Method of fabricating a high electron mobility transistors, field effect transistors, the epitaxial substrate, a method and a Group III nitride transistor for producing an epitaxial substrate

摘要

PROBLEM TO BE SOLVED: To provide a high electron mobility transistor having a channel layer of a high purity and a buffer layer of a high resistance.;SOLUTION: The high electron mobility transistor 11 comprises a support substrate 13 made of gallium nitride; a buffer layer 15 composed of a first gallium nitride based semiconductor; a channel layer 17 composed of a second gallium nitride based semiconductor; a semiconductor layer 19 composed of a third gallium nitride based semiconductor; and an electrode structure (a gate electrode 21, a source electrode 23 and a drain electrode 25) for the corresponding transistor 11. The band gap of the third gallium nitride based semiconductor is greater than the second gallium nitride based semiconductor. A carbon concentration Nc₁ of the first gallium nitride based semiconductor is not less than 4×10¹⁷ cm^-3, and the concentration N_C2 of the second gallium nitride based semiconductor is less than 4×10¹⁶ cm^-3.;COPYRIGHT: (C)2007,JPO&INPIT