Bidirectional Substrate Rotation for Uniform Electroplating Thickness
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Solution Overview
Problem
Existing electroplating apparatuses face challenges in achieving uniform plating film-thickness due to the trade-off between shielding specific substrate portions and maintaining stirring strength of the plating solution, as reducing rotation speed to extend shielding time compromises solution stirring.
Innovation Solution
A plating apparatus with a substrate holder that rotates in multiple directions and a shielding mechanism that moves a shielding member based on rotation angle to selectively shield specific substrate portions, enhancing stirring strength and film-thickness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the rotation speed of the substrate holder is decreased to extend the shielding time of a specific portion of the substrate, then the shielding duration is improved, but the stirring strength of the plating solution is reduced, making it difficult to achieve uniform plating film thickness
Solution Approach 1:
The substrate holder is configured to rotate in both forward and reverse directions dynamically. During plating, the holder rotates in a first direction, then reverses to a second direction, creating a reciprocating rotation pattern. This dynamic bidirectional rotation allows the system to maintain higher average rotation speeds for improved stirring while still providing adequate shielding duration for specific substrate portions when the shielding member is positioned appropriately.
Solution Approach 2:
The substrate holder performs periodic forward and reverse rotations during the plating process. This periodic reciprocating motion creates multiple rotation cycles within the plating time, ensuring that specific substrate portions receive adequate shielding exposure while the overall stirring action remains strong and uniform throughout the plating solution.
2Productivity
If the rotation speed of the substrate holder is increased to enhance the stirring strength of the plating solution, then the stirring strength is improved, but the shielding time of a specific portion of the substrate is reduced, making it difficult to control the plating film thickness
Solution Approach 1:
The system uses dynamic bidirectional rotation where the substrate holder rotates forward and then reverses direction. This creates multiple rotation cycles that increase the frequency of substrate portions passing under the shielding member, allowing for precise control of shielding duration even at higher rotation speeds. The reciprocating motion ensures adequate stirring strength while maintaining control over shielding exposure time.
3Manufacturing precision
If a shielding member is used to shield a specific portion of the substrate, then the control over plating film thickness is improved, but the stirring strength of the plating solution is reduced due to the need to decrease rotation speed
Solution Approach 1:
The substrate holder performs reciprocating rotation in forward and reverse directions, creating multiple rotation cycles during plating. This dynamic rotation pattern allows the system to maintain high rotation speeds for strong stirring while the shielding member selectively shields specific substrate portions during appropriate phases of the rotation cycle, achieving both good stirring strength and precise film thickness 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
The apparatus achieves controlled electric field shielding and improved stirring, resulting in uniform plating film-thickness by dynamically adjusting the shielding mechanism with the substrate holder's rotation.
Implementation Method 1
applies a voltage between the substrate and an anode, thereby depositing a conductive film on a surface of the substrate
Implementation Method 2
a voltage between the substrate and an anode is applied
Implementation Method 3
enhancing a stirring strength of a plating solution housed in a plating tank
Data Source
AI summary
A specific portion of a substrate is allowed to be shielded at a desired timing, and making a plating film-thickness uniform is improved.A plating module includes: a plating tank 410 for housing a plating solution; an anode 430 disposed in the plating tank410; a substrate holder 440 for holding a substrate Wf with a surface to be plated Wf-a facing downward; a rotation mechanism 447 configured to rotate the substrate holder 440 in a first direction and a second direction opposite to the first direction; and a shielding mechanism 485 configured to move a shielding member 481 into between the anode 430 and the substrate Wf depending on a rotation angle of the substrate holder 440.