Transition Zone Termination in Superconformal Electrodeposition
Solution Overview
Problem
Current methods for forming superconformal fillings in recesses of substrates often result in voids and seams, especially in high aspect ratio features, due to inadequate control over metal deposition rates and distributions.
Innovation Solution
A process involving electrodepositing metal using a composition with a suppressor to control deposition rates, bifurcating the recess into active and passive regions, and progressively moving a transition zone to ensure void-free, seam-free filling by depositing metal only in the active region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrodeposition is used to fill recesses, then metal deposition occurs uniformly across the surface, but voids and seams form in high aspect ratio features due to inadequate control over deposition rates
Solution Approach 1:
The patent applies local quality by creating distinct active and passive regions on the electrode surface through potentiodynamic control. The suppressor additive adsorbs preferentially on certain surface areas, creating location-dependent deposition behavior where metal deposits only in active regions while passive regions remain covered by suppressor, enabling controlled bottom-up filling without voids
Solution Approach 2:
The patent implements dynamics by using time-varying potential waveforms (triangular, square, or sinusoidal) to dynamically shift the boundary between active and passive regions during deposition. This dynamic control allows the deposition pattern to evolve over time, progressing from bottom to top of recesses while maintaining void-free filling
2Manufacturing precision
If suppressor additives are used to control deposition, then metal deposition is restricted to active regions, but the process complexity increases due to potentiodynamic or galvanodynamic control requirements
Solution Approach 1:
The patent applies parameter changes by utilizing suppressor additives that respond to electrochemical potential to modify deposition behavior. The suppressor concentration, type, and electrochemical properties are optimized to achieve the desired active-passive region bifurcation at practical potential ranges, simplifying the overall process control
Solution Approach 2:
The suppressor additive acts as an intermediary between the electrochemical potential and metal deposition. It mediates the deposition process by adsorbing on the electrode surface and selectively blocking active sites, translating potential changes into controlled spatial deposition patterns without requiring direct complex control mechanisms
3Productivity
If metal deposition is accelerated to increase productivity, then filling speed improves, but void formation increases due to loss of control over deposition distribution
Solution Approach 1:
The patent implements periodic action by using cyclic potential waveforms (triangular, square, or sinusoidal) that periodically vary the potential between anodic and cathodic extremes. This periodic variation continuously regenerates the active-passive region pattern, allowing sustained high-rate deposition while maintaining controlled distribution and preventing void formation
Solution Approach 2:
The patent ensures continuity of useful action by maintaining suppressor adsorption throughout the deposition process. The suppressor remains adsorbed on passive regions continuously, ensuring that even at accelerated deposition rates, metal deposits only in controlled active regions, maintaining both speed and precision
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 process achieves void-free and seam-free superconformal fillings in recesses, including high aspect ratio features, by selectively depositing metal within the active region, enhancing the filling efficiency and quality.
Implementation Method 1
a suppressor disposed in the solvent
Implementation Method 2
reducing the metal ions to form metal and depositing the metal in the active metal deposition region
Implementation Method 3
reducing the metal ions to form metal
Data Source
AI summary
Forming a transition zone terminated superconformal filling in a recess includes: providing an electrodeposition composition including: a metal electrolyte including a plurality of metal ions, solvent, and suppressor; providing the article including: a field surface and the recess that includes a distal position and a proximate position; exposing the recess to the electrodeposition composition; potentiodynamically controlling an electric potential of the recess with a potential wave form; bifurcating the recess into an active metal deposition region and a passive region; forming a transition zone; decreasing the electric potential of the recess by the potential wave form; progressively moving the transition zone closer to the field surface and away from the distal position; and reducing the metal ions and depositing the metal in the active metal deposition region and not in the passive region to form the transition zone terminated superconformal filling in the recess of the substrate.