Ion Implanter Extraction Electrode Glitch Reduction
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Solution Overview
Problem
Ion implanters experience glitches due to material buildup on extraction electrodes, leading to arcing and reduced manufacturing throughput and solar cell efficiency, particularly when using fluoride-containing gases like BF3.
Innovation Solution
Implementing plasma-assisted conditioning and cleaning methods, where the bias voltage to extraction electrodes is modified to inhibit ion beam formation and increase plasma density, and subsequently using a different source gas and adjusting electrode positions to remove material deposits, thereby reducing glitch rates and improving ion implanter reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion implantation is performed using fluoride-containing gases like BF3, then solar cell efficiency is improved, but glitch rate increases due to material buildup on extraction electrodes
Solution Approach 1:
The system performs preliminary plasma-assisted cleaning and conditioning of extraction electrodes before material buildup causes glitches. This preventive maintenance approach removes deposits before they interfere with normal operation, maintaining both reliability and productivity without interrupting the manufacturing process for extended periods.
Solution Approach 2:
The ion implanter system performs self-maintenance through automated plasma cleaning cycles that remove material buildup from extraction electrodes. The system monitors its own condition and initiates cleaning operations when needed, reducing the need for external intervention and maintaining continuous operation.
2Reliability
If plasma-assisted cleaning is performed to remove material deposits, then glitch rate is reduced, but manufacturing throughput is temporarily reduced due to process interruption
Solution Approach 1:
The system implements periodic plasma cleaning cycles at predetermined intervals or when glitch indicators are detected. This periodic maintenance approach balances cleaning effectiveness with productivity, performing brief cleaning operations that prevent major disruptions while maintaining continuous manufacturing flow.
Solution Approach 2:
The plasma cleaning process is designed to rapidly remove material deposits in brief, intense pulses rather than prolonged gentle cleaning. This rushing through the cleaning process minimizes interruption time while achieving the necessary removal of material buildup on electrodes.
3Manufacturing precision
If extraction electrodes are cleaned more frequently to maintain beam quality, then workpiece quality is improved, but device complexity and operation time increase
Solution Approach 1:
The system monitors beam quality parameters and electrode condition in real-time, using this feedback to determine when cleaning is actually needed. This condition-based maintenance approach adjusts cleaning frequency based on actual performance degradation rather than fixed schedules, optimizing both quality and operational efficiency.
Solution Approach 2:
The plasma generation system serves multiple functions: it generates ions for implantation during normal operation and simultaneously performs cleaning when activated. This multi-functionality reduces device complexity by using existing components for dual purposes rather than requiring separate dedicated cleaning equipment.
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 plasma-assisted methods effectively reduce glitch rates, maintain high throughput, and enhance the quality of implanted workpieces by smoothing electrode surfaces and removing material deposits, leading to increased ion implanter uptime and solar cell efficiency.
Implementation Method 1
The power supplied to the plasma generator in the ion source is increased, thereby creating a high density plasma
Implementation Method 2
a plasma generator in the ion source is operated at a first power level... operated at a second power level, greater than the first power level
Implementation Method 3
performing a plasma-assisted conditioning... in order to reduce a glitch rate... smoothing electrode surfaces and removing material deposits
Implementation Method 4
Energetic ions then condition the extraction electrodes... removing material from the extraction electrodes
Implementation Method 5
the bias voltage to the extraction electrodes is modified so as to inhibit the formation of an ion beam
Implementation Method 6
The energetic ions in the ion beam penetrate into the bulk of the workpiece material and are embedded into the crystalline lattice of the workpiece material to form a region of desired conductivity
Data Source
AI summary
Methods of reducing glitch rates within an ion implanter are described. In one embodiment, a plasma-assisted conditioning is performed, wherein the bias voltage to the extraction electrodes is modified so as to inhibit the formation of an ion beam. The power supplied to the plasma generator in the ion source is increased, thereby creating a high density plasma, which is not extracted by the extraction electrodes. This plasma extends from the ion source chamber through the extraction aperture. Energetic ions then condition the extraction electrodes. In another embodiment, a plasma-assisted cleaning is performed. In this mode, the extraction electrodes are moved further from the ion source chamber, and a different source gas is used to create the plasma. In some embodiments, a combination of these modes is used to reduce glitches in the ion implanter.