Imaging Extreme Ultraviolet Radiation Using Nanodiamonds with Nitrogen-Vacancy Centers

Extreme ultraviolet (EUV) radiation with wavelengths of 10-121 nm has drawn considerable attention recently for its use in photolithography to fabricate nanoelectronic chips. This study demonstrates, for the first time, fluorescent nanodiamonds (FNDs) with nitrogen-vacancy (NV) centers as scintillators to image and characterize EUV radiations. The FNDs employed are ∼100 nm in size; they form a uniform and stable thin film on an indium-tin-oxide-coated slide by electrospray deposition. The film is nonhygroscopic and photostable and can emit bright red fluorescence from NV⁰ centers when excited by EUV light. An FND-based imaging device has been developed and applied for beam diagnostics of 50 nm and 13.5 nm synchrotron radiations, achieving a spatial resolution of 30 μm using a film of ∼1 μm thickness. The noise equivalent power density is 29 μW/(cm² Hz^1/2) for the 13.5 nm radiation. The method is generally applicable to imaging EUV radiation from different sources.