Multi-Channel Pulsed RF Power Supply for Uniform Plasma Density
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Solution Overview
Problem
In semiconductor manufacturing, achieving uniform plasma density across a larger substrate in a single chamber is challenging due to increased RF frequencies causing non-uniformity, and simultaneous processing of multiple wafers with synchronized pulsed RF power supply is difficult, leading to inconsistent processes.
Innovation Solution
A multi-channel pulsed RF power supply apparatus with multiple electrodes, RF signal generation units, matching boxes, and a multi-output pulse controller ensures consistent pulse plasma generation by applying synchronized RF signals with configurable pulse width and delay to multiple electrodes in a single chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If RF frequencies are increased to generate plasma with higher efficiency and density, then plasma generation efficiency is improved, but plasma density uniformity deteriorates due to wavelength effect and skin effect causing non-uniform distribution
Solution Approach 1:
The upper electrode is divided into multiple independent electrode parts (first electrode part, second electrode part, etc.) that can be independently controlled. Each electrode part receives RF power through separate RF power generators, allowing independent adjustment of plasma density in different regions to achieve uniform overall distribution while maintaining high frequency operation
2Productivity
If multiple RF power generators are used to process multiple wafers simultaneously in a single chamber, then productivity is improved, but process consistency deteriorates due to out-of-sync power supply
Solution Approach 1:
A pulse controller is introduced that centrally coordinates multiple RF power generators, merging their control functions into a single synchronization system. The pulse controller generates synchronized pulse signals that are distributed to all RF power generators, ensuring they operate in unison and deliver consistent pulsed power to multiple electrodes simultaneously, thereby maintaining process consistency while enabling multi-wafer processing
3Adaptability or versatility
If the chamber size is increased to process larger substrates, then adaptability is improved, but plasma density uniformity deteriorates due to increased distance and wavelength effects
Solution Approach 1:
The electrode structure is segmented into multiple independently controllable parts distributed across the large chamber. This segmentation allows localized plasma density control in different regions of the expanded chamber, compensating for the wavelength effects and distance-related non-uniformities that arise from the larger processing area
Solution Approach 2:
Each electrode part and its corresponding RF power generator form a locally optimized plasma generation zone. The system applies local quality control by adjusting parameters (frequency, power, pulse width) independently for each electrode part, ensuring uniform plasma density across the entire large chamber while accommodating various substrate sizes
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
This solution enables uniform plasma density and consistent pulsed processes across multiple substrates in a single chamber, enhancing processing efficiency and productivity while maintaining synchronized power supply.
Implementation Method 1
multiple RF signal generation units provided in the same number as the multiple electrodes to generate RF (Radio Frequency) signals having a predetermined frequency and phase
Implementation Method 2
electrons accelerated by a high-frequency electric field between the two electrodes, secondary electrons emitted from the electrodes, or heated electrons cause ionization collision with molecules in a processing gas to generate a plasma of the processing gas
Implementation Method 3
multiple matching boxes provided in the multiple RF signal application units, respectively, to sense reflected waves transmitted from the electrodes and automatically perform impedance matching functions so that the reflected waves become '0'
Implementation Method 4
a multi-output pulse controller provided to be connected to each of the multiple RF signal generation units so as to provide multiple output pulse signals with the same pulse frequency, and a pulse width and a pulse delay that are configurable, to the multiple RF signal generation units
Data Source
AI summary
The present disclosure relates to a multi-channel pulsed RF power supply apparatus capable of applying same pulse RF signals to multiple electrodes, respectively, so as to generate consistent pulse plasma while carrying out a pulsed process in a single chamber, wherein the multi-channel pulsed RF power supply apparatus includes multiple electrodes provided in a single chamber; multiple RF signal generation units provided in the same number as the multiple electrodes to generate RF (Radio Frequency) signals having a predetermined frequency and phase; multiple RF signal application units that connect the multiple RF signal generation units and the multiple electrodes in a one-to-one manner to apply the RF signals to the multiple electrodes, respectively; multiple matching boxes provided in the multiple RF signal application units, respectively, to sense reflected waves transmitted from the electrodes and automatically perform impedance matching functions so that the reflected waves become “0”; and a multi-output pulse controller provided to be connected to each of the multiple RF signal generation units so as to provide multiple output pulse signals with the same pulse frequency, and a pulse width and a pulse delay that are configurable, to the multiple RF signal generation units.