Method for manufacturing semiconductor device and semiconductor device

A semiconductor device comprising:

• a SiC substrate;
• a nitride semiconductor layer provided on a main surface of the SiC substrate;
• a first source electrode, a second source electrode adjacent to the first source electrode, and a drain electrode provided on the nitride semiconductor layer;
• a gate electrode provided between the first source electrode and the drain electrode on the nitride semiconductor layer;
• a first metal film provided only in a region between the first source electrode and the second source electrode with an interval therebetween on the nitride semiconductor layer;
• an insulating film provided on the first metal film and the first source electrode and the second source electrode, and provided between the first metal film and the first source electrode and between the first metal film and the second source electrode;
• a second metal film electronically connected to the first source electrode and the second source electrode, and the first metal film, the second metal film being provided over the insulating film;
• and
• a metal via provided in a hole of the SiC substrate, the metal via being continuous from a back surface of the SiC substrate to the first metal film.

A semiconductor device comprising:

• a SiC substrate;
• a nitride semiconductor layer provided on a main surface of the SiC substrate;
• a first source electrode, a second source electrode adjacent to the first source electrode, and a drain electrode provided on the nitride semiconductor layer;
• a gate electrode provided between the first source electrode and the drain electrode on the nitride semiconductor layer;
• a first metal film provided in a region between the first source electrode and the second source electrode with an interval therebetween on the nitride semiconductor layer;
• an insulating film provided on the first metal film and the first source electrode and the second source electrode, and provided between the first metal film and the first source electrode and between the first metal film and the second source electrode;
• a second metal film electronically connected to the first source electrode and the second source electrode, and the first metal film, the second metal film being provided over the insulating film;
• and
• a metal via provided in a hole of the SiC substrate, the metal via being continuous from a back surface of the SiC substrate to the first metal film,
• wherein the gate electrode has a laminated structure including a Ni layer and an Au layer on the Ni layer, and
• wherein the first metal film has a same laminated structure as the gate electrode.

A method for manufacturing a semiconductor device, the method comprising:

• forming a first source electrode, a second source electrode adjacent to the first source electrode, and a drain electrode on a nitride semiconductor layer formed on a main surface of a SiC substrate;
• forming a gate electrode between the first source electrode and the drain electrode on the nitride semiconductor layer;
• forming a first metal film in a region between the first source electrode and the second source electrode with an interval therebetween;
• forming an insulating film in the interval;
• forming a second metal film over the insulating film, the second metal film being electronically connected between the first source electrode, the second source electrode, and the first metal film;
• forming a hole being continuous with the first metal film from a back surface of the SiC substrate;
• and
• forming a metal via being continuous with the first metal film from the back surface in the hole,
• wherein the gate electrode is formed to have a laminated structure including a Ni layer and an Au layer on the Ni layer, and
• wherein the first metal film is formed to have a same laminated structure as the gate electrode.