Dry Etching Process Control Device Using Plasma Emission Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling the etching amount in dry etching processes using plasma face challenges in achieving accurate control, particularly due to difficulties in precisely measuring and regulating the etching time and post-etching dimensions.
Innovation Solution
A process control device that calculates a total emission amount by integrating emission intensity over time during the dry etching process, using a specific wavelength of light, and outputs an instruction to stop the etching when a predetermined reference value is reached, allowing for precise control of the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If etching time is controlled to regulate etching amount, then etching process can be simplified, but etching amount control precision deteriorates
Solution Approach 1:
The patent implements real-time feedback control by monitoring plasma emission intensity during the etching process. The emission intensity serves as a real-time indicator of etching progress, allowing the system to adjust etching parameters dynamically to maintain precise control over etching amount while keeping the process relatively simple.
Solution Approach 2:
The patent replaces mechanical/time-based control methods with optical measurement methods. Instead of relying on timed etching processes, the system uses plasma emission spectroscopy to monitor etching progress in real-time, substituting mechanical timing mechanisms with optical sensing and control.
2Manufacturing precision
If after-etching dimension measurement with feedback is used to control etching amount, then etching amount control precision is improved, but measurement precision requirements and time lags increase
Solution Approach 1:
The patent substitutes post-etching dimensional measurements with real-time plasma emission monitoring. By measuring plasma emission intensity during the etching process, the system eliminates the need for high-precision dimensional measurement equipment and avoids time lags associated with post-process measurement and feedback.
Solution Approach 2:
The patent performs measurement during the etching process itself rather than after completion. By monitoring plasma emission in real-time, the system can detect etching progress before the process completes, allowing for mid-course corrections and eliminating the need for post-process measurement and iterative adjustments.
3Manufacturing precision
If real-time plasma emission monitoring is implemented to control etching amount, then etching amount control precision is improved, but device complexity increases
Solution Approach 1:
The patent uses plasma emission intensity as an intermediary parameter to control etching amount. Instead of directly measuring difficult-to-obtain parameters like real-time etching depth, the system monitors the readily measurable plasma emission intensity, which serves as a proxy indicator of etching progress, simplifying the overall measurement and control system.
4Manufacturing precision
If feedback-based dimension measurement is used, then etching amount control is achieved, but time lags in the control loop increase
Solution Approach 1:
The patent implements continuous monitoring of plasma emission intensity throughout the etching process. This continuous measurement approach eliminates the discrete, periodic nature of post-etching measurement methods, ensuring that control information is always current and eliminating time lags in the control loop.
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 enables accurate and consistent control of the etching amount, ensuring a desired trench depth is achieved regardless of the number of etching process steps, reducing variations and eliminating time lags associated with feedback-based methods.
Implementation Method 1
light generated while dry etching process using plasma is being executed
Data Source
AI summary
According to one embodiment, a process control device includes an emission amount calculation unit and a process control unit. The emission amount calculation unit selects light of a predetermined wavelength among light generated while a dry etching process is being executed on a substrate. The process control unit calculates an integral value which is obtained by integrating an emission intensity of the selected light with time of detecting the selected light. Further, the process control unit calculates a total amount of the integral value as a total emission amount at the substrate. Further, the process control unit outputs an instruction to stop the dry etching process when the total emission amount reaches a predetermined reference value.