Patent ID: 11908897
Assignee: KABUSHIKI KAISHA TOSHIBA
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. A semiconductor device, comprising:
a semiconductor layer of a first conductivity type;
a plurality of band-shaped regions extending in a first direction and being provided on the semiconductor layer;
a plurality of drain regions extending in the first direction, being provided on the semiconductor layer, being separated from the band-shaped regions, and being of a second conductivity type;
a gate insulating film provided in a region directly above a region of the semiconductor layer between one of the band-shaped regions and one of the drain regions;
a gate electrode extending in the first direction and being provided on the gate insulating film;
first contacts connected to the band-shaped regions; and
second contacts connected to the drain regions,
each of the band-shaped regions including
a back gate region of the first conductivity type, an impurity concentration of the back gate region being higher than an impurity concentration of the semiconductor layer, and
a source region of the second conductivity type, an impurity concentration of the source region being higher than the impurity concentration of the semiconductor layer,
each of the plurality of band-shaped regions and each of the plurality of drain regions being arranged alternately in a second direction in an element region,
a contact surface area between a second region and the first contacts being less than each of a contact surface area between a first region and the first contacts and a contact surface area between a third region and the first contacts when at least one of the band-shaped regions is subdivided into the first region, the second region, and the third region, when the second region is disposed between the first region and the third region in the first direction, and when a length of the first region, a length of the second region, and a length of the third region in the first direction are set to be equal to each other,
at least one first contact connected to the second region having a contact surface area smaller than each of at least one first contact connected to the first region and at least one first contact connected to the third region,
among the plurality of band-shaped regions, a contact surface area between the first contacts and one of the plurality of band-shaped regions most proximal to a central portion of the element region in the second direction being less than a contact surface area between the first contacts and one of the plurality of band-shaped regions disposed on an outermost side of the element region in the second direction, and
at least one first contact connected to the one of the band-shaped regions most proximal to the central portion having a contact surface area smaller than at least one first contact connected to the one of the band-shaped regions disposed on the outermost side.