Isolated Seed Layer Plating Using a Barrier Layer Current Path
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Solution Overview
Problem
In semiconductor processing, traditional electrochemical deposition methods require post-plating resist removal, which slows down throughput and reduces yields, as they necessitate patterning a continuous seed layer and subsequent removal of un plated areas.
Innovation Solution
The method involves depositing a barrier layer on the substrate to form isolated seed layer areas, which are then electrochemically plated, eliminating the need for resist removal by using the barrier layer as a current path and preventing unwanted deposition through oxidation or descum processes, allowing for selective deposition and patterning without resist.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a continuous seed layer is patterned with resist and plated, then metal deposition can be controlled on specific areas, but post-plating resist removal is required which slows throughput and reduces yields
Solution Approach 1:
The patent extracts and removes the resist material from the process entirely. Instead of using resist to define patterns, the seed layer itself is patterned through selective etching to create isolated islands that serve as plating sites. This eliminates the need for post-plating resist removal and associated cleanup steps, directly resolving the throughput bottleneck while maintaining pattern definition precision through controlled etching processes.
Solution Approach 2:
The patent performs preliminary patterning of the seed layer before plating by selectively etching away portions of the seed layer to create isolated islands. This preliminary action defines the exact areas where metal deposition will occur, eliminating the need for subsequent resist removal steps and enabling direct plating on the pre-defined patterns, thus improving throughput without sacrificing precision.
2Manufacturing precision
If resist is used to mask areas during plating, then selective deposition is achieved, but additional process steps for resist application and removal increase process complexity
Solution Approach 1:
The patent removes the resist component from the process entirely. Selective deposition control is achieved through direct patterning of the seed layer via selective etching, which creates isolated islands that inherently define where plating will occur. This eliminates resist application, patterning, and removal steps, significantly reducing process complexity while maintaining precise selective deposition control.
Solution Approach 2:
The seed layer serves a dual function: it provides both the conductive base for plating and the pattern definition template. By selectively etching the seed layer to create isolated islands, the system uses the seed layer itself to define the deposition pattern, eliminating the need for separate resist materials and their associated processing steps, thereby reducing overall process complexity.
3Reliability
If a conformal seed layer connects all exposed areas together, then electrical continuity is maintained, but it prevents isolation of specific plating areas and requires resist masking
Solution Approach 1:
The patent segments the continuous seed layer into isolated islands through selective etching. Each island represents a discrete plating area that is electrically isolated from others during the plating process. This segmentation enables precise control over which areas receive metal deposition while maintaining the reliability of electrical continuity within each isolated island, as each island remains a complete conductive path from top to bottom.
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 enhances throughput by eliminating the need for post-plating resist removal, enabling high-quality, isolated metal deposition with improved uniformity and resolution, suitable for various applications including via filling and hybrid bonding, while reducing DRAM stack heights and increasing conductivity.
Implementation Method 1
the barrier layer provides adhesion for a seed layer material and inhibits migration of the seed layer material
Implementation Method 2
depositing the metal material on the at least one isolated seed layer area using an electrochemical deposition process
Implementation Method 3
performing an oxygen-based descum process after etching the seed layer to oxidize the at least one exposed portion of the barrier layer to inhibit electrochemical deposition on the barrier layer
Data Source
AI summary
A method of depositing a metal material on an isolated seed layer uses a barrier layer as a conductive path for plating. The method may include depositing a barrier layer on a substrate wherein the barrier layer provides adhesion for seed layer material and inhibits migration of the seed layer material, forming at least one isolated seed layer area on the barrier layer on the substrate, and depositing the metal material on the at least one isolated seed layer area using an electrochemical deposition process wherein the barrier layer provides a current path to deposit the metal material on the at least one isolated seed layer area.