Influence of the Thin-Film Ag Electrode Deposition Thickness on the Current Characteristics of a CVD Diamond Radiation Detector

Abstract

Background:We investigated the current characteristics of a thin-film Ag electrode on a chemical vapor deposition (CVD) diamond. The CVD diamond is widely recognized as a radiation detection material because of its high tolerance against high radiation, stable response to various dose rates, and good sensitivity. Additionally, thin-film Ag has been widely used as an electrode with high electrical conductivity. Materials and Methods:Considering these properties, the thin-film Ag electrode was deposited onto CVD diamonds with varied deposition thicknesses (≒50/98/152/257 nm); subsequently, the surface thickness, surface roughness, leakage current, and photo-current were characterized. Results and Discussion:The leakage current was found to be very low, and the photo-current output signal was observed as stable for a deposited film thickness of 98 nm; at this thickness, a uniform and constant surface roughness of the deposited thin-film Ag electrode were obtained. Conclusion:We found that a CVD diamond radiation detector with a thin-film Ag electrode deposition thickness close to 100 nm exhibited minimal leakage current and yielded a highly stable output signal. JRPRScience and ICT (MSIT) of Republic of Korea.