Highly sensitive visible-blind extreme ultraviolet Ni/4H-SiC Schottky photodiodes with large detection area

Abstract

$\mathrm{Ni}∕4\mathrm{H}\text{-}\mathrm{Si}\mathrm{C}$ Schottky photodiodes of $5\mathrm{mm}\times 5\mathrm{mm}$ area have been fabricated and characterized. The photodiodes show less than $0.1\mathrm{pA}$ dark current at $-4\mathrm{V}$ and an ideality factor of 1.06. A quantum efficiency (QE) between 3 and $400\mathrm{nm}$ has been calibrated and compared with Si photodiodes optimized for extreme ultraviolet (EUV) detection. In the EUV region, the QE of SiC detectors increases from $0.14\text{\hspace{0.17em} electrons}$/photon at $120\mathrm{nm}\text{to}30\text{\hspace{0.17em} electrons}$/photon at $3\mathrm{nm}$. The mean energy of electron-hole pair generation of 4H-SiC estimated from the spectral QE is found to be $7.9\mathrm{eV}$.