Light Yields of Diamonds with Nitrogen-Vacancy Centers as Scintillators for Ionizing Radiation from 80 to 1200 eV

Abstract

The detection and imaging of extreme ultraviolet (EUV) radiation are crucial processes in modern photolithography for manufacturing advanced semiconductor chips. The discovery of diamonds containing nitrogen-vacancy (NV) centers as scintillators for this purpose is a significant development. These highly durable materials can emit red fluorescence from NV⁰ centers when exposed to EUV and even soft X-ray (SXR). However, precise measurements of their light yields (LYs), a critical parameter for scintillators, have been lacking in the research. By referencing the photoluminescence quantum yield of NV⁰ centers at 532 nm, this study fills the gap by measuring the absolute LYs of a 0.5 mm thick single-crystal diamond with an NV concentration of 0.3 ppm. The LYs are strongly related to how deep the radiation penetrates the material. They increase from 7.6 to 16.3 photons/keV as the photon energy varies from 80 to 1200 eV. A distinct drop at 285 eV, which corresponds to the K-shell absorption edge of carbon atoms, appears due to the shallow penetration of light. High-quality images of the radiations are also obtainable with the scintillator in a lens-coupled system. The findings establish a solid foundation for utilizing diamonds with various color centers as innovative scintillators for beam diagnostics of EUV/SXR in next-generation photolithography.