Multi-RF Plasma Power Control for Precise Substrate Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma processing technologies lack effective control over ion energy and flux, leading to inconsistent etching results and shape defects in substrates.
Innovation Solution
A plasma processing apparatus with a power supply system that employs multiple RF frequencies and voltage pulse signals to independently control ion energy and flux by alternating power levels and phases, using a combination of RF power supplies and a voltage pulse generator to manage ion behavior during etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple RF power supplies with different frequencies are used to control ion energy and flux, then plasma controllability is improved, but device complexity increases
Solution Approach 1:
The power supply system is segmented into multiple independent RF power supplies (first RF power supply for ion flux control, second RF power supply for ion energy control, third RF power supply for protective film formation) and a voltage pulse generator. Each power supply operates at different RF frequencies and controls specific plasma parameters independently, enabling precise control of ion flux, ion energy, and protective film formation separately, thus resolving the technical contradiction between improved etching precision and increased device complexity.
2Manufacturing precision
If voltage pulse signals are applied to control ion attraction, then etching quality is improved, but device complexity increases
Solution Approach 1:
A voltage pulse generator applies periodic voltage pulse signals to the lower electrode in synchronization with the RF power supply cycles. The voltage pulses are applied during specific periods (first and second periods) to attract ions perpendicular to the substrate surface, enhancing etching quality by ensuring consistent ion directionality and preventing shape defects. This periodic action integrates seamlessly with the multi-frequency RF system without requiring additional complex control mechanisms.
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
Enhances controllability of plasma on substrates, improving etching precision by promoting protective film formation, ensuring perpendicular ion attraction, and preventing shape defects, thereby enhancing etching quality.
Implementation Method 1
a first RF power supply configured to supply a first RF signal having a first RF frequency to the upper electrode or the lower electrode
Implementation Method 2
a voltage pulse generator configured to apply a voltage pulse signal to the lower electrode
Data Source
AI summary
A technique for improving controllability of plasma generated on a substrate is provided. A plasma processing apparatus includes a chamber, a substrate support disposed inside the chamber and including a lower electrode, an upper electrode disposed above the substrate support, a first RF power supply for supplying a first RF signal having a first RF frequency to the upper electrode or the lower electrode, a second RF power supply for suppling a second RF signal having a second RF frequency to the lower electrode, and a third RF power supply for supplying a third RF signal having a third RF frequency to the lower electrode. The three RF power supplies supply RF signals having respective power levels in three periods in each cycle.