Low‐cost growth of AlN using vectored‐flow epitaxy for the purpose of water sterilisation in a rural environment

Abstract

AbstractThe high V/III ratio required for the Metalorganic Chemical Vapour Deposition (MOCVD) growth of AlN using the precursors trimethylaluminium and ammonia have contributed to the excessive costs of producing ultra violet light emitting diodes (UVLEDs) which can be used in water purification. This paper introduces a novel growth technique, vectored‐flow epitaxy (VFE), which maintains the separation between gaseous reagents within the growth chamber. In addition, the VFE technique, which employs atmospheric pressure growth, also pre cracks the ammonia prior to injection and thereby significantly reduces the high V/III ratio required for the growth of this material. The pre cracked ammonia also removes the need for high growth temperatures, which is known to be necessary for its thermal decomposition. With this technique, 2 μm/h growth is possible at a V/III ratio of 50. These advances will contribute to the development of a cost‐effective solution to the treatment of drinking water in a rural environment. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)