In Situ Process Control during Wet-Chemical Etching of Heteroepitaxial III-V Layers Using Reflection Anisotropy...

Area of Science:

• Materials Science
• Surface Science
• Renewable Energy

Background:

• Semiconductor surface preparation for optoelectronics demands precise control.
• Vacuum-based techniques are standard, but wet-chemical etching offers a scalable, resource-efficient alternative.
• In situ monitoring is crucial for controlling wet-chemical etching processes.

Purpose of the Study:

• To demonstrate reflection anisotropy spectroscopy (RAS) as a powerful in situ monitoring tool for wet-chemical etching.
• To utilize RAS for precise control of etching depth, rate, and time.
• To validate RAS for developing and controlling etching routines for photoelectrodes.

Main Methods:

• Employing reflection anisotropy spectroscopy (RAS), a nondestructive optical technique.
• Observing Fabry-Pérot-type oscillations in reflectance and RAS transients during etching.
• Applying RAS for in situ monitoring of wet-chemical etching processes.

Main Results:

• RAS enables precise determination of etching depth (±8 nm) and rate.
• Fabry-Pérot oscillations confirm surface uniformity within the etching parameter space.
• RAS control was successfully validated for two different photoelectrode types.

Conclusions:

• RAS is a highly effective in situ technique for controlling wet-chemical etching of semiconductor surfaces.
• This method enhances the development of efficient etching routines for renewable energy applications.
• RAS provides a scalable and resource-efficient approach to optoelectronic device fabrication.