Plating Apparatus Current Density Correction for Semiconductor Recesses
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Solution Overview
Problem
Existing semiconductor device fabrication methods face challenges in achieving uniform plating of electro-conductive films in recesses due to variations in interconnect patterns, leading to excessive film growth or insufficient filling, resulting in inefficiencies and increased costs.
Innovation Solution
A method and apparatus that correct the current density based on the ratio of effective surface area to total surface area, including the area of side walls of recesses, to ensure consistent plating performance across different pattern densities, allowing for improved bottom-up performance and controlled film thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a predetermined reference current density is used for plating, then the plating process is simple and fast, but the film thickness becomes non-uniform when recesses are present on the substrate surface
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different surface regions. It separates the substrate surface into regions with recesses and regions without recesses, calculating current density separately for each. The side wall area of recesses is explicitly included in the effective surface area calculation, ensuring that areas with different topographies receive appropriately adjusted current densities to achieve uniform film thickness across the entire substrate.
2Manufacturing precision
If the plating process is optimized for substrates with many fine patterns, then filling of fine recesses improves, but processing time increases and throughput decreases
Solution Approach 1:
The patent applies preliminary action by calculating the effective surface area and determining the appropriate current density before the plating process begins. The side wall area of recesses is pre-calculated and incorporated into the effective surface area determination. This preliminary calculation allows the plating process to proceed with optimized parameters from the start, achieving good filling of fine patterns without requiring extended processing time or multiple plating 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
This approach enables uniform film formation and improved throughput by maintaining a constant current density, enhancing the properties of the plated film and reducing the time required for subsequent processing steps.
Implementation Method 1
a first plating process allowing current having a first current density to flow using as an electrode a seed film formed on the surface of an insulating film and in openings, so as to deposit an electro-conductive material in the openings by the plating process
Data Source
AI summary
A method of fabricating a semiconductor device of the invention includes a plating process of filling a plurality of recesses provided to an insulating film formed on a substrate with an electro-conductive material, wherein the plating process includes a process step (S104) of performing the plating with a first current density which was obtained by correcting a predetermined first reference current density based on ratio of surface area Sr=S1/S2 of a first surface area S1 over the entire surface of the substrate which includes the area of side walls of the plurality of recesses over the entire surface of the semiconductor substrate, and a second surface area S2 over the entire surface of the substrate which does not include the area of side walls of the plurality of recesses, when fine recesses not larger than a predetermined width, out of all of the plurality of recesses, are filled with the electro-conductive material.