Semiconductor device
According to one embodiment, a semiconductor device includes a first electrode, a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type, a third semiconductor region of the second conductivity type, and a second electrode. The third semiconductor region is located on the second semiconductor region, and has a higher second-conductivity-type impurity concentration than the second semiconductor region. The second electrode is located on the third semiconductor region. The second electrode includes a first part and a second part. The first part is located in the second semiconductor region. The second part is positioned on the first part, and contacts the third semiconductor region in a second direction perpendicular to a first direction from the first electrode toward the first semiconductor region. A length of the first part is greater than a length of the second part in the second direction.
1 . A semiconductor device, comprising:
a first electrode;
a first semiconductor region located on the first electrode, the first semiconductor region being of a first conductivity type;
a second semiconductor region located on the first semiconductor region, the second semiconductor region being of a second conductivity type;
a third semiconductor region located on the second semiconductor region, the third semiconductor region being of the second conductivity type, a second-conductivity-type impurity concentration of the third semiconductor region being greater than a second-conductivity-type impurity concentration of the second semiconductor region; and
a second electrode located on the third semiconductor region, the second electrode including
a first part located in the second semiconductor region, and
a second part positioned on the first part, the second part contacting the third semiconductor region in a second direction perpendicular to a first direction, the first direction being from the first electrode toward the first semiconductor region,
a length in the second direction of the first part being greater than a length in the second direction of the second part.
2 . The device according to claim 1 , further comprising:
a conductive part facing the second semiconductor region via an insulating layer in the second direction,
the conductive part being electrically connected with the second electrode.
3 . The device according to claim 1 , further comprising:
a fourth semiconductor region located between a portion of the first electrode and a portion of the first semiconductor region, the fourth semiconductor region being of the second conductivity type;
a fifth semiconductor region located on the portion of the first semiconductor region, the fifth semiconductor region being of the second conductivity type;
a sixth semiconductor region located on the fifth semiconductor region, the sixth semiconductor region being of the first conductivity type; and
a gate electrode facing the fifth semiconductor region via a gate insulating layer in the second direction.
4 . The device according to claim 1 , wherein
the second electrode further includes a third part positioned between the first part and the second part,
the third part contacts the second semiconductor region in the second direction, and
a length of the third part in the second direction is equal to a length of the second part in the second direction.
5 . The device according to claim 1 , wherein
the first part includes a void.
6 . A semiconductor device, comprising:
a first electrode;
a first semiconductor region located on the first electrode, the first semiconductor region being of a first conductivity type;
a second semiconductor region located on the first semiconductor region, the second semiconductor region being of a second conductivity type; and
a second electrode located on the second semiconductor region, the second electrode including
a first part located in the second semiconductor region, and
a second part positioned on the first part,
a length of the first part in a second direction perpendicular to a first direction being greater than a length of the second part in the second direction,
the first direction being from the first electrode toward the first semiconductor region,
a Schottky junction being formed between the first part and the second semiconductor region.
7 . The device according to claim 6 , further comprising:
a conductive part facing the second semiconductor region via an insulating layer in the second direction,
the conductive part being electrically connected with the second electrode.
8 . The device according to claim 6 , further comprising:
a fourth semiconductor region located between a portion of the first electrode and a portion of the first semiconductor region, the fourth semiconductor region being of the second conductivity type;
a fifth semiconductor region located on the portion of the first semiconductor region, the fifth semiconductor region being of the second conductivity type;
a sixth semiconductor region located on the fifth semiconductor region, the sixth semiconductor region being of the first conductivity type; and
a gate electrode facing the fifth semiconductor region via a gate insulating layer in the second direction.
9 . The device according to claim 6 , wherein
the second electrode further includes a third part positioned between the first part and the second part,
the third part contacts the second semiconductor region in the second direction, and
a length of the third part in the second direction is equal to a length of the second part in the second direction.
10 . The device according to claim 6 , wherein
the first part includes a void.
11 . A semiconductor device, comprising:
a first electrode;
a first semiconductor region located on the first electrode, the first semiconductor region being of a first conductivity type;
a second semiconductor region located on the first semiconductor region, a second-conductivity-type impurity concentration of the second semiconductor region being not less than 1.0×10 16 atoms/cm 3 and not more than 1.0×10 18 atoms/cm 3 ; and
a second electrode located on the second semiconductor region, the second electrode including
a first part contacting the second semiconductor region, and
a second part positioned on the first part,
a length of the first part in a second direction perpendicular to a first direction being greater than a length of the second part in the second direction,
the first direction being from the first electrode toward the first semiconductor region.
12 . The device according to claim 11 , further comprising:
a conductive part facing the second semiconductor region via an insulating layer in the second direction,
the conductive part being electrically connected with the second electrode.
13 . The device according to claim 11 , further comprising:
a fourth semiconductor region located between a portion of the first electrode and a portion of the first semiconductor region, the fourth semiconductor region being of the second conductivity type;
a fifth semiconductor region located on the portion of the first semiconductor region, the fifth semiconductor region being of the second conductivity type;
a sixth semiconductor region located on the fifth semiconductor region, the sixth semiconductor region being of the first conductivity type; and
a gate electrode facing the fifth semiconductor region via a gate insulating layer in the second direction.
14 . The device according to claim 11 , wherein
the second electrode further includes a third part positioned between the first part and the second part,
the third part contacts the second semiconductor region in the second direction, and
a length of the third part in the second direction is equal to a length of the second part in the second direction.
15 . The device according to claim 11 , wherein
the first part includes a void.
16 . The device according to claim 6 , wherein
the second part is separated from the third semiconductor region in the second direction, and
a portion of the second semiconductor region is located between the second part and the third semiconductor region in the second direction.
17 . The device according to claim 11 , wherein
the second part is separated from the third semiconductor region in the second direction, and
a portion of the second semiconductor region is located between the second part and the third semiconductor region in the second direction.