Metal Pad Protective Layer Against Halogen Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing redistribution layer (RDL) technologies in semiconductor integrated circuits face issues with corrosion of metal contact pads due to the release of halogenic components from polyimide layers, which react with aluminum pads to form corrosive compounds, leading to increased resistance and device degradation.
Innovation Solution
A protective dielectric layer, such as silicon oxide or silicon nitride, is formed between the contact pad and the polyimide layer using plasma-enhanced chemical vapor deposition (PECVD) or atomic layer deposition (ALD), or by treating the contact pad with oxygen, nitrogen, or ammonia to create aluminum oxide or aluminum nitride, preventing halogenic ions from reaching the pad and causing corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If polyimide layers are used in RDL structures, then routing flexibility and bond connection dispersion are improved, but corrosion of metal contact pads occurs due to halogenic component release
Solution Approach 1:
A protective dielectric layer (silicon oxide or silicon nitride) is introduced as an intermediary barrier between the polyimide layer and the metal contact pad. This intermediate layer prevents direct contact between halogenic components released from the polyimide and the aluminum pad, thereby eliminating the corrosion mechanism while preserving the routing flexibility benefits of the polyimide structure.
Solution Approach 2:
The structure is segmented into distinct functional layers: the polyimide layer for routing flexibility, the protective dielectric layer for corrosion prevention, and the metal contact pad for electrical connection. This segmentation allows each layer to perform its specific function without interfering negatively with others, particularly isolating the metal pad from halogenic contamination.
2Manufacturing precision
If halogen-containing polymeric materials are used to improve patterning resolution, then photolithography performance is improved, but corrosion resistance of metal pads deteriorates
Solution Approach 1:
The protective dielectric layer serves as a mediator that allows the halogen-containing polymeric material to be used for improved patterning resolution while preventing the harmful byproducts (halogenic ions) from reaching and corroding the metal pad. The intermediary layer thus enables the beneficial photolithography performance while blocking the harmful corrosion effect.
Solution Approach 2:
The halogenic components that would normally cause corrosion are converted into a beneficial situation by using the protective dielectric layer to contain them. The same polymeric materials that release halogenic ions are now used advantageously for high-resolution patterning, with the harmful ions being contained and redirected toward the protective layer rather than the metal pad.
3Reliability
If aluminum contact pads are used for electrical connection, then conductivity is improved, but susceptibility to halogen-induced corrosion increases
Solution Approach 1:
The protective dielectric layer acts as an intermediary barrier specifically protecting the aluminum contact pad from halogen corrosion while allowing the aluminum to maintain its excellent electrical conductivity properties. The intermediary layer blocks the corrosive interaction without interfering with the electrical function.
Solution Approach 2:
The protective dielectric layer creates an inert environment around the aluminum contact pad, preventing exposure to reactive halogenic species. This inert barrier allows the aluminum to function at its full conductive potential without degradation from chemical reactions with halogens.
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 protective dielectric layer effectively blocks fluorine or chlorine ions, preventing corrosion of the metal pads and maintaining device performance by ensuring the contact resistance remains low and stable.
Implementation Method 1
The protective dielectric layer effectively blocks fluorine or chlorine ions, preventing corrosion of the metal pads
Implementation Method 2
A protective dielectric layer, such as silicon oxide or silicon nitride, is formed between the contact pad and the polyimide layer using plasma-enhanced chemical vapor deposition (PECVD)
Implementation Method 3
A protective dielectric layer, such as silicon oxide or silicon nitride, is formed between the contact pad and the polyimide layer using plasma-enhanced chemical vapor deposition (PECVD) or atomic layer deposition (ALD)
Implementation Method 4
by treating the contact pad with oxygen, nitrogen, or ammonia to create aluminum oxide or aluminum nitride
Implementation Method 5
by treating the contact pad with oxygen, nitrogen, or ammonia to create aluminum oxide or aluminum nitride
Data Source
AI summary
Semiconductor devices, integrated circuits and methods of forming the same are provided. In one embodiment, a method includes depositing a first dielectric layer over a metal pad disposed over a workpiece, forming a first opening in the first dielectric layer to expose a portion of the metal pad, after the forming of the first opening, forming a second dielectric layer over the exposed portion of the metal pad, depositing a first polymeric material over the second dielectric layer, forming a second opening through the first polymeric material and the second dielectric layer to expose the metal pad, and forming a bump feature over the exposed metal pad.