Gallium nitride based semiconductor device and method of manufacturing same

A gallium nitride based semiconductor device comprising:

• a first gallium nitride based semiconductor film doped with magnesium;
• and
• a second gallium nitride based semiconductor film provided on the first gallium nitride based semiconductor film and doped with magnesium,
• the first gallium nitride based semiconductor film having substantially flat distributions of magnesium concentration and hydrogen atom concentration, and the magnesium concentration being higher than the hydrogen atom concentration, and
• the second gallium nitride based semiconductor film having a first region in which the magnesium concentration and the hydrogen atom concentration increase toward a surface, and the magnesium concentration in the first region being higher than the hydrogen atom concentration in the first region and higher than the magnesium concentration in the first gallium nitride based semiconductor film.

A method of manufacturing a gallium nitride based semiconductor device comprising:

• growing a first gallium nitride based semiconductor film doped with magnesium by using a metal organic chemical vapor deposition method and feeding a carrier gas containing hydrogen more than nitrogen;
• temporarily interrupting supply of a group III source gas after growing the first gallium nitride based semiconductor film;
• and
• growing a second gallium nitride based semiconductor film doped with magnesium on the first gallium nitride based semiconductor film by using the metal organic chemical vapor deposition method and feeding a carrier gas containing nitrogen more than hydrogen.