Electrostatic Chuck Relay Control for Stable Plasma Wafer Adsorption
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Solution Overview
Problem
Existing plasma processing systems face challenges in accurately controlling the adsorption force of substrates during plasma processing, leading to excessive electrostatic forces that can damage the substrates due to fluctuations in self-bias voltage and increased friction, making it difficult to manage substrate handling and processing efficiency.
Innovation Solution
A plasma processing apparatus with a relay circuit in the power supply line to the electrostatic chuck, allowing controlled voltage supply to the electrostatic electrode, transitioning to a floating state during plasma processing, and monitoring current flow to detect charge leakage and determine the adsorption state, thereby preventing excessive electrostatic forces and substrate damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If voltage is continuously supplied to the electrostatic electrode to maintain substrate adsorption, then substrate adsorption stability is improved, but substrate damage due to excessive electrostatic force increases
Solution Approach 1:
The patent applies periodic action by intermittently supplying voltage to the electrostatic electrode rather than continuously. The controller periodically turns the voltage supply ON and OFF, maintaining substrate adsorption stability while preventing excessive electrostatic force accumulation that could damage the substrate.
Solution Approach 2:
The patent implements dynamics by making the voltage supply state changeable between ON and OFF based on processing requirements. The electrostatic electrode transitions from a static continuous voltage state to a dynamic intermittent voltage state, allowing adaptation to different processing phases and preventing substrate damage.
2Stability of the object's composition
If voltage is supplied to the electrostatic electrode during plasma processing, then substrate adsorption is maintained, but friction increases causing handling difficulties
Solution Approach 1:
The patent uses periodic action to supply voltage intermittently during plasma processing. By turning the voltage supply OFF during specific processing phases, the patent reduces friction between the substrate and electrostatic electrode, making substrate handling easier while maintaining adsorption when needed.
3Object-affected harmful factors
If voltage supply is interrupted to reduce electrostatic force, then substrate damage is prevented, but adsorption stability deteriorates
Solution Approach 1:
The patent resolves this contradiction through periodic voltage supply. The controller periodically restores voltage supply to maintain adsorption stability after interrupting it to prevent damage. This rhythmic ON-OFF pattern ensures both damage prevention and adsorption stability are achieved at different phases.
Solution Approach 2:
The patent maintains continuity of useful action by periodically restoring voltage supply to the electrostatic electrode. Although voltage is intermittently supplied, the periodic restoration ensures that adsorption functionality continues throughout the processing cycle, preventing complete loss of adsorption stability.
4Adaptability or versatility
If self-bias voltage is allowed to fluctuate during plasma processing, then processing flexibility is improved, but substrate damage due to excessive electrostatic force increases
Solution Approach 1:
The patent applies periodic action to control voltage supply in response to self-bias voltage fluctuations. When self-bias voltage fluctuates within acceptable ranges, the controller maintains voltage supply for processing flexibility. When fluctuations exceed thresholds, the controller interrupts voltage supply to prevent substrate damage, achieving both flexibility and protection.
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 solution effectively maintains stable adsorption forces by detecting charge leakage, preventing substrate bouncing and damage, and ensuring consistent substrate handling throughout the processing cycle.
Implementation Method 1
configured to adsorb a substrate by a voltage supplied to the electrostatic electrode
Implementation Method 2
generate a plasma inside the plasma processing chamber
Data Source
AI summary
A plasma processing apparatus includes an electrostatic chuck that adsorbs a substrate, a relay circuit that turns ON and OFF the supply of voltage to the electrostatic electrode, a plasma generator, and a controller. The controller (a) controls the DC power supply to supply the voltage to the electrostatic electrode, thereby adsorbing the substrate to the electrostatic chuck, (b) controls the relay circuit to turn OFF the supply of the voltage to the electrostatic electrode, thereby bringing the electrostatic electrode into a floating state, (c) controls the plasma generator to start a plasma processing of the substrate, (d) controls the relay circuit to turn ON the supply of the voltage to the electrostatic electrode, thereby acquiring current flowing through the power supply line, and (e) determines an adsorbed state of the substrate based on the current.