In situ thickness determination of multilayered structures using single wavelength ellipsometry and reverse...

Area of Science:

• Materials Science
• Optical Engineering
• Thin Film Deposition

Background:

• Magnetron sputtering is a key technique for thin film deposition.
• Accurate control of layer thickness and optical properties is crucial for device performance.
• In situ monitoring can improve process control and reduce errors.

Purpose of the Study:

• To develop and integrate an in situ monitoring setup with a process control loop for magnetron sputtering.
• To enable real-time monitoring of layer thickness on moving substrates.
• To determine the complex index of refraction and implement in situ reverse thickness engineering.

Main Methods:

• Integration of a Sentech SE 401 single wavelength ellipsometer into a magnetron sputtering coater.
• Development of custom software for in situ process control and data acquisition.
• Utilizing ellipsometry data to monitor layer thickness and optical properties during deposition.

Main Results:

• The developed system allows direct, real-time monitoring of layer thickness on moving substrates.
• The complex index of refraction can be determined from the distribution of ellipsometric measurements.
• A strategy for in situ reverse thickness engineering was successfully developed to compensate for measurement errors.

Conclusions:

• The integrated in situ monitoring and control system significantly enhances production accuracy in magnetron sputtering.
• Real-time optical property determination and thickness control are achievable.
• The developed reverse engineering strategy improves the reliability of thin film deposition processes.