Plating Method Using Conductive Liquid for Via Filling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plating methods struggle to fill vias on semiconductor wafers with plating film due to the plating film blocking the entrance of the via as it grows in the trench, leading to incomplete filling of the via with the plating film.
Innovation Solution
A plating method involving a plating apparatus that holds a substrate, supplies a plating liquid, and applies a voltage between the substrate and a conductive liquid, which is different from the plating liquid, to selectively form the plating film within the via by using a conductive liquid with a lower specific gravity to push out the plating liquid and ensure it remains inside the via.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plating liquid is supplied onto the substrate and voltage is applied to form plating film, then plating film is formed on the substrate surface, but the plating film blocks the via entrance preventing complete filling of the via
Solution Approach 1:
The patent segments the liquid supply process into two distinct stages: first supplying plating liquid to fill the via, then supplying conductive liquid to push out excess plating liquid from the via entrance. This segmentation allows the plating film to form completely within the via without blocking the entrance, as the conductive liquid removes excess material from the surface.
Solution Approach 2:
The patent introduces conductive liquid as an intermediary substance that mediates between the plating liquid and the substrate surface. The conductive liquid pushes out excess plating liquid from the via entrance while allowing plating film formation to continue within the via, thus preventing entrance blocking while maintaining filling completeness.
2Manufacturing precision
If plating liquid is supplied to fill the via, then via filling is achieved, but excess plating liquid remains on the substrate surface causing contamination
Solution Approach 1:
The conductive liquid acts as an intermediary that selectively removes excess plating liquid from the substrate surface while preserving the plating liquid within the via. This intermediary substance pushes out the excess plating liquid through capillary action and surface tension effects, preventing contamination without affecting the filling process.
Solution Approach 2:
The patent applies local quality by using conductive liquid that specifically targets and removes excess plating liquid from the via entrance and surrounding surface areas, while leaving the plating liquid undisturbed within the via structure. This localized action ensures contamination is removed only from affected areas.
3Reliability
If conventional plating method is used, then process simplicity is maintained, but via filling reliability is poor
Solution Approach 1:
The patent segments the liquid supply process into distinct steps: supplying plating liquid, supplying conductive liquid, and controlling their interaction. This segmentation improves via filling reliability by ensuring complete via filling while preventing entrance blocking, despite increasing process complexity.
Solution Approach 2:
The patent changes the parameters of the liquid supply process by introducing a second liquid (conductive liquid) with different properties than the plating liquid. This parameter change enables reliable via filling by controlling the interaction between the two liquids, where the conductive liquid pushes out excess plating liquid while allowing film formation to proceed.
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 successfully fills the via with the plating film without blocking the entrance, ensuring reliable and selective formation of the plating film within the via, even after multiple cycles, while minimizing contamination and unintended reactions.
Implementation Method 1
supplying a conductive liquid, which is different from the plating liquid supplied on the substrate, onto the plating liquid
Implementation Method 2
applying a voltage between the substrate and the conductive liquid
Data Source
AI summary
A plating method includes holding a substrate, supplying a plating liquid L1, supplying a conductive liquid L2 and applying a voltage. In the holding of the substrate, the substrate is held. In the supplying of the plating liquid L1, the plating liquid L1 is supplied onto the held substrate. In the supplying of the conductive liquid L2, the conductive liquid L2, which is different from the plating liquid L1 supplied on the substrate, is supplied onto the plating liquid L1. In the applying of the voltage, the voltage is applied between the substrate and the conductive liquid L2.