HVPE-Grown AlN-GaN Based Structures for UV Spectral Region

Abstract

In this paper we describe ultraviolet light emitting diodes (LEDs) emitting in the spectral range from 305 to 340 nm based on AlGaN/AlGaN multi-layer submicron heterostructures grown by hydride vapor phase epitaxy (HVPE). The developed HVPE process possesses unique features such as ability (i) to combine deposition of thick low-defect layers and thin device multi-layer structures in the same growth run and (ii) to easily grow high-quality AlGaN layers in the whole composition range. HVPE is carbon-free growth technique producing GaN materials with very low background impurity concentrations. For a packaged LED with the peak wavelength of 340 nm, an optical output power of 2 mW was achieved at pulsed injection currents of 110 mA. The obtained results prove the developed HVPE technique to have a significant potential for production of device epitaxial wafers, particularly for fabrication AlGaN-based light emitters.