Conductive Interconnect Bonding Without CMP Between Substrates
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Solution Overview
Problem
Conventional hybrid bonding processes require chemical mechanical planarization (CMP) and chemical vaporization deposition (CVD) treatments, which can introduce defects and impair the quality of substrate bonding, necessitating a more effective method for forming conductive structures between substrates.
Innovation Solution
A hybrid bonding process that eliminates the need for CMP by forming patterned base layers with through-holes, creating metallic contact structures, and using patterned polymer layers with descumming and plasma treatments for surface preparation, allowing for bonding based on thermal expansion characteristics of materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If CMP process is used to planarize substrate surfaces, then bonding surface flatness is improved, but metal dishing and oxide erosion occur that impair bonding quality
Solution Approach 1:
The patent removes the CMP process entirely from the hybrid bonding workflow. Instead of planarizing the substrate surface, the invention uses self-aligned through-holes in patterned base layers to expose underlying metallic contact structures, eliminating the source of metal dishing and oxide erosion while maintaining bonding precision through the through-hole alignment mechanism
Solution Approach 2:
The patent performs preliminary formation of through-holes in the patterned base layers before bonding, which pre-exposes the metallic contact structures. This preliminary action eliminates the need for subsequent CMP processing and ensures that the bonding surfaces are properly prepared without introducing the defects associated with mechanical planarization
2Manufacturing precision
If CMP and CVD treatments are used for surface preparation, then bonding surface quality is improved, but process complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the CMP and CVD treatment steps from the conventional hybrid bonding process. The bonding surface preparation is achieved through through-hole formation and exposure of pre-formed metallic contact structures, significantly reducing process complexity while maintaining bonding quality
Solution Approach 2:
The patent uses patterned base layers with through-holes as a disposable structure that simplifies the overall process. These base layers are formed with through-holes that directly expose the bonding surfaces, eliminating the need for expensive and complex CMP and CVD equipment and 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
This approach enables the formation of better conductive structures between substrates at a lower cost without introducing defects, improving the bonding quality and reducing the reliance on high-cost CMP treatments.
Implementation Method 1
passivating the front surfaces of the first and second metallic contact structures
Implementation Method 2
bonding based on thermal expansion characteristics of materials
Data Source
AI summary
A method for forming conductive structures between two substrates is disclosed. The method comprises: forming a first patterned base layer and a second patterned base layer on a first substrate and a second substrate, wherein the first and second patterned base layers comprise through-holes; forming first and second metallic contact structures in the through holes of the first and second patterned base layer, wherein both the first and second metallic contact structures have front surfaces that are higher than respective front surfaces of the first and second patterned base layers; forming a first and a second patterned polymer layer on the respective front surfaces of the first and second patterned base layer, wherein the first and second metallic contact structures are exposed from and higher than respective front surfaces of the first and second patterned polymer layer; passivating the front surfaces of the first and second metallic contact structures; bonding the front surfaces of the first and second metallic contact structures with each other; and bonding the front surfaces of the first and second patterned polymer layers with each other after the front surfaces of the first and second metallic contact structures are bonded with each other.