Plating-Deplating Waveform Contact Cleaning for Substrate Electroplating
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Solution Overview
Problem
Current electroplating systems face challenges in efficiently removing non-metallic, non-conductive residual from contact pins, which leads to electrical contact degradation and increased defect rates, requiring manual chemical etching and hazardous chemicals, impacting tool availability and safety.
Innovation Solution
A plating-de-plating waveform with multiple cycles of varying voltage and current is applied between contact pins and a counter electrode to continuously remove residual, eliminating the need for manual chemical etching and hazardous chemicals, allowing for automated and efficient cleaning within the electroplating system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual chemical etching is used to remove residual from contact pins, then cleaning effectiveness is improved, but device complexity and safety hazards increase due to handling hazardous chemicals
Solution Approach 1:
The patent replaces chemical etching with an electrochemical de-plating process. Instead of using hazardous chemical reagents to remove residual metal from contact pins, the system applies controlled voltage pulses that generate electrochemical reactions in the plating bath, selectively dissolving residual metal through oxidation reactions at the anode (contact pin) without requiring external chemical etchants.
Solution Approach 2:
The plating bath serves dual purposes: it both deposits metal during normal operation and enables removal of residual metal during cleaning cycles. The same electrolyte solution that facilitates electroplating also provides the medium for electrochemical de-plating, eliminating the need for separate hazardous chemical cleaning agents.
2Reliability
If manual chemical etching is used to clean contact pins, then residual removal is improved, but productivity decreases due to reduced tool availability
Solution Approach 1:
The electrochemical de-plating process can be performed automatically in-situ within the electroplating system without removing contact pins or interrupting normal operations. The system applies voltage pulses during designated cleaning cycles, maintaining continuous operational capability and eliminating downtime associated with manual chemical cleaning procedures.
Solution Approach 2:
The plating bath acts as an intermediary medium that enables residual removal without direct human intervention or external chemical agents. By utilizing the existing plating bath and applying controlled electrical signals, the system mediates the cleaning process automatically, maintaining tool availability while achieving effective residual removal.
3Reliability
If thick residual builds up on contact pins, then electrical contact degradation occurs, but frequent cleaning increases process complexity
Solution Approach 1:
The system implements periodic cleaning cycles at predetermined intervals based on usage counters or time thresholds. Instead of continuous monitoring or complex real-time detection systems, the controller automatically initiates de-plating sequences at scheduled intervals to prevent residual buildup before it degrades electrical contact quality, simplifying the overall control architecture.
Solution Approach 2:
The controller monitors cleaning cycle counts and usage parameters to determine when de-plating is required. This feedback mechanism triggers automated cleaning sequences based on accumulated usage, preventing residual buildup that would degrade contact performance while avoiding unnecessary cleaning operations that would increase process complexity.
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 plating-de-plating process effectively removes thick residual from contact pins without manual chemical etching, reducing clean time and improving tool availability, while ensuring environmental and health safety by using the same plating bath for both deposition and cleaning, without strong acids or oxidizers.
Implementation Method 1
An electrochemical deposition (ECD) process, also known as electroplating or simply plating, is often used for metallization during fabrication of integrated circuits
Implementation Method 2
The controller is configured to apply a voltage signal across the contact ring and the electrode to remove residual from the contacts
Data Source
AI summary
An electrochemical deposition system configured for electrochemical plating of a substrate includes a chamber, an electrode, a plating cup and a controller. The chamber holds a plating bath. The electrode is disposed in the plating bath. The plating cup includes a contact ring. The contact ring includes contacts. The contacts are immersed in the plating bath. The controller is configured to apply a voltage signal across the contact ring and the electrode to remove residual from the contacts. The voltage signal includes a plating-de-plating waveform. The plating-de-plating waveform includes multiple cycles. Each of the cycles includes a pair of pulses with different polarity.