Electroplating Paddle Motion for Uniform Copper Height
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Solution Overview
Problem
Current electroplating processes face challenges in achieving uniformity of copper bumps on semiconductor chips due to uneven stirring, leading to inconsistent electroplating heights and reduced production capacity.
Innovation Solution
An electroplating apparatus with a controller and driving mechanism that moves multiple parallel paddles in a controlled manner to ensure each point on the substrate is blocked for an equal time, optimizing the movement pattern to distribute the electric field evenly and enhance mass transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If ordinary paddles are used to stir the electroplating solution, then mass transfer is enhanced, but the substrate surface is blocked unevenly causing inconsistent electroplating height
Solution Approach 1:
The paddle assembly transitions from static or simple reciprocating motion to a dynamic multi-stage movement pattern including forward motion, backward motion, and lateral displacement. This dynamic positioning ensures that different regions of the substrate surface are blocked by paddles for equal cumulative time, achieving uniform electroplating height while maintaining enhanced mass transfer through continuous stirring action.
2Ease of operation
If cup plating is used instead of rack plating, then process controllability is improved, but production capacity is reduced due to one cup per substrate
Solution Approach 1:
The electroplating apparatus divides the substrate into multiple regions and uses multiple paddles to independently control electroplating in different zones. This segmentation allows simultaneous processing of multiple substrates in parallel while maintaining the controllable, uniform electroplating characteristics of cup plating, thereby increasing production capacity without sacrificing process quality.
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 achieves consistent electroplating heights across the substrate, improving the uniformity and quality of copper interconnections, and enhancing the production capacity by ensuring each point receives an equal amount of electricity.
Implementation Method 1
a paddle assembly can be installed in the electroplating apparatus, which includes multiple paddles parallel to the substrate surface. The paddles reciprocate to stir the electroplating solution, fully supplying metal ions and electroplating additives to the substrate surface.
Implementation Method 2
Electroplating is the primary process for completing copper interconnections.
Data Source
AI summary
Disclosed in one embodiment of the present invention is an electroplating apparatus and an electroplating method. The electroplating apparatus comprises a plurality of paddles arranged in parallel. The paddles move in a direction parallel to a substrate, and are used to stir electroplating solution. Within one cycle, the paddles perform reciprocating motion at a set stroke, and the turning points of the reciprocating motion are related to the width of the paddles and the narrowest width of a gap between adjacent paddles. According to the present invention, by designing the size and movement mode of the paddles, the accumulated time in which each corresponding point on the substrate is blocked by the paddles is equal, so that the received quantity of electricity is equal, and thus the consistency of an electroplating height is further improved.