Conductive Oxide Interface Layer for Adhesive-Free Direct Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor and optoelectronic device bonding methods rely on adhesives, which result in weak connections that can be reversed by reheating, whereas direct bonding techniques form strong covalent bonds without adhesives, enabling robust mechanical and electrical connections at room temperature without external pressure.
Innovation Solution
The use of electrically conductive oxide materials as an interface layer between substrates with conductive and insulative portions, allowing direct bonding of semiconductor elements without adhesives, utilizing techniques like hybrid bonding and direct metal-to-metal connections that interdiffuse and form grain growth across the bonding interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive bonding is used to join substrates, then the bonding process is simple and can be performed at low temperatures, but the resulting connections are weak and can be reversed by reheating
Solution Approach 1:
The patent removes the adhesive layer from the bonding interface, achieving direct substrate-to-substrate bonding. This extraction of the adhesive eliminates the weakness and reversibility associated with adhesive bonds, while the direct bonding process maintains simplicity through direct contact and covalent bond formation between substrates
Solution Approach 2:
The patent employs hybrid bonding that combines conductive material regions for electrical bonding with non-conductive field regions for mechanical bonding. This composite approach creates strong, irreversible connections by utilizing different bonding mechanisms in different regions of the interface
2Reliability
If direct bonding without adhesives is used, then strong covalent bonds are formed, but the process requires precise surface preparation and control
Solution Approach 1:
The patent applies different material properties to different regions of the bonding interface: conductive materials are used in contact regions for electrical bonding, while non-conductive materials are used in field regions for mechanical bonding. This local differentiation allows each region to be optimized for its specific function, reducing the overall precision requirements compared to uniform direct bonding
3Reliability
If conductive pads are directly bonded to conductive pads, then electrical connection is achieved, but thermal expansion mismatch and stress can cause bonding failures
Solution Approach 1:
The bonding interface is segmented into distinct conductive contact regions and non-conductive field regions. The non-conductive field regions act as stress-absorbing zones that accommodate thermal expansion mismatch and mechanical stress, protecting the conductive pad bonds from failure while maintaining electrical connectivity in the contact regions
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 method achieves strong, stable connections between semiconductor and optoelectronic devices, enabling high-density interconnects and robust mechanical and electrical bonds without the need for adhesives, with the potential for lower processing temperatures and simplified manufacturing.
Implementation Method 1
utilizing techniques like hybrid bonding and direct metal-to-metal connections that interdiffuse and form grain growth across the bonding interface
Implementation Method 2
utilizing techniques like hybrid bonding and direct metal-to-metal connections that interdiffuse and form grain growth across the bonding interface
Implementation Method 3
The at least one electrically conductive oxide material comprises at least one first region between and in electrical communication with the at least one electrically conductive first portion and the at least one electrically conductive third portion
Data Source
AI summary
A structure includes a first substrate including a first layer having at least one electrically conductive first portion and at least one electrically insulative second portion and a second substrate including a second layer having at least one electrically conductive third portion and at least one electrically insulative fourth portion. The structure further includes an interface layer having at least one electrically conductive oxide material between the first layer and the second layer. The at least one electrically conductive oxide material includes at least one first region between and in electrical communication with the at least one electrically conductive first portion and the at least one electrically conductive third portion, and at least one second region between the at least one electrically insulative second portion and the at least one electrically insulative fourth portion.