A vertical AlGaN DUV light-emitting diode fabricated by wafer bonding and sapphire thinning technology

Abstract

We demonstrate a vertical AlGaN DUV LED with an emission wavelength of 272 nm and submicron thickness. The device epilayers’ thickness is reduced to ∼670 nm by a combination of wafer bonding and thinning techniques, and this results in the thinnest vertical DUV LED reported to date. A light-emitting surface with a root mean square value of 74.7 nm is also induced by the thinning process without any other surface-roughing treatments. An n-contact electrode with a mesh geometry is adopted to expose the emission region, while the bottom metal electrode functions as a reflector to reflect downward-propagating light in an upward direction.