Polarimetric photoluminescence microscope for strain imaging on semiconductor devices

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Anisotropic strain in cubic semiconductor crystals (e.g., GaAs, InP) leads to partial linear polarization of emitted photoluminescence (PL).
• Characterizing strain is crucial for understanding and optimizing semiconductor device performance.

Purpose of the Study:

• To present a novel polarimetric photoluminescence microscope for characterizing anisotropic strain in semiconductor devices.
• To enable quantitative measurement of strain through PL polarization analysis.

Main Methods:

• Development of a polarimetric photoluminescence microscope.
• Measurement of the degree of linear polarization (DOLP) and polarization angle of PL.
• Mapping anisotropic strain in GaAs induced by a surface stressor film (SiNx).

Main Results:

• The developed microscope effectively maps anisotropic strain distributions.
• Demonstrated high sensitivity with a DOLP resolution as low as 4.5×10⁻⁴ on GaAs.
• Successfully visualized strain generated by a patterned SiNx stressor film.

Conclusions:

• The polarimetric PL microscope is a powerful tool for semiconductor device characterization.
• Quantitative analysis of PL polarization provides detailed insights into material strain.
• This technique offers high resolution for strain mapping in semiconductor materials.