Plasma Processing Voltage Control for Opening Tilt Stability
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Solution Overview
Problem
Plasma processing devices face issues with process characteristic deterioration due to wear of chamber members and individual differences in machine characteristics, leading to tilting of substrate openings and other processing inaccuracies.
Innovation Solution
A control program that adjusts peak-to-peak voltage parameters, including source power, bias power, direct-current voltage applied to the outer peripheral member, and impedance of a filter circuit, to maintain consistent process characteristics despite wear and machine differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the outer peripheral member is used in plasma processing, then plasma processing can be performed, but the outer peripheral member wears and thickness is reduced causing opening tilting
Solution Approach 1:
The patent applies direct-current voltage to the outer peripheral member to change the electrical parameter of the plasma environment. This voltage application modifies the ion behavior and sheath characteristics, preventing ions from colliding with the substrate edge at tilted angles, thereby maintaining opening formation precision despite member wear
Solution Approach 2:
The patent applies direct-current voltage in advance to the outer peripheral member before plasma processing occurs. This preliminary electrical conditioning prevents the wear-induced tilting effect from occurring during the actual plasma processing, maintaining consistent opening formation quality
2Manufacturing precision
If direct-current voltage is applied to prevent opening tilting, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The outer peripheral member serves multiple functions: it defines the processing region boundary and simultaneously acts as an electrode for direct-current voltage application. This multi-functionality allows the same component to provide both structural definition and electrical control, avoiding additional dedicated electrodes or complex control systems
3Stability of the object's composition
If multiple parameters are adjusted to maintain process characteristics, then process consistency is improved, but control complexity increases
Solution Approach 1:
The patent employs feedback control by monitoring peak-to-peak voltage between source power and bias power, and using this information to automatically adjust the direct-current voltage applied to the outer peripheral member. This closed-loop control maintains process characteristic consistency while automating the adjustment process, reducing manual intervention complexity
Data Source
AI summary
A control program for a plasma processing device that executes plasma processing by supplying source power to a plasma generation source and supplying bias power to a stage on which a substrate to be processed is placed, and the control program causes a computer to observe a peak-to-peak voltage between the source power and the bias power, and adjust the source power supplied to the plasma generation source, the bias power supplied to the stage, a direct-current voltage applied to an outer peripheral member disposed around the stage, and an impedance of a filter circuit connected between a source of the direct-current voltage and the outer peripheral member, the source power, the bias power, the direct-current voltage and the impedance being adjustment parameters for controlling a fluctuation width of the observed peak-to-peak voltage.