What is it about?

This research presents the development of an ultrahigh-temperature vacuum probe station (UHT-VPS) capable of continuous electrical and thermal characterization of materials and electronic devices at unprecedented temperatures up to 1150 K (877°C) for over 66 hours without requiring probe readjustment. The innovative system employs a contactless silicon carbide (SiC) heater that transfers heat through thermal radiation to a physically isolated sample holder, eliminating electrical leakage and avoiding degradation issues associated with traditional ceramic insulators at extreme temperatures.

Featured Image

Why is it important?

This work extends far beyond laboratory curiosities. Modern wide-bandgap semiconductors like silicon carbide, gallium nitride, and diamond-based devices are increasingly required to operate reliably in harsh environments exceeding 1000 K, including applications in space exploration, nuclear plants, automotive electronics, deep-well drilling, and military systems . Current industry standards for High Temperature Operation Lifetime (HTOL) testing are limited to only 125-300°C, creating a critical gap between device requirements and characterization capabilities. This UHT-VPS bridges that gap, enabling wafer-level electrical testing at unprecedented temperatures, which is essential for selecting the most reliable devices before expensive packaging processes. The system’s capabilities were rigorously validated using an advanced 3ω/2ω electro-thermal method, incorporating advanced quadratic temperature coefficient of resistance (TCR) modeling to account for nonlinear material behavior at extreme temperatures. Both thermal conductivity and thermal diffusivity (usually, those 2 properties cannot be measured in a single experiment) of sapphire substrates was measured with remarkable accuracy (0.3% uncertainty), achieving results that agree with literature data across the entire temperature range - extending electrical measurements far beyond the previous limit of 780 K for this method. To go further, when designing sensors or electronic devices intended for space missions near the Sun, it is critical to guarantee long-term reliability under harsh thermal conditions. Accelerated lifetime testing, in which devices are operated for extended periods at temperatures above their nominal range, provides valuable insights into their durability. The ultrahigh-temperature prober enables such evaluations, making it an essential tool for assessing the reliability of high-value components.

Perspectives

The development of this system is an example of how engineering challenges can unlock new frontiers in physics research. Our journey began with an ambitious quest to detect elusive surface phonon polaritons (SPhPs) - tiny electromagnetic thermal waves that propagate across material surfaces, supported by a JST-CREST project (S. Volz, Pr. M. Nomura). My colleagues (co-authors) hypothesized that operating at high temperatures (around 800 K) could simplify this complex detection problem by suppressing the dominant contribution of bulk phonons, while allowing these delicate SPhP waves to propagate over long distances across the sample surface. However, when we surveyed approximately 16 companies offering commercially available vacuum probe stations, none could confidently guarantee continuous electrical measurements at 800 K. Rather than compromise our scientific vision, we decided to push the boundaries even further - developing a prototype capable of routinely operating at 1200 K, well beyond our initial requirements. This bold engineering decision proved successful, creating a tool that transcends our original research goals. The UHT-VPS now serves as a bridge between fundamental physics discovery and practical device characterization, offering unprecedented capabilities for both industrial quality control and academic research. By solving our specific challenge of detecting surface phonon polaritons, we inadvertently created an instrument that addresses a critical gap in high-temperature materials characterization - demonstrating how targeted solutions to fundamental physics problems can yield broadly transformative technologies.

Dr. Laurent Jalabert
LIMMS/CNRS-IIS The University of Tokyo

Read the Original

This page is a summary of: Ultrahigh-temperature vacuum prober for electrical and thermal measurements, Review of Scientific Instruments, August 2025, American Institute of Physics,
DOI: 10.1063/5.0272551.
You can read the full text:

Read

Resources

Contributors

The following have contributed to this page