Semiconductor device with Schottky layer

A semiconductor device comprising:

• a Schottky layer comprised of AlGaAs;
• a cap layer comprised of GaAs and that covers a surface of the Schottky layer, except for including a contact hole that is formed through the cap layer;
• and
• a Schottky electrode formed on the cap layer and connected to the Schottky layer through the contact hole,
• the Schottky electrode including an upper portion which has a first width and a lower portion which has a second width that is smaller than the first width, wherein the lower portion is located in the contact hole.

A semiconductor device comprising:

• a Schottky layer formed over a semiconductor substrate;
• a cap layer comprised of a semiconductor material and including a contact hole formed therethrough, the cap layer covering a surface of the Schottky layer;
• and
• a Schottky electrode formed on the cap layer and connected to the Schottky layer through the contact hole,
• the Schottky electrode including an upper portion which has a first width and a lower portion which has a second width that is smaller than the first width, wherein the lower portion is located in the contact hole and wherein the cap layer is contacted with the Schottky electrode.