Plasma Electrode Bias Switching for Ion Energy Distribution Control
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Solution Overview
Problem
Existing plasma processing technologies face challenges in efficiently controlling ion energy distribution during plasma processing on substrates, leading to inconsistent treatment outcomes.
Innovation Solution
A plasma processing method involving alternating application of direct-current voltages with different levels but the same polarity to a substrate support electrode, combined with controlled switching to ground potential, to manage ion energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single direct-current voltage level is applied to the substrate holding electrode, then the plasma processing apparatus structure is simple, but the ion energy distribution is insufficiently controlled leading to inconsistent treatment outcomes
Solution Approach 1:
The patent applies periodic switching between multiple direct-current voltage levels (first DC voltage and second DC voltage) to the substrate holding electrode. This periodic voltage application creates controlled variations in ion energy distribution, allowing ions to be supplied at different energy levels at different time periods, thereby achieving consistent and controllable plasma processing outcomes while managing system complexity through temporal modulation rather than spatial complexity
Solution Approach 2:
The patent changes the voltage parameter applied to the substrate holding electrode by switching between at least two different direct-current voltage levels. This parameter change enables control over ion energy distribution, as the different voltage levels correspond to different ion energies, allowing optimization of plasma processing consistency through electrical parameter modulation
2Manufacturing precision
If multiple voltage levels are applied to control ion energy, then processing consistency improves, but the control system complexity increases
Solution Approach 1:
The system employs periodic switching between multiple voltage levels using a controller that alternates application of first and second DC voltages to the substrate holding electrode. This periodic control mechanism achieves precise ion energy distribution management through time-based modulation, improving processing consistency while keeping the control system manageable through regular, predictable switching patterns rather than complex continuous control
Solution Approach 2:
The patent introduces dynamic voltage control by switching between different DC voltage levels based on processing requirements. The substrate holding electrode transitions between different electrical states (different voltage levels) to dynamically adjust ion energy distribution, enabling adaptive control of plasma processing parameters while maintaining a relatively simple hardware architecture through temporal dynamics
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 approach allows for a controlled range of ion energies to be applied to the substrate, enhancing processing consistency and efficiency by maintaining a balanced ion energy distribution throughout the process.
Implementation Method 1
applying a first direct-current voltage to a lower electrode of a substrate support provided in a chamber of a plasma processing apparatus, in a first period during generation of plasma in the chamber... applying a second direct-current voltage to the lower electrode in a second period different from the first period during generation of the plasma in the chamber... The second direct-current voltage has a level different from a level of the first direct-current voltage... The energy of ions which are supplied to the substrate when the direct-current negative pulse voltage, that is, a negative pulsed direct-current voltage is applied to the substrate holding electrode becomes the maximum.
Data Source
AI summary
A plasma processing method according to an exemplary embodiment includes applying a first direct-current voltage to a lower electrode of a substrate support provided in a chamber of a plasma processing apparatus, in a first period during generation of plasma in the chamber. The plasma processing method further includes applying a second direct-current voltage to the lower electrode in a second period different from the first period during generation of plasma in the chamber. The second direct-current voltage has a level different from a level of the first direct-current voltage. The second direct-current voltage has a same polarity as a polarity of the first direct-current voltage.