Semiconductor Oxide Film Measurement 'Absolute Thickness' Established by Korean Researchers

Korea Standard Research Institute Successfully Establishes International Standards

Researchers from the KRISS Surface Analysis Team are measuring the thickness of an ultrathin film. Photo by Korea Research Institute of Standards and Science

[Asia Economy Reporter Kim Bong-su] The Korea Research Institute of Standards and Science (KRISS) announced on the 30th that it has succeeded in establishing an international standard for measuring semiconductor oxide film thickness below 1 nanometer (nm, one billionth of a meter) using advanced measurement equipment developed with domestic small and medium-sized enterprise technology.

The Surface Analysis Team of the Materials Convergence Measurement Laboratory at KRISS confirmed for the first time in the world that the absolute thickness of semiconductor oxide films below 1 nm can be precisely measured using the domestically produced Medium Energy Ion Scattering Spectrometer (MEIS). This technology has begun to be utilized as an international standard, having been adopted at an international conference as the method for determining the reference thickness of hafnium oxide films. Absolute thickness refers to the actual thickness unaffected by other factors, in contrast to relative thickness.

The core achievement of this result is securing key measurement technology for semiconductor device manufacturing processes using domestically produced advanced measurement equipment. By providing the highest level of measurement reliability to domestic semiconductor device companies, it is expected to further expand the ultra-gap technology that foreign companies cannot catch up with.

In semiconductor integrated circuit manufacturing processes, controlling the substrate oxide film to be thin and uniform in thickness is very important. The oxide film protects the surface and simultaneously controls electron movement, serving as a core function in the semiconductor’s electronic properties and circuit design.

Until now, semiconductor processes have measured oxide film thickness using Transmission Electron Microscopy (TEM), Spectroscopic Ellipsometry (SE), and X-ray Reflectometry (XRR). The problem was that the thickness measured by these methods showed significant differences from the actual thickness.

The KRISS Surface Analysis Team revealed that X-ray Photoelectron Spectroscopy (XPS), which had been used as a standard for measuring semiconductor oxide film thickness, is difficult to use as a measurement standard, and proposed MEIS as an alternative. Through systematic comparative studies on thickness measurement, the research team experimentally proved that, unlike XPS, the thickness determination standard does not change with MEIS.

The MEIS equipment developed by a domestic small and medium-sized enterprise can analyze information about the composition, distribution, crystal structure, and thickness of nanometer-scale thin films with atomic layer depth resolution, making it applicable as measurement equipment for advanced device manufacturing processes including semiconductors.

MEIS was recognized as a new standard for nanofilm thickness measurement in a pilot study of the joint research by the Consultative Committee for Amount of Substance (CCQM) of the International Bureau of Weights and Measures (BIPM). Due to problems in determining the reference thickness by XPS, experts from national measurement standard institutions worldwide agreed to determine the reference thickness using MEIS.

Kim Kyung-jung, principal researcher at KRISS, said, “The core of this achievement is confirming the potential of domestically produced advanced measurement equipment capable of ultra-precise absolute thickness measurement of semiconductor oxide films.”

The research results were published in Applied Surface Science (IF: 6.182), a world-renowned journal in the field of measurement science.

This content was produced with the assistance of AI translation services.