Etching Rate Monitoring for Inclined Hole Angle Prediction
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Solution Overview
Problem
The challenge in semiconductor integrated circuits is to monitor and predict the inclination angle of etched holes in capacitors during the etching process, as excessive inclination can lead to capacitor failure or collapse, and existing methods like SEM measurements are costly and lack real-time performance.
Innovation Solution
A method and device that monitor the etching rate change curve to predict when the inclination angle of etched holes exceeds a preset angle, using a processor to determine the etching rate change range and send alarm information when necessary, allowing for real-time prediction and maintenance of the etching device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SEM measurements are used to monitor inclination angle, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces an intermediary parameter (etching rate) that can be easily measured and correlates with the inclination angle. By monitoring the etching rate change curve instead of directly measuring the inclination angle, the system achieves indirect monitoring with much simpler equipment while maintaining effective process control.
Solution Approach 2:
The patent replaces complex mechanical/optical measurement systems (SEM) with a simpler sensing approach based on electrical parameter monitoring (etching rate measurement). This substitution enables real-time monitoring without the complexity and cost of SEM equipment.
2Productivity
If real-time monitoring is implemented, then productivity is improved, but device complexity increases
Solution Approach 1:
The patent uses etching rate as an intermediary parameter that provides real-time information about the etching process state. This intermediary measurement enables real-time prediction of inclination angle without requiring complex real-time imaging or measurement systems.
Solution Approach 2:
The etching process itself generates the monitoring signal through changes in etching rate. The system leverages the natural variations in etching rate that occur during the process, converting these inherent process variations into useful monitoring information without requiring additional active sensing mechanisms.
3Device complexity
If traditional monitoring methods are used, then device complexity is reduced, but measurement precision and real-time performance deteriorate
Solution Approach 1:
The patent introduces etching rate as an intermediary parameter that bridges the gap between simple measurement capability and precise inclination angle information. The etching rate serves as a proxy indicator that correlates with inclination angle, enabling accurate inference through simple measurements.
Data Source
AI summary
A method for predicting an inclination angle of an etched hole can include operations as follows. A preset change range of an etching rate of an etching device for an object to be etched on a surface of a monitored sample in different operation stages is determined. An etching rate change curve of the etching device for the object to be etched on the surface of a monitored sample in a current operation stage is acquired. When the etching rate change curve exceeds the preset change range, it is determined that an inclination angle of an etched hole of an etched product currently etched by the etching device exceeds a preset angle.