Wafer Electroplating Electrode Layout for Notch-Area Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor fabrication, existing electroplating processes face challenges in achieving uniform plating heights due to asymmetrical wafer arrangements, leading to higher plating rates near notches, which can result in reduced product yield and increased complexity in controlling rotation speeds to mitigate this issue.
Innovation Solution
An electroplating apparatus with multiple electrodes forming independent electric fields, allowing for precise control of electric field intensity and rotation speed to reduce power received by notches, ensuring consistent plating heights across the wafer surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a uniform electric field is generated by circular and annular electrodes, then the plating process can be completed well for symmetrical chip arrangements, but the plating height becomes non-uniform when non-plated areas (notches) are present on the wafer
Solution Approach 1:
The electrode structure is segmented into multiple independent electrodes (circular electrode, annular electrode, and additional electrodes positioned to cover notch areas). Each electrode can be independently controlled to generate electric fields in specific regions, allowing the system to adapt to wafers with non-plated areas while maintaining uniform plating height across plated regions.
Solution Approach 2:
Different regions of the wafer are subjected to different electric field intensities by controlling individual electrodes. The additional electrodes positioned to cover notch areas generate reduced electric field intensity in those specific regions, preventing excessive plating height at notch locations while maintaining normal plating in other areas.
2Manufacturing precision
If the wafer rotation speed is reduced when the notch is positioned under the electrode, then the plating rate at the notch area is lowered, but the acceleration and deceleration cause disturbance to the plating solution and positional deviation
Solution Approach 1:
The mechanical control method of varying wafer rotation speed is replaced with an electrical control method. Independent electrodes with controllable electric field intensities are used to directly regulate the plating rate at notch areas, eliminating the need for acceleration and deceleration of wafer rotation and thus avoiding plating solution disturbance and positional deviation.
3Manufacturing precision
If the wafer rotation speed is changed to control plating height, then the plating height can be adjusted, but the overall plating current density decreases which is not conducive to increasing output
Solution Approach 1:
The electrode structure is segmented into multiple independent electrodes (circular electrode, annular electrode, and additional electrodes positioned to cover notch areas). Each electrode can be independently controlled to generate electric fields in specific regions, allowing the system to adapt to wafers with non-plated areas while maintaining uniform plating height across plated regions.
Solution Approach 2:
Different regions of the wafer are subjected to different electric field intensities by controlling individual electrodes. The additional electrodes positioned to cover notch areas generate reduced electric field intensity in those specific regions, preventing excessive plating height at notch locations while maintaining normal plating in other areas.
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 provides more accurate and reliable control over plating heights, enhancing electroplating efficiency and reducing yield loss by directly managing electric field intensity rather than solely relying on rotation speed adjustments.
Implementation Method 1
a plurality of electrodes, the plurality of electrodes forming electric fields on the surface of the wafer
Implementation Method 2
Electroplating is achieved by means of electrochemical reaction
Data Source
AI summary
Embodiments of the present invention provide an electroplating apparatus for electroplating on a surface of a wafer, which comprising a plurality of electrodes, for forming electric fields on the surface of the wafer, an independent electric field is formed in a designated area, when a notch of the wafer is positioned within the designated area, a total amount of power received by the notch is reduced. Embodiments of the present invention also provide an electroplating method for electroplating on a surface of a wafer, the method controlling the plurality of electrodes to form electric fields on the surface of the wafer, an independent electric field is formed in a designated area, when a notch of the wafer is positioned within the designated area, a total amount of power received by the notch is reduced. The present invention is more accurate and reliable, the electroplating efficiency is also increased.