Electrical performance stability characterization of high-sensitivity Si-based EUV photodiodes in a harsh industrial application

Recently, silicon-based ultrashallow junction p⁺n photodiodes fabricated by pure boron CVD technology (Pure-Bdiodes) were evaluated for detection in the Extreme Ultra-Violet (EUV) spectral range spanning from 3 nm to 15 nm. A near-theoretical responsivity (0.265 A/W) has been achieved at a wavelength of 13.5 nm, which is the operating wavelength of the next-generation lithography systems. Besides the outstanding optical performance stability already reported, in this paper, the electrical performance stability of PureB-diodes is characterized. The experimental results show that the main reason for the increasing EUV-induced dark current is the radiation-caused damage along the Si-SiO₂ interface. However, this damage can be minimized by introducing a silicon nitride layer to the surface-passivation layer stack.