| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a contact resistance of an ohmic electrode. <P>SOLUTION: A semiconductor device comprises a second nitride semiconductor layer 14 formed on a first nitride semiconductor layer 13 and having a larger band gap than that of the first nitride semiconductor layer 13; and a recess of a shape penetrating through the second nitride semiconductor layer 14 and removing one part of the first nitride semiconductor layer 13; and an electrode 17 embedded into the recess. A two-dimensional electron gas layer 13a is provided immediately below an interface between the first nitride semiconductor layer 13 and the second nitride semiconductor layer 14. An electrode 17 comes into contact with the second nitride semiconductor layer 14 on a first contact surface 16a. The electrode 17 comes into contact with a portion of the two-dimensional electron gas layer 13a on a second contact surface 16b connected to a lower part of the first contact surface 16a. The first contact surface 16a has a shape such that width of the recess becomes larger upward from below. At a connecting portion, the second contact surface 16b is steeper relative to an upper face of the first nitride semiconductor layer 13 than the first contact surface 16a. <P>COPYRIGHT: (C)2012,JPO&INPIT |
