Semiconductor device

Abstract

A transistor SEL is formed by using a compound semiconductor layer (channel layer CNL). The channel layer CNL is formed over a buffer layer BUF. In a first direction where a drain electrode DRE, a gate electrode GE, and a source electrode SOE of the transistor SEL are arranged, at least a portion of the buried electrode BE is situated on the side opposing the source electrode SOE with reference to the gate electrode GE. The buried electrode BE is connected to the source electrode SOE of the transistor SEL. The top end of the buried electrode BE intrudes into the buffer layer BUF.

1 - 8 . (canceled) 
     
     
         9 . A semiconductor device comprising:
 a substrate having a base layer, a buffer layer formed over the base layer, and a compound semiconductor layer formed over the buffer layer;   a first transistor with a first channel being formed in the compound semiconductor layer and having a first drain electrode, a first gate electrode, and a first source electrode,   the first drain electrode, the first gate electrode, and the first source electrode being arranged with respect to each other along a first direction and extending in a second direction perpendicular to the first direction;   a second transistor with a second channel being formed in the compound semiconductor layer and having a second drain electrode, a second gate electrode, and a second source electrode,   the second drain electrode, the second gate electrode, and the second source electrode being arranged with respect to each other along the first direction and extending in the second direction;   a buried electrode extending through a thickness of the compound semiconductor layer such that an end portion of the buried electrode protrudes into the buffer layer, the buried electrode being arranged on a side of the first gate electrode in the first direction opposite to the first source electrode and on a side of the second gate electrode in the first direction opposite to the second source electrode; and   a connection member electrically connecting the buried electrode and the first source electrode,   wherein a Schottky junction is formed at a lateral sidewall of the buried electrode contacting the compound semiconductor layer, and   wherein the buried electrode is adjacent to the first drain electrode and the second drain electrode.   
     
     
         10 . The semiconductor device according to  claim 9 , wherein a distance from the buried electrode to the first drain electrode in the first direction is less than a distance from the first drain electrode to the first gate electrode in the first direction. 
     
     
         11 . The semiconductor device according to  claim 9 , wherein the first drain electrode is arranged between the buried electrode and the first gate electrode in the first direction. 
     
     
         12 . The semiconductor device according to  claim 9 , wherein the first drain electrode connects to the second drain electrode, the first source electrode connects to the second source electrode, and the first gate electrode connects to the second gate electrode. 
     
     
         13 . The semiconductor device according to  claim 9 , wherein the compound semiconductor layer contains Ga and N, the buffer layer comprises a stack of AIN and GaN layers, and the end portion of the buried electrode protrudes into at least an uppermost AIN layer of the buffer layer.