Electrostatic Chuck Voltage Breakdown Detection
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Solution Overview
Problem
It is difficult to detect arcing or high voltage breakdown conditions in electrostatic chucks used in workpiece processing systems, leading to catastrophic failures that result in downtime, damaged equipment, and increased costs due to the inability to take corrective action until damage occurs.
Innovation Solution
A system and method that samples the output of an electrostatic chuck's power supply at high frequency, converts it into a frequency spectrum, and compares it to reference models to detect impending failures, displaying results to operators and identifying the cause of potential failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional monitoring methods are used for electrostatic chucks, then the system structure remains simple, but failure detection is delayed until catastrophic failure occurs
Solution Approach 1:
The patent replaces traditional mechanical/arcing-based failure modes with an electrical monitoring system that measures current draw and power consumption. By substituting direct physical failure detection with electrical parameter monitoring, the system achieves early failure detection without adding complex mechanical sensors to the electrostatic chuck structure.
Solution Approach 2:
The system implements continuous feedback monitoring of electrical parameters (current, power) from the electrostatic chuck's power supply. This feedback loop enables real-time detection of deviations from normal operation, allowing the system to identify impending failures before they manifest as catastrophic breakdowns or arcing events.
2Force
If high-voltage electrostatic fields are applied to clamp workpieces, then workpiece holding force is sufficient, but arcing and voltage breakdown occur undetected
Solution Approach 1:
The patent introduces electrical parameter measurements (current draw, power consumption) as intermediary indicators that mediate between the high-voltage electrostatic field and detectable failure signs. Instead of directly detecting arcing or voltage breakdown in the high-voltage field, the system monitors these phenomena through their effects on power supply electrical parameters, making invisible failures detectable.
Solution Approach 2:
The system replaces direct optical or electrical field-based arcing detection with indirect electrical parameter monitoring. By measuring changes in current and power consumption in the power supply circuit, the system substitutes complex arcing detection mechanisms with simpler electrical measurements that correlate with impending failure conditions.
3Productivity
If corrective action is taken only after failure occurs, then the monitoring system remains simple, but productivity is lost due to downtime and equipment damage
Solution Approach 1:
The system performs preliminary detection of failure conditions by continuously monitoring electrical parameters and comparing them against baseline profiles. By identifying deviations that indicate impending failure before actual breakdown occurs, the system enables preliminary corrective actions that prevent catastrophic failures, workpiece damage, and unplanned downtime.
Solution Approach 2:
The monitoring system automatically detects failure conditions and generates alerts without requiring manual inspection or intervention. The system serves itself by continuously self-diagnosing its operational status through electrical parameter monitoring, enabling automated predictive maintenance that reduces productivity loss from unexpected failures.
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
Enables early detection of impending failures, reducing downtime and costs by allowing for preventive action before damage occurs, and minimizing the risk of chuck and workpiece damage.
Implementation Method 1
The top layer, also referred to as the dielectric layer, contacts the workpiece, and is made of an electrically insulating or semiconducting material, such as alumina with embedded metal electrodes, since it produces the electrostatic field without creating a short circuit.
Implementation Method 2
It is difficult to detect arcing or high voltage breakdown conditions occurring at or near the electrostatic chucks
Data Source
AI summary
A system, instructions and a method of determining when an impending failure is likely to occur absent corrective action are disclosed. The system samples the output of a power supply which powers an electrostatic chuck, and determines when that output is outside acceptable limits. The output is sampled at a sufficiently high frequency so as to detect transient anomalies, which are not detectable at lower sampling rates. In some embodiments, the output is converted to a frequency spectrum. The empirical model is compared to known good reference models and, in some embodiments, failure reference models of known failure modes to determine whether an impending failure will occur, and which type of failure.