Scanning thermal imaging by near-field fluorescence spectroscopy

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Accurate temperature mapping is crucial for understanding and optimizing electronic device performance.
• Conventional thermal microscopy techniques face limitations in spatial resolution and sensitivity.
• Development of advanced probes is needed for high-resolution thermal imaging.

Purpose of the Study:

• To develop a novel scanning thermal microscope (STM) utilizing a fluorescent particle as a temperature probe.
• To demonstrate the capability of this new STM for high-resolution thermal imaging of electronic devices.
• To validate the accuracy of the developed method through comparison with numerical simulations.

Main Methods:

• Fabrication of a temperature probe by attaching a rare-earth ion-doped fluoride glass particle to a sharp tungsten tip.
• Scanning the fluorescent particle probe across the surface of an electronic device.
• Measuring the fluorescence spectrum of the particle at each point to determine local temperature by analyzing intensity variations of two emission lines.

Main Results:

• Successful development of a scanning thermal microscope employing a fluorescent particle probe.
• Acquisition of thermal images on a 1-micrometer wide nickel stripe heated by electrical current.
• Demonstrated good agreement between experimental temperature measurements and simulation results of the temperature field.

Conclusions:

• The developed fluorescent particle-based scanning thermal microscope is a viable tool for high-resolution thermal analysis of microelectronic devices.
• The method offers accurate temperature determination by analyzing fluorescence spectral changes.
• This technique shows promise for non-contact, high-resolution thermal characterization in microelectronics.