COMPOUND SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME
A gate electrode is formed above a compound semiconductor stacked structure, and the gate electrode includes a stack of a TaN:Al layer in which Al is solid-dissolved in TaN, a TaAlN layer made of a compound of TaN and Al, and an Al layer.
1 . A compound semiconductor device comprising:
a compound semiconductor stacked structure; and
an electrode formed above the compound semiconductor stacked structure, the electrode comprising:
a first electrode layer having a first low-resistance metal; and
a second electrode layer disposed between the compound semiconductor stacked structure and the first electrode layer and having a first nitride conductor in which a second low-resistance metal is solid-dissolved.
2 . The compound semiconductor device according to claim 1 , wherein the electrode further comprises a third electrode layer disposed between the first electrode layer and the second electrode layer and having a compound of a second nitride conductor and a third low-resistance metal.
3 . The compound semiconductor device according to claim 1 , wherein the first low-resistance metal and the second low-resistance metal are the same.
4 . The compound semiconductor device according to claim 1 , wherein the first nitride conductor and the second nitride conductor are the same.
5 . The compound semiconductor device according claim 1 , further comprising
a protective insulating film formed on the compound semiconductor stacked structure and having an opening whose side surface is in a forward tapered shape,
wherein the electrode fills an inside of the opening and is formed on the protective insulating film.
6 . A method of manufacturing a compound semiconductor device comprising:
forming a compound semiconductor stacked structure; and
forming an electrode above the compound semiconductor stacked structure, the electrode comprising:
a first electrode layer having a first low-resistance metal; and
a second electrode layer disposed between the compound semiconductor stacked structure and the first electrode layer and having a first nitride conductor in which a second low-resistance metal is solid-dissolved.
7 . The method of manufacturing the compound semiconductor device according to claim 6 , wherein the electrode further comprises a third electrode layer disposed between the first electrode layer and the second electrode layer and having a compound of a second nitride conductor and a third low-resistance metal.
8 . The method of manufacturing the compound semiconductor device according to claim 6 , wherein the first low-resistance metal and the second low-resistance metal are the same.
9 . The method of manufacturing the compound semiconductor device according to claim 6 , wherein the first nitride conductor and the second nitride conductor are the same.
10 . The method of manufacturing the compound semiconductor device according to claim 6 , further comprising
forming a protective insulating film having an opening whose side surface is in a forward tapered shape, on the compound semiconductor stacked structure,
wherein the electrode fills an inside of the opening and is formed on the protective insulating film.
11 . A power supply circuit comprising:
a transformer; and
a high-voltage circuit and a low-voltage circuit sandwiching the transformer, the high-voltage circuit comprising
a transistor; the transistor comprising:
a compound semiconductor stacked structure; and
an electrode formed above the compound semiconductor stacked structure, the electrode comprising:
a first electrode layer having a first low-resistance metal; and
a second electrode layer disposed between the compound semiconductor stacked structure and the first electrode layer and having a first nitride conductor in which a second low-resistance metal is solid-dissolved.