摘要：The group Ⅲ nitrides are an important class of materials with aplications in UV and visible optoelectronics,high temperature electronics,cold cathodes and solar blind *** recent years,with the realisation of nitride based LEDs,the use of GaN IED has the potential to compete with 1raditional filament and discharge lamps,for the provision of white lighting,and there has been an explosion of interest in the MOcVD growth of GaN based materials with an increasing focus on large area multiwafer reactors and wafer *** paper will review the design philosophy and characteristics of close-coupled showerhead reactors,relating these to the requirements of group Ⅲ-nitride growth,and will present a selection of data resulting from the operation of such *** results suggest that the close coupled showerhead style of reactor is very suitable for the growth of GaN based structures in both research and production environments.