Laminar Flow Etching Device for Copper Uniformity
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Solution Overview
Problem
Current wet etching technologies for copper in the semiconductor industry suffer from poor uniformity due to inadequate control over flow dynamics, making them unsuitable for precise copper structuring in semiconductor devices.
Innovation Solution
An etching device is designed with a process chamber that provides a laminar flow of etchant and a workpiece handler to move the wafer through this flow along a predefined track, ensuring controlled and uniform diffusion of the etchant over the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wet etching tools (tank tool or spray tool) are used for copper etching, then the etching process can be carried out, but the uniformity of etching is poor due to inadequate control over flow dynamics
Solution Approach 1:
The patent implements a dynamic flow control system where the etchant delivery system can adjust flow rates and patterns during the etching process. The system transitions from static flow delivery to dynamic control, allowing real-time optimization of etchant distribution across the wafer surface, thereby improving etching uniformity while managing system complexity through controlled adaptability.
Solution Approach 2:
The patent changes the flow dynamics parameters of the etchant delivery system, specifically controlling Reynolds number to achieve laminar flow conditions. By adjusting flow rate, viscosity, and channel dimensions to maintain laminar flow (Re < 2000), the system achieves predictable and uniform etchant distribution across the wafer, directly improving etching precision without requiring overly complex equipment.
2Manufacturing precision
If the etchant flow rate is increased to improve uniformity, then better coverage is achieved, but flow dynamics become turbulent and uniformity deteriorates
Solution Approach 1:
The patent identifies and controls the Reynolds number as the critical parameter governing flow regime. By maintaining flow conditions where Re < 2000, the system ensures laminar flow regardless of etchant flow rate. This parameter control allows the system to achieve both high flow rates for good coverage and uniform distribution, resolving the contradiction between speed and uniformity.
Solution Approach 2:
The patent implements flow monitoring and control mechanisms that provide feedback on actual flow conditions. Sensors detect flow rate and turbulence levels, and the control system adjusts delivery parameters to maintain laminar flow conditions. This closed-loop control ensures uniform etchant distribution is maintained even at higher flow rates, eliminating the trade-off between speed and uniformity.
3Manufacturing precision
If batch tank processing is used for simplicity, then operation is easier, but flow dynamics cannot be controlled and uniformity is poor
Solution Approach 1:
The patent segments the etchant delivery system into multiple controlled zones with independent flow control. Instead of a single batch tank with uniform flow, the system divides etchant delivery into separate channels or regions, each with controllable flow rates. This segmentation enables precise control over etchant distribution across different areas of the wafer, achieving uniform etching while maintaining operational simplicity through modular control.
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 achieves highly uniform and controlled copper etching, addressing the limitations of existing technologies by maintaining consistent etchant distribution and improving etching precision.
Implementation Method 1
a structure configured to provide a laminar flow of the etchant
Implementation Method 2
a workpiece handler configured to move a workpiece through the laminar flow of the etchant along a predefined track
Implementation Method 3
using a copper wet etching chemistry, the wet etching chemistry being a chemical etchant
Data Source
AI summary
An etching device is provided, the etching device including a process chamber including an etchant, a structure configured to provide a laminar flow of the etchant, and a workpiece handler configured to move a workpiece through the laminar flow of the etchant along a predefined track.