Molecular beam epitaxy method

摘要

An epitaxial deposit of GaN is formed on a substrate S by molecular beam epitaxy. The substrate S is located in a vacuum chamber 10 containing a heated support 12 for the substrate S. The chamber 10 is fitted with an exhaust conduit 16 and connected with an ultra high vacuum pump 14. An ammonia supply conduit 20 is adjustably mounted in the chamber 10. The inner end of the exhaust conduit 16 defines an exhaust outlet 18 of the chamber 10, whilst the first supply conduit 20 has an ammonia outlet 22 opening into the chamber 10. The outlet 22 and the vacuum outlet 18 are disposed adjacent the substrate S. The ammonia outlet 22 of the first supply conduit 20 is disposed nearer to the substrate S than those of conventionally positioned effusion cells 24 and 26 defining second and further supply conduits respectively for gallium and another elements to be supplied in elemental form to the vacuum chamber 10.