Dielectric Bonding Layer Microwave Annealing to Reduce Warpage
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Solution Overview
Problem
Semiconductor elements often exhibit warpage, which prevents strong bonds and reduces electrical connectivity between opposing contact structures during direct bonding processes.
Innovation Solution
A method involving microwave annealing of a dielectric bonding layer on semiconductor elements to densify and stabilize the structure, followed by direct bonding without an adhesive, using techniques such as plasma deposition and activation to enhance bonding surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If semiconductor elements are directly bonded without adhesive, then manufacturing complexity is reduced and bonding strength is improved, but warpage prevents strong bonds and reduces electrical connectivity
Solution Approach 1:
The patent applies preliminary action by performing microwave annealing on the dielectric bonding layer before the direct bonding process. This pre-treatment densifies the dielectric material and stabilizes the semiconductor element structure, reducing warpage that would otherwise prevent strong bonds. The microwave annealing step prepares the bonding surfaces in advance, ensuring they are ready for successful direct bonding without adhesive.
Solution Approach 2:
The patent utilizes parameter changes by employing microwave radiation to alter the physical and chemical properties of the dielectric bonding layer. The microwave energy changes the density and structural parameters of the dielectric material, transforming it from a less dense state to a densified state that is more suitable for direct bonding. This parameter transformation enables the bonding process to overcome warpage issues.
2Reliability
If microwave annealing is applied to densify dielectric bonding layer, then bond strength is improved and warpage is reduced, but additional process steps are required
Solution Approach 1:
The patent replaces traditional thermal annealing processes with microwave annealing. Instead of using conventional heating methods that require extended time and higher temperatures, microwave radiation directly energizes the dielectric material molecules, achieving densification more efficiently. This substitution reduces the overall process time and temperature requirements, offsetting the added step complexity with improved process efficiency.
Solution Approach 2:
The microwave annealing process employs periodic action through controlled microwave radiation cycles. The dielectric bonding layer is exposed to microwave energy in controlled intervals, allowing for progressive densification without excessive heating. This periodic exposure pattern enables precise control over the annealing process, achieving reliable bonds while managing process complexity.
3Stability of the object's composition
If dielectric bonding layer is deposited at high temperature, then material quality is improved, but subsequent processing requires higher temperatures and warpage increases
Solution Approach 1:
The patent replaces conventional thermal processing with microwave processing for the annealing step. Instead of continuing to use high temperatures for subsequent processing, microwave radiation provides the necessary energy for densification at lower temperatures. This substitution allows the dielectric layer to maintain its high-quality composition from high-temperature deposition while avoiding the warpage issues that would result from additional high-temperature processing steps.
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 method effectively reduces warpage and enhances bond strength, enabling strong, adhesive-free connections between semiconductor elements, improving electrical connectivity and device yield.
Implementation Method 1
microwave annealing a dielectric bonding layer of a first element by exposing the dielectric bonding layer to microwave radiation
Implementation Method 2
microwave annealing a dielectric bonding layer of a first element by exposing the dielectric bonding layer to microwave radiation
Implementation Method 3
depositing the dielectric bonding layer comprises plasma depositing the dielectric bonding layer
Data Source
AI summary
Disclosed herein are methods for direct bonding. In some embodiments, the direct bonding method includes microwave annealing a dielectric bonding layer of a first element by exposing the dielectric bonding layer to microwave radiation and then directly bonding the dielectric bonding layer of the first element to a second element without an intervening adhesive. The bonding method also includes depositing the dielectric bonding layer on a semiconductor portion of the first element at a first temperature and microwave annealing the dielectric bonding layer at a second temperature lower than the first temperature.