Novel Epitaxy for Nitride Semiconductors Using Plasma Technology.

For the production of nitride‐based optical and power devices, it is known that metal organics chemical vapor deposition (MOCVD) is an industrial method which is used worldwide. However, MOCVD has disadvantages: 1) a lot of ammonia gas is consumed; 2) the sublimation of GaN is not negligible at growth temperature and these increase the production cost; 3) the growth of in‐containing nitrides is difficult because the growth temperature is too high; and 4) using large Si substrates of 150–300 mm diameter for industrial production, wafer breakage and bowing occur. It is therefore important to develop novel epitaxial growth methods that can replace the MOCVD method. Recently, high‐density radical source (HDRS) is developed by combining inductively coupled plasma (ICP) and capacitively coupled plasma (CCP) which can be applied to molecular beam epitaxy (MBE) in order to increase the growth rate of nitrides. Another novel method, the radical enhanced MOCVD (REMOCVD) method with using very high frequency (VHF) plasma, has also been developed. This REMOCVD allows the low growth temperature without using any ammonia gas. These novel methods are promising for replacing the MOCVD method from the viewpoint of production cost without ammonia gas usage. [ABSTRACT FROM AUTHOR]