Patent ID: 9166030
Filing Date: 2015-10-20
Classification: H01L,H03F

Abstract:
1. A method for fabricating a compound semiconductor device, the method comprising: forming a first compound semiconductor, a second compound semiconductor that has a lattice constant smaller than the lattice constant of the first compound semiconductor, and a third compound semiconductor that has a lattice constant greater than the lattice constant of the second compound semiconductor, on a surface of a substrate, in such a manner that the first, second and third compound semiconductors have an opening; forming a fourth compound semiconductor in contact with a whole side surface which is an inner wall of the opening, the fourth compound semiconductor having a lattice constant smaller than the lattice constants of the first compound semiconductor and the third compound semiconductor; forming an insulating film to cover the inner wall surface of the opening; forming a gate electrode to fill the opening lined with the insulating film; and forming a first electrode below the first compound semiconductor and forming a second electrode above the third compound semiconductor, wherein a two-dimensional electron gas is produced in a vertical direction to the surface of the substrate at an interface of the first compound semiconductor with the fourth compound semiconductor and at an interface of the third compound semiconductor with the fourth compound semiconductor.