Substrate Seed Layer for Vertical Surface Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Forming a metal layer with improved thin-film and adhesion properties on substrates with vertical surfaces is challenging due to non-uniform etching processes, which can result in rough wall surfaces and under-etch issues, making it difficult to achieve uniformity and reliability in electrical connections.
Innovation Solution
A method involving the formation of a diffusion material layer on the substrate, followed by annealing to create a seed layer, and then depositing a metal layer with an adhesive layer to enhance adhesion, using materials like Au, Cu, Ag, or their alloys, and incorporating Ti, Cr, or Ni for improved adhesion properties, specifically through physical vapor deposition or chemical vapor deposition techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal layer is formed directly on an etched substrate with vertical surfaces, then the electrical connection is established, but the adhesion property and thin-film uniformity deteriorate due to rough wall surfaces and non-uniform etching
Solution Approach 1:
A seed layer is introduced as an intermediary between the etched substrate and the metal layer. This seed layer serves as a mediator that compensates for the roughness and non-uniformity of the etched vertical surfaces, enabling subsequent metal layer deposition with improved adhesion and uniformity despite the underlying surface defects
Solution Approach 2:
The seed layer is formed in advance before the metal layer deposition. This preliminary action prepares the surface by creating a uniform, adhesive base layer that pre-compensates for the rough etched surface, ensuring that the subsequent metal layer can be deposited uniformly without directly contacting the defective etched surface
2Manufacturing precision
If dry etching is used to achieve precise patterning, then the pattern precision is improved, but the wall surface roughness increases making metal layer formation difficult
Solution Approach 1:
The seed layer acts as an intermediary that decouples the pattern precision requirement from the adhesion requirement. It allows the use of dry etching for precise patterning while providing a separate, uniform surface for metal layer deposition, thus maintaining both pattern precision and adhesion property independently
3Productivity
If under-etch is formed in the etching process, then the etching speed is improved, but the wall surface uniformity deteriorates making uniform metal layer formation difficult
Solution Approach 1:
The seed layer serves as a compensating intermediary that masks the wall surface uniformity defects caused by under-etch. It provides a uniform deposition surface for the metal layer, allowing fast etching speeds to be used without sacrificing the uniformity of the final metal structure
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
This approach results in a substrate structure with enhanced adhesion and uniformity of the metal layer, reducing the likelihood of peeling and ensuring reliable electrical connections, suitable for terahertz devices and other applications requiring precise patterning.
Implementation Method 1
some of the diffusion material in the diffusion material layer may be diffused downward by annealing, toward the surface of the etched portion and the top surface of the substrate
Implementation Method 2
the diffusion material layer may be formed by depositing a metal using a physical vapor deposition (PVD) method or a chemical vapor deposition (CVD) method
Implementation Method 3
the diffusion material layer may be formed by depositing a metal using a physical vapor deposition (PVD) method or a chemical vapor deposition (CVD) method
Implementation Method 4
the process of annealing the diffusion material layer may be performed by heating the diffusion material layer at a temperature of about 300 to about 1000° C. under an atmosphere of vacuum, argon (Ar) or nitrogen (N2)
Data Source
AI summary
Provided are a substrate structure and method of forming the same. The method of forming the substrate structure may include etching a substrate to form an etched portion having a vertical surface, forming a diffusion material layer on the whole substrate or in part of the substrate; annealing the diffusion material layer to form a seed layer diffused downward toward the surface of the etched portion, and forming a metal layer on the seed layer. Accordingly, surface characteristics of the etched portion of the substrate may be enhanced by the seed layer, and therefore, a metal layer with improved adhesion and a uniform thickness may be formed on the vertical surface of the etched portion.