High-Performance 4H-SiC EUV Photodiode With Lateral p-n Junction Fabricated by Selective-Area Ion Implantation

In this work, a 4H-SiC EUV photodiode (PD) with lateral p-n junction formed by selective-area ion implantation is investigated, in which grid-shaped p-type contact region is designed for enhancing effective EUV light absorption. The large area SiC PD with 9 mm diameter exhibits a low dark current density of <inline-formula> <tex-math notation="LaTeX">$\sim 9$ </tex-math></inline-formula> pA/cm2 and a high responsivity of 0.07 A/W at 13.5 nm under 5 V reverse bias. The detectivity of PD is further determined to be <inline-formula> <tex-math notation="LaTeX">$\sim {5}.{9}\times {10} ^{{12}}$ </tex-math></inline-formula> cmHz<inline-formula> <tex-math notation="LaTeX">$^{{0}.{5}}\text{W}^{-{1}}$ </tex-math></inline-formula> based on 1/f noise test. Two-dimensional photocurrent mapping of photosensitive area indicates that the non-uniformity of photo-responsivity at 13.5 nm is less than 0.67%. When tested by using a 266 nm pulse laser, the PD shows a fast rise time of ~4.3 ns in transient response measurement. The PD also exhibits low dark current, stable capacitance and responsivity at elevated temperatures up to 150 °C, suggesting that the detector has good potential for high-temperature operation.