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 (PureB-diodes)[1][2][3] 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) [4][5] has been achieved at a wavelength of 13.5 nm [3], which is the operating wavelength of the next-generation lithography systems [6]. Besides the outstanding optical performance stability already reported [3], 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.