GaN-based ultraviolet (UV) photodetectors were fabricated with transparent TiN electrodes. It was found that the transmittance was higher than 80% for a 50-nm-thick TiN layer. It was also found that we can significantly reduce the dark current of the photodetectors by inserting a thin Ba 0:25 Sr 0:75 TiO 3 (BST) interlayer between the TiN electrode and the n-GaN. With a 3-nm-thick BST interlayer, we can realize a TiN/BST/GaN photodetector with a photocurrent-to-dark current contrast as high as 2:5 Â 10 4 .
Reactive ion etching (RIE) of GaN has been performed using BCl3 and additives Ar, CH4, and N2 to BCl3 plasma. The etching rate, surface roughness and the etch profile have been investigated. When BCl3/Ar was used as the RIE plasma source with 200 W RF power and 60 mTorr pressure, the highest etching rates of 505 Å/min and 448 Å/min were obtained for n- and p-GaN, respectively. It was found that the addition of CH4 and N2 to the BCl3 plasma would result in significant changes of the etching results, such as the etching rate and surface morphology. It was also found that with the proper etching parameter, the mirrorlike facet of GaN can be obtained using BCl3/Ar/CH4/N2 by RIE.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.