High-resolution subsurface microscopy of CMOS integrated circuits using radially polarized light

Area of Science:

• Optics and Photonics
• Materials Science
• Electrical Engineering

Background:

• High numerical aperture (NA) microscopy faces resolution limits.
• Light polarization significantly impacts focusing characteristics.
• Subsurface imaging requires advanced optical techniques.

Purpose of the Study:

• To evaluate the performance of radially polarized light in high-NA microscopy.
• To investigate resolution improvements in two-photon optical-beam-induced current (OBIC) microscopy.
• To compare imaging resolution using radial versus linear polarization.

Main Methods:

• Utilized a solid-immersion-lens microscopy setup.
• Employed two-photon optical-beam-induced current (OBIC) imaging.
• Compared subsurface imaging of complementary metal-oxide semiconductor (CMOS) integrated circuits under radial and linear polarization.

Main Results:

• Radial polarization achieved a resolution of 126 nm.
• Linear polarization yielded resolutions of 122 nm and 165 nm, dependent on E-field orientation.
• Superior feature definition was observed with radial polarization.

Conclusions:

• Radially polarized light offers improved resolution in high-NA microscopy.
• This technique enhances subsurface imaging of integrated circuits.
• Results align with theoretical predictions for polarized light focusing.