Modular Pulse Generator Coupling for High-Voltage Plasma Pulses
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Solution Overview
Problem
Plasma treatment applications, such as etching or layer deposition, require high voltage and high frequency rectangular, asymmetrical, pulsed voltage supplies, which exceed the voltage handling capabilities of individual semiconductor switches, especially during high frequency operation.
Innovation Solution
A high power generator configured with multiple low power generators, each with an energy storage component, electrically connected through a coupling to achieve higher output values, and a control unit that selectively activates the generators to generate step-function pulses without continuous slopes, utilizing LP-generator-value limiting circuits to manage overvoltage and current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If individual semiconductor switches are used to generate high voltage pulses, then the voltage handling capability is limited, but using multiple switches in series increases device complexity
Solution Approach 1:
The high power generator is segmented into multiple low power generators, each with its own energy storage component. These modular units can be independently controlled and combined to achieve the required high voltage output, avoiding the need for complex series-connected semiconductor switches while maintaining voltage handling capability.
Solution Approach 2:
Instead of increasing voltage handling capability by stacking semiconductor switches in series (vertical dimension), the invention transitions to combining multiple independent low power generators in parallel (horizontal dimension), each operating within its safe voltage range but collectively delivering high voltage pulses through controlled switching and energy storage.
2Productivity
If high frequency operation is required for plasma treatment, then the voltage demands exceed semiconductor switch capabilities, but increasing switch voltage rating increases device complexity and reduces efficiency
Solution Approach 1:
Energy storage components are charged to predefined values before the high frequency pulse operation is required. This preliminary charging allows the system to rapidly deliver high voltage pulses at high frequencies without requiring semiconductor switches to continuously handle peak voltages, thereby enabling high frequency operation while maintaining manageable device complexity.
3Power
If multiple low power generators are combined to achieve high power output, then the coupling complexity increases, but this enables scalable power delivery
Solution Approach 1:
Multiple low power generators are merged through a coupling mechanism that combines their outputs. The coupling integrates the individual generator outputs in a controlled manner, enabling scalable power delivery where the total power output can be adjusted by activating different combinations of low power generators, thus achieving high power capability while managing coupling complexity through modular design.
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 efficient delivery of high power pulses with sharp voltage transitions and reduced power losses, effectively addressing the limitations of existing technologies in plasma processes by providing a reliable and efficient high voltage supply.
Implementation Method 1
a series circuit of a diode and a capacitor configured to clamp an overvoltage present at ends thereof to a voltage that the capacitor is charged up
Data Source
AI summary
A high power (HP) generator includes a plurality of low power (LP) generators, a coupling in which the LP generators are electrically connected, and a control unit. During operation, a coupling-value at an output of the coupling is higher than an LP-generator-value at an output of one of the LP generators. The control unit is configured to select a contribution of each LP generator in order to generate a rise and/or a decay of a pulse at the output of the coupling. At least one LP generator includes an LP-generator-value limiting circuit. The LP-generator-value limiting circuit includes at least one of (i) a series circuit of a diode and a capacitor configured to clamp an overvoltage present at ends thereof, and a discharge circuit to discharge the capacitor, or (ii) a resistor and a switching element, or (iii) a variable electrically controllable impedance with a power dissipating part.