Composite Protective Coating for High-Selectivity Plasma Dicing
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Solution Overview
Problem
Current plasma etching techniques for separating semiconductor die from substrates suffer from low selectivity of etching between the substrate material and the mask material, particularly for thicker substrates, leading to inadequate protection and inefficiency in the dicing process.
Innovation Solution
A composite material coating with a matrix component, such as carbon-containing or polymer materials, and a filler component, including silicon-containing particles, is applied to the substrate surface, allowing selective removal of the coating from street areas to expose them for plasma etching while protecting device structures, thereby enhancing etching selectivity and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mask material is used for plasma etching of substrate material, then the substrate can be separated into individual die, but the selectivity of etching between substrate material and mask material is low, causing inadequate protection for thicker substrates
Solution Approach 1:
The patent applies a composite protective film comprising a first protective material layer (such as silicon oxide, silicon nitride, or silicon oxynitride) and a second protective material layer (such as boron nitride or diamond-like carbon). This multi-layer composite structure provides enhanced etching selectivity (greater than 100:1) compared to single-layer masks, allowing the substrate to be selectively etched while maintaining adequate protection for thicker substrates during plasma dicing processes.
2Productivity
If conventional mask materials are used for plasma etching, then the dicing process can be performed, but the etching selectivity is insufficient leading to substrate damage
Solution Approach 1:
The composite protective film with specific material combinations (first layer: silicon oxide/silicon nitride/silicon oxynitride; second layer: boron nitride/diamond-like carbon) achieves etching selectivity greater than 100:1. This high selectivity prevents substrate damage while maintaining efficient dicing productivity, as the protective layers resist plasma etching much more effectively than conventional single-layer masks.
Solution Approach 2:
The patent changes the material parameters and compositional structure of the protective film by using specific combinations of inorganic materials with different etching resistance properties. This parameter optimization enables the protective film to withstand plasma etching conditions without damaging the substrate, thereby eliminating substrate damage while preserving dicing efficiency.
3Ease of manufacture
If a single-layer protective coating is used, then the application process is simple, but the etching selectivity is insufficient for thicker substrates
Solution Approach 1:
While the coating application process remains relatively simple using standard deposition techniques, the patent employs a two-layer composite structure where the first layer (silicon oxide, silicon nitride, or silicon oxynitride) and second layer (boron nitride or diamond-like carbon) work synergistically. This composite approach achieves etching selectivity greater than 100:1, significantly improving upon single-layer coatings while maintaining ease of manufacture through established deposition processes.
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 improved protective coating achieves a higher selectivity of etching, greater than 100:1, allowing for precise separation of semiconductor die with reduced damage to the substrate and mask material, enhancing the plasma dicing process.
Implementation Method 1
The masked substrate is then processed using a reactive gas plasma which etches the substrate material exposed between the die
Data Source
AI summary
The present invention provides a method for an improved protective coating for plasma dicing a substrate. A work piece having a support film, a frame and the substrate, the substrate having a top surface and a bottom surface, the top surface of the substrate having a plurality of device structures and a plurality of street areas is provided. The work piece is formed by adhering the substrate to a support film and then mounting the substrate with the support film to a frame. A composite material coating having a matrix component and a filler component is applied to the top surface of the substrate. The filler component has a plurality of particles. The composite material coating is removed from at least one street area to expose the street area. The exposed street area is plasma etched. The composite material coating is removed from the top surface of the substrate.