A semiconductor device includes a semiconductor layer of a first conductivity type. A well region that is a second conductivity type well region is formed on a surface layer portion of the semiconductor layer and has a channel region defined therein. A source region that is a first conductivity type source region is formed on a surface layer portion of the well region. A gate insulating film is formed on the semiconductor layer and has a multilayer structure. A gate electrode is opposed to the channel region of the well region where a channel is formed through the gate insulating film.

A device is described herein. The device comprises a unit cell of a silicon carbide (SiC) substrate. The unit cell comprises: a trench in a well region having a second conduction type. The well region is in contact with a region having a first conduction type to form a p-n junction. A width of the trench is less than 1.0 micrometers (μm). A width of the unit cell is one of less than and equal to 5.0 micrometers (μm). The device comprises a source region comprising the first conduction type. The device further comprises a metal oxide semiconductor field effect transistor component. The device described herein comprises a reduced unit cell pitch and reduced channel resistance without any compromise in channel length. The device comprises an ILD opening greater than or equal to width of the trench.

Provided is a manufacturing method for a semiconductor device including forming a first electrode layer on a front surface of a wafer, implanting, into an outer peripheral region of the front surface of the wafer, a heavy ion of an element in third and subsequent rows of a periodic table, forming an oxide film in the outer peripheral region into which the heavy ion has been implanted, and forming a second electrode layer on the first electrode layer by plating. A dose of the heavy ion may be 1E15 cm.sup.−2 or more. A depth of an implantation range of the heavy ion into the wafer may be 0.02 μm or more. The heavy ion may be an As ion, a P ion, or an Ar ion.

A trench gate silicon carbide MOSFET with high reliability, including: An N+ type substrate, an N− type drift region, a first P type region, a P+ type contact region, an N+ type contact region, an N type equivalent resistance region between the first P type region and the N+ type contact region, a gate dielectric layer, a trench gate, an isolation dielectric layer, a source electrode and a drain electrode.

[Problem to be Solved] To provide a transistor and an electronic device whose characteristics are easier to control. [Solution] A transistor including: a semiconductor substrate; an insulating layer provided on the semiconductor substrate; a semiconductor layer provided on the insulating layer in a protruding manner; and a gate electrode provided over a portion of the insulating layer on the semiconductor layer and the insulating layer. A middle portion of a channel region of the semiconductor layer covered by the gate electrode is provided in a shape different from a shape of at least one of ends of the channel region of the semiconductor layer.

Provided is a first vertical field effect transistor in which first source regions and first connection portions via which a first body region is connected to a first source electrode are disposed alternately and cyclically in a first direction in which first trenches extend. In a second direction orthogonal to the first direction, Lxm≤Lxr≤0.20 μm holds true where Lxm denotes a distance between adjacent first trenches and Lxr denotes the inner width of a first trench. The lengths of the first connection portions are in a convergence region in which the on-resistance of the vertical field effect transistor at the time when a voltage having a specification value is applied to first gate conductors to supply current having a specification value does not decrease noticeably even when the lengths of the first connection portions are made much shorter.

A semiconductor device includes a semiconductor substrate and an electrode. The electrode is electrically connected to the semiconductor substrate and located on the semiconductor substrate. The electrode has a lower metal layer, an upper metal layer and an intermediate layer. The lower metal layer is located at a side closer to the semiconductor substrate. The upper metal layer is located above the lower metal layer. The intermediate layer is located between the lower metal layer and the upper metal layer. Each of the lower metal layer and the upper metal layer is made of aluminum or an aluminum alloy. In the aluminum alloy, an element is added to aluminum. The intermediate layer is made of material that is more difficult to react with a hydroxyl group than the lower metal layer and the upper metal layer.

The present disclosure relates to an electronic device comprising a semiconductor substrate and transistors having their gates contained in trenches extending in the semiconductor substrate, each transistor comprising a doped semiconductor well of a first conductivity type, the well being buried in the semiconductor substrate and in contact with two adjacent trenches among said trenches, a first doped semiconductor region of a second conductivity type, covering the well, in contact with the well, and in contact with the two adjacent trenches, a second doped semiconductor region of the second conductivity type more heavily doped than the first semiconductor region, extending in the first semiconductor region, and a third doped semiconductor region of the first conductivity type, more heavily doped than the well, covering the well, in contact with the first region, and extending in the semiconductor substrate in contact with the well.

A method for manufacturing a Laterally Diffused Metal Oxide Semiconductor (LDMOS) transistor with implant alignment spacers includes etching a gate stack comprising a first nitride layer. The first nitride layer is on a silicon layer. The gate stack is separated from a substrate by a first oxide layer. The gate stack is oxidized to form a polysilicon layer from the silicon layer, and to form a second oxide layer on a sidewall of the polysilicon layer. A drain region of the LDMOS transistor is implanted with a first implant aligned to a first edge formed by the second oxide layer. A second nitride layer is formed conformingly covering the second oxide layer. A nitride etch-stop layer is formed conformingly covering the second nitride layer.

A high voltage semiconductor device includes a semiconductor substrate, first and second deep well regions, and first and second well regions disposed in the semiconductor substrate. The second deep well region is located above the first deep well region. The first well region is located above the first deep well region. The second well region is located above the second deep well region. A conductivity type of the second deep well region is complementary to that of the first deep well region. A conductivity type of the second well region is complementary to that of the first well region and the second deep well region. A length of the second deep well region is greater than or equal to that of the second well region and less than that of the first deep well region. The first well region is connected with the first deep well region.