Imaging nano-defects of metal waveguides using the microwave cavity interference enhancement method

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Accurate imaging of nano-defects on metal waveguides is crucial for microelectronics.
• Existing methods may lack the resolution, cost-effectiveness, or real-time capabilities required for modern chip inspection.

Purpose of the Study:

• To develop and demonstrate a novel microwave (MW) cavity interference enhancement method for imaging nano-defects.
• To achieve high-resolution, real-time surface topography mapping of metal waveguides.

Main Methods:

• Utilized a microwave coaxial resonant cavity with a nano-probe for signal interference and enhancement.
• Split MW signals into reference and direct channels, with coupling strength dependent on probe-waveguide distance.
• Mapped surface topography by analyzing enhanced interference signals.

Main Results:

• Successfully detected weak signals (∼1 pW) using an MW cavity with a quality factor of ∼209.
• Achieved a resolution of ∼15 nm for mapping nano-defects on a metal waveguide surface.
• Demonstrated the system's capability for real-time online monitoring.

Conclusions:

• The developed MW cavity interference enhancement method provides a high-resolution, low-cost, and easy-to-manufacture approach for nano-defect imaging.
• This technique has broad potential applications in chip manufacturing, inspection, and nano-structure detection.