Multi-Electrode Wafer Plating for Uniform Height Control
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Solution Overview
Problem
In semiconductor manufacturing, existing plating apparatuses face challenges in achieving uniform plating heights and reducing product yield due to non-uniform current density and the need for costly modifications when handling wafers of different sizes or notch shapes, leading to uneven plating films and increased costs.
Innovation Solution
A plating apparatus with multiple electrodes, including a main electrode and at least two second electrodes, allows for independent or joint control of electric fields to accommodate wafers of varying sizes and notch shapes, using power interfaces and diffusion plates with tailored perforations to manage electric and flow fields effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single electrode is used for plating, then the device structure is simple, but the plating height uniformity deteriorates due to terminal effect and non-uniform current density
Solution Approach 1:
The single electrode is divided into multiple electrodes (first electrode, second electrode, third electrode) arranged at different positions. Each electrode independently generates an electric field in its corresponding area, allowing localized control of current density to achieve uniform plating height across the entire wafer surface.
2Adaptability or versatility
If the plating chamber design is modified to accommodate different wafer sizes or notch shapes, then the adaptability improves, but the device complexity and cost increase
Solution Approach 1:
The system achieves adaptability through dynamic control of electrode configurations rather than physical modification of the chamber. By adjusting which electrodes are activated and their respective power levels, the same plating chamber can accommodate different wafer sizes and notch shapes without structural changes.
Solution Approach 2:
The multiple electrodes serve multiple functions: they can be selectively activated to match different wafer sizes, accommodate various notch shapes, and maintain plating uniformity across different configurations. This universal design eliminates the need for dedicated chamber modifications for each wafer type.
3Manufacturing precision
If the electric field intensity is increased at the non-plated area to reduce plating height, then the plating height uniformity improves, but the current density distribution becomes non-uniform
Solution Approach 1:
Each electrode is assigned a specific control region on the wafer surface. The control unit independently adjusts the electric field intensity in each region, allowing localized modification of plating characteristics at non-plated areas (notches) while maintaining appropriate current density distribution across the entire wafer through coordinated control of all electrodes.
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 solution enables uniform plating heights on wafers of different sizes or shapes without requiring whole chamber modifications, reducing costs and improving plating uniformity by controlling electric field intensities and flow fields.
Implementation Method 1
an electroplating process generally uses wafers as substrates to be plated and, metal layers or metal wires are formed in designated areas of the substrates by employing the electroplating process
Implementation Method 2
metal ions in the electrolyte are deposited on the surface of the wafer under the effect of an electric field
Data Source
AI summary
The present invention discloses a plating apparatus. The plating apparatus comprises a multiple electrodes. The multiple electrodes include a main electrode and at least two second electrodes. The main electrode and the at least two second electrodes respectively generate an electric field in a corresponding area on the surface of a wafer. The main electrode and the at least two second electrodes respectively have a control interface. By selecting the combination of the control relationship between each second electrode and the main electrode, the wafers with different sizes or different notch shapes are plated, and the control relationship is independent control or joint control. The plating apparatus of the present invention can plate wafers with different sizes or different notch shapes without replacing the whole plating chamber.