Pulsed Plasma OES Synchronization for Phase-Resolved Characterization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical emission spectroscopy (OES) methods for plasma process characterization in semiconductor manufacturing have limited time resolution, which makes it difficult to accurately monitor plasma stability and power modulation pulse stability during pulsed plasma processes.
Innovation Solution
The method involves synchronizing OES data acquisition with pulsed RF generators in plasma processing systems, allowing for selective OES signal observation and characterization during specific phases of the power modulation cycle, thereby enhancing time resolution to the millisecond or sub-millisecond scale.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional OES methods are used for plasma process characterization, then the measurement can be performed continuously, but the time resolution is limited and cannot accurately monitor plasma stability during pulsed plasma processes
Solution Approach 1:
The patent applies periodic action by synchronizing OES measurements with the pulsed plasma power modulation cycle. The system performs OES measurements at specific phases (overshoot, stable-ON, decay) of each power pulse, enabling time-resolved characterization of plasma parameters. This periodic synchronization allows the system to capture plasma stability information at millisecond or sub-millisecond time scales, directly resolving the contradiction between continuous measurement capability and time resolution limitation.
2Loss of information
If OES measurements are performed continuously without synchronization, then all plasma phases are captured, but the capability to characterize specific plasma parameters during specific phases is reduced
Solution Approach 1:
The patent applies segmentation by dividing the plasma power modulation cycle into distinct phases (overshoot period, stable-ON period, decay period) and performing OES measurements selectively during specific phases. The system segments the measurement process to capture plasma parameters at different stages of the power cycle, preventing loss of phase-specific information while maintaining measurement efficiency through targeted data collection rather than continuous monitoring of all phases.
Solution Approach 2:
The patent applies preliminary action by pre-synchronizing the OES measurement timing with the pulsed power signal phases. The system is configured to perform measurements at predetermined time points within each power pulse cycle based on the known pulse waveform characteristics. This preliminary timing arrangement ensures that plasma phase-specific information is captured without requiring real-time adaptive measurement decisions, thereby maintaining high measurement efficiency.
3Manufacturing precision
If the minimum dimension of features in patterned layers is reduced, then more complex structures can be fabricated, but the need for improved process characterization increases to assure process compliance
Solution Approach 1:
The patent applies feedback by using the synchronized OES measurements to monitor plasma parameters in real-time during pulsed plasma processes. The system characterizes plasma stability and parameters (such as electron density, radical concentration) at different phases of the power cycle, providing feedback information that can be used to control and optimize the plasma process. This feedback mechanism enables precise control of manufacturing parameters for advanced structures while the automated synchronization reduces the operational complexity of the characterization system.
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 improves the capability to monitor plasma stability and characterizes plasma parameters with higher precision, leading to better process control and reduced costs in semiconductor manufacturing.
Implementation Method 1
generating a pulsed plasma in a plasma processing chamber of the plasma processing system, the pulsed plasma being powered with a pulsed power signal
Implementation Method 2
performing cyclic optical emission spectroscopy (OES) measurements for the pulsed plasma
Data Source
AI summary
A method of characterizing a plasma in a plasma processing system that includes: generating a pulsed plasma in a plasma processing chamber of the plasma processing system, the pulsed plasma being powered with a pulsed power signal, each pulse of the pulsed plasma including three periods: a overshoot period, a stable-ON period, and a decay period; performing cyclic optical emission spectroscopy (OES) measurements for the pulsed plasma, the cyclic OES measurements including: obtaining first OES data during one of the three periods from more than one pulses of the pulsed plasma; and obtaining a characteristic of the pulsed plasma for the one of the three periods based only on the first OES data.