Electroplating Substrate Holder Cleaning via High-Velocity Nozzle
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Solution Overview
Problem
The electroplating of tin-silver alloys onto semiconductor substrates is hindered by the buildup of spurious tin-silver deposits on the lipseal and cup bottom regions of electroplating devices, leading to processing difficulties and contamination, with current cleaning methods being inefficient and prone to errors.
Innovation Solution
A method and apparatus for cleaning the lipseal and cup bottom regions using a nozzle to dispense a stream of cleaning solution with a velocity of 5-40 meters/second, oriented at specific angles, to remove metal deposits, potentially with megasonic waves, and an automated system for determining when to perform cleaning operations based on substrate counts or electric charge transferred.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual wiping with nitric acid solution is used to clean metal deposits, then cleaning effectiveness is improved, but the risk of damaging the lipseal and operational errors increases
Solution Approach 1:
The patent replaces manual mechanical wiping with an automated spray system that uses pressurized cleaning solution to remove metal deposits. The spray apparatus delivers cleaning solution at controlled pressure and flow rates, eliminating the need for manual contact with the fragile lipseal region while maintaining effective cleaning of tin-silver deposits.
Solution Approach 2:
The cleaning system is integrated into the electroplating apparatus and performs automatic cleaning of the substrate holder between plating operations. The system self-regulates the cleaning process through programmed spray cycles, eliminating the need for operator intervention and reducing human error while consistently maintaining cleaning effectiveness.
2Reliability
If frequent cleaning operations are performed to prevent lipseal failure, then reliability is improved, but production time and productivity are reduced
Solution Approach 1:
The cleaning system operates periodically between electroplating batches rather than continuously or manually after each substrate. This periodic automated cleaning maintains lipseal reliability by removing accumulating metal deposits while minimizing interruptions to high-volume production cycles.
Solution Approach 2:
The system performs preliminary cleaning of the substrate holder before the next plating operation begins, preventing deposit accumulation that could lead to lipseal failure. By proactively maintaining cleanliness during idle periods between production runs, the system ensures reliability without slowing down overall productivity.
3Device complexity
If manual cleaning techniques are used, then device complexity is minimized, but cleaning precision and consistency deteriorate
Solution Approach 1:
The patent replaces imprecise manual wiping with an automated spray system that delivers cleaning solution with controlled pressure, flow rate, and distribution patterns. This mechanical substitution provides consistent, repeatable cleaning results across multiple operations while adding manageable complexity through standardized spray mechanisms.
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
Effectively removes spurious metal deposits, reducing contamination and preventing catastrophic failures, while minimizing the use of corrosive chemicals and avoiding damage to the electroplating apparatus, thereby enhancing the efficiency and reliability of the electroplating process.
Implementation Method 1
dispensing a stream of cleaning solution having a fluid velocity between about 5 and 40 meters/second from the first nozzle such that the stream of cleaning solution contacts the inner circular edge of the lipseal and/or cup bottom
Implementation Method 2
the stream of cleaning solution contacts the inner circular edge of the lipseal and/or cup bottom while they are rotating in the first rotational direction, removing metal deposits
Data Source
AI summary
Disclosed herein are methods of cleaning a lipseal and/or cup bottom of an electroplating device by removing metal deposits accumulated in prior electroplating operations. The methods may include orienting a nozzle such that it is pointed substantially at the inner circular edge of the lipseal and/or cup bottom, and dispensing a stream of cleaning solution from the nozzle such that the stream contacts the inner circular edge of the lipseal and/or cup bottom while they are being rotated, removing metal deposits. In some embodiments, the stream has a velocity component against the rotational direction of the lipseal and/or cup bottom. In some embodiments, the deposits may include a tin/silver alloy. Also disclosed herein are cleaning apparatuses for mounting in electroplating devices and for removing electroplated metal deposits from their lipseals and/or cup bottoms. In some embodiments, the cleaning apparatuses may include a jet nozzle.