrical conductivity for reliable connections
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 passivation material effectively prevents corrosion, maintaining low resistance and secure bonds between conductive structures and bond pads, even at irregular surfaces, thereby enhancing the reliability and robustness of semiconductor device connections.
Implementation Method 1
A passivation material comprising aluminum oxide and silicon oxide is formed on bond pads using a chemical solution with specific ratios of tetramethylammonium hydroxide, ammonium persulfate, and silicon
Data Source
AI summary
Semiconductor devices having discretely located passivation material are disclosed herein. In one embodiment, a semiconductor device assembly can include a bond pad having a bonding surface with a process artifact. A passivation material can be positioned to at least partially fill a portion of the process artifact. A conductive structure can be positioned to extend across the bonding surface of the bond pad.