Wafer Electroplating Auxiliary Electrode Control for Notch Uniformity
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Solution Overview
Problem
Existing wafer electroplating technologies suffer from non-uniform electroplating due to notches and flat edges on wafers, leading to uneven metal deposition and reduced reliability of semiconductor devices.
Innovation Solution
A device with an electroplating rate adjustment component, including auxiliary electrodes and a support ring structure, dynamically adjusts the electroplating rate near notches by diverting current through auxiliary electrodes and controlling their proximity to the wafer notch, using a magnetic levitation support ring for flexible movement and rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a uniform electric field is used for electroplating, then the electroplating process is simple, but the electroplating uniformity deteriorates due to notches and flat edges causing current density variations
Solution Approach 1:
The patent applies local quality by introducing auxiliary electrodes specifically at the notch locations of the wafer. These auxiliary electrodes are positioned only where needed (at notches) rather than uniformly across the entire wafer surface, creating localized current distribution adjustments. This resolves the contradiction by maintaining overall process simplicity while addressing specific local problems caused by notches and flat edges.
Solution Approach 2:
The auxiliary electrodes serve as intermediary elements between the main anode and the wafer surface. These intermediate electrodes divert current away from the notch regions, mediating the current distribution to achieve more uniform electroplating. The auxiliary electrodes act as mediators that translate the uniform electric field into a modified current distribution pattern that compensates for the geometric imperfections.
2Manufacturing precision
If auxiliary electrodes are added to adjust electroplating rate, then the electroplating uniformity improves, but the device complexity increases
Solution Approach 1:
The patent segments the electroplating system by adding separate auxiliary electrodes that are independently controllable. Each auxiliary electrode can be independently activated and controlled through switching devices, allowing segmented control of current distribution. This segmentation enables precise control of electroplating rate in specific regions without requiring complete redesign of the entire electroplating system.
Solution Approach 2:
The patent introduces dynamic control elements including switching devices and control modules that can dynamically adjust the operation of auxiliary electrodes. The system can transition between different operational states (auxiliary electrodes on/off) based on real-time requirements, enabling adaptive control of electroplating uniformity without permanent structural modifications to the core electroplating equipment.
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
Improves electroplating uniformity by controlling current distribution, enhancing wafer yield and production efficiency, and ensuring consistent metal deposition across the wafer surface.
Implementation Method 1
the auxiliary electrodes are connected to the negative pole of the power supply... establishing an electrical current path through the wafer and the electroplating solution to facilitate an electrochemical reaction
Implementation Method 2
using a magnetic levitation support ring for flexible movement and rotation
Implementation Method 3
Metal electroplating process is widely used... deposits metal on the surface of round wafers... facilitating an electrochemical reaction
Data Source
AI summary
A device, method, and equipment for improving the electroplating uniformity in wafer electroplating. The device includes an electroplating component and an electroplating rate adjustment component. The electroplating component includes an electroplating head, an electroplating tank, an anode metal and a power supply. The electroplating rate adjustment component includes an auxiliary electrode assembly, a switching device and a control module. The auxiliary electrode assembly consists of auxiliary electrodes, a circuit resistor assembly and a support ring structure. The auxiliary electrode is set on the support ring structure, and when the auxiliary electrode is connected to the circuit resistor assembly, the support ring body can be controlled to lift or rotate, bringing the auxiliary electrode closer to or farther from the wafer notch, thereby adjusting the electroplating rate at the notch.