Kabushiki Kaisha Toshiba

Noboru Matsuda

Yoshiro Baba

Satoshi Yanagiya

Akihiko Osawa

Masanobu Tsuchitani

Hideyuki Ura

Kouta Tomita

Yasuo Ebuchi

Hitoshi Kobayashi

Keiko Kawamura

Hideki Okumura

Hironobu Shibata

Masaru Kawakatsu

Shoji Takayama

In general, according to one embodiment, a semiconductor device includes a first electrode, a first and a second semiconductor layer of a first conductivity type, a third semiconductor layer of a second conductivity type, a fourth semiconductor layer of the first conductivity type in this order. A device region includes a gate electrode inside a first trench. A second trench having a ring-shaped structure forms a first region penetrating through the fourth and third semiconductor layers to the second semiconductor layer and including the device region inside and a second region surrounding the first region outside. A first opening is provided between adjacent ones of the first trenches. A second opening having a wider width than the first opening is provided in the first region outside the device region. A second electrode is electrically connected to the third and fourth semiconductor layers through the first and second openings.

Semiconductor device

According to one embodiment, a semiconductor device includes a first semiconductor layer of a first conductivity type, a second semiconductor layer, a third semiconductor layer, a fourth semiconductor layer, first trenches, a second trench, an insulating film, a gate electrode, a first main electrode, a second main electrode, a channel stopper layer and a channel stopper electrode. The second semiconductor layer of the first conductivity type is provided on the first semiconductor layer. The third semiconductor layer of a second conductivity type is provided on the second semiconductor layer. The fourth semiconductor layer of the first conductivity type is provided on the third semiconductor layer. The gate electrode is provided in the first trenches via the insulating film. The first main electrode is provided on the first semiconductor layer. The second main electrode is provided to contact the element part. The channel stopper electrode is provided on the termination part.

Semiconductor device and method for manufacturing the same

A semiconductor device comprises: a first semiconductor region of a first conductivity type; a second semiconductor region of a second conductivity type provided on the first semiconductor region; a trench formed in the second semiconductor region; a thick gate insulating film selectively provided in a center area of a bottom surface of the trench; a thin gate insulating film provided along a periphery of the bottom surface and on a sidewall of the trench; a third semiconductor region of the first conductivity type that is selectively provided below the thin gate insulating film provided along the periphery of the bottom surface of the trench and that extends to the first semiconductor region; a fourth semiconductor region of the first conductivity type selectively provided in the surface of the second semiconductor region; and a gate electrode filling the trench via the gate insulating film.

Trench gate semiconductor device with a reduction in switching loss

A semiconductor device, and particularly an MOS transistor device, wherein in order to increase a channel region density and to achieve a low resistance of a transistor device there is provided a first gate electrode group having a plurality of gate electrodes formed on a semiconductor substrate to be away from each other at first equal spacings, a second gate electrode group having a plurality of gate electrodes formed on the semiconductor substrate to be away from each other at the first equal spacings, a source contact portion formed away from the first or the second gate electrode group at a second spacing, and source regions for electrically interconnecting the first gate electrode group and the source contact. The source regions are connected to each other at one end of the first gate electrode group, and separated at the other end of the first gate electrode group. In addition, the gate electrodes of the first group are connected each other at the other end. The second spacing is greater than the first spacing.

Power MOS transistor having trench gate

A power semiconductor device comprises a semiconductor layer; a polysilicon-containing gate; a first semiconductor region formed in said semiconductor layer at one surface of said semiconductor layer and operative to serve as at least one of a source region and an emitter region; a second semiconductor region formed in said semiconductor layer at the other surface of said semiconductor layer and operative to serve as at least one of a drain region and a collector region; a gate routing wire commonly connected to a plurality of said gates and including a polysilicon portion and a metal portion formed adjacent to it in the direction of plane of said semiconductor layer; an interlayer insulator film formed to cover said first semiconductor region, said gate routing wire and a plurality of said gates; an electrode portion formed in said interlayer insulator film and connected to said first semiconductor region; and a strap electrode plate located to cover said interlayer insulator on said gate routing wire and cover a plurality of said electrode portions and commonly connected to a plurality of said electrode portions.

Power semiconductor device

A semiconductor device comprises: a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type; a trench; a thick gate insulating film; a thin gate insulating film; a gate electrode; and a semiconductor region of a second conductivity type. The second semiconductor layer is provided on the first semiconductor layer. The trench penetrates the second semiconductor layer and intrudes into the first semiconductor layer. The thick gate insulating film is provided on a inner wall of the trench below an upper surface of the first semiconductor layer. The thin gate insulating film is provided on the inner wall of the trench at a part upper than the thick gate insulating film. The gate electrode fills the trench. The semiconductor region of a second conductivity type is selectively formed to adjoin the trench and to project from a bottom surface of the second semiconductor layer into the first semiconductor layer.

Semiconductor device having a trench-gate structure

There is provided a semiconductor device comprising a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type formed on the first semiconductor layer, the second conductivity type being different from the first conductivity type, a third semiconductor layer of the first conductivity type selectively formed on the second semiconductor layer, a trench formed through the third semiconductor layer and the second semiconductor layer to reach the first semiconductor layer, a gate dielectric film formed along side and bottom surfaces of the trench, and a gate electrode formed to be in contact with the gate dielectric film at the side surfaces of the trench, surfaces of the gate electrode that are opposite to the surfaces contacting the gate dielectric film, and the gate dielectric film at a bottom of the trench forming a hollow portion extending from the bottom to an opening side of the trench.

Semiconductor device and method of manufacturing the same

A semiconductor device is characterized in that source electrode contact regions, each of which is formed of a first conductivity type source layer and a second conductivity type base layer in a surface of a semiconductor surface, are formed at respective intersectional points of a diagonally-arranged lattice, and in that a trench having a gate electrode buried therein is formed so as to snake through the contact regions alternately. By virtue of the structure, the trench arrangement and source/base simultaneous contact quality are improved, to thereby increase a trench density (channel density) per unit area.

The present invention relates to a schottky-barrier diode capable of decreasing a leakage current due to damage generated on inner walls of trenches, and securing a large operation region for itself. In the device, an N.sup.- -type epitaxial layer is formed on a N.sup.+ -type silicon substrate. In a predetermined region in the epitaxial layer, a P.sup.+ -type base diffusion layer having high impurity concentration is formed. Trenches are formed through from the surface of the base diffusion layer to the epitaxial layer. In each of the trenches, an N.sup.- -type selective epitaxial growth region is formed. A schottky metal is formed on a surface comprising the surfaces of the base diffusion layer, which includes the selective epitaxial growth regions, and the epitaxial layer. Surface regions as the surfaces of the selective epitaxial growth regions filling the trenches function as diode operation regions.

Trench-type schottky-barrier diode

In a vertical field effect transistor having a trench gate and a method of manufacturing the same according to the present invention, p-type base and n.sup.+ -type source diffusion layers are formed in this order in a surface region of an n.sup.31 -type epitaxial layer on an n.sup.+ -type semiconductor substrate. A trench is then provided to such a depth as to penetrate the diffusion layers. A dope polysilicon layer is deposited and buried into the trench with a gate insulation film interposed between them. The polysilicon layer is etched to have the same level as that of the entrance of the trench, and a dope polysilicon layer 18 is selectively grown thereon, thereby forming a trench gate in which an upper corner portion of the trench is not covered with a gate electrode. Consequently, the concentration of electric fields at the corner portion can be mitigated thereby to increase an absolute withstand voltage of the gate and the variations in threshold voltage can be suppressed in a BT test.

Method for manufacturing a vertical transistor having a trench gate

In a vertical power MOSFET having a U-shaped trench gate and a method of manufacturing the same, a P-type base layer and an N.sup.+ -type emitter layer are formed on the surface of an N-type semiconductor substrate. A plurality of trenches are formed to such a depth as to reach the semiconductor substrate. After that, an oxide film and a nitride film are formed in this order on the surface of the resultant element and on the inner surfaces of the trenches. In this case, the oxide film and nitride film are each formed to have a thickness corresponding to the operating characteristics of the element at the stage of design. The nitride film of a gate wiring region is selectively removed to form an oxide film on the surface of the element. Consequently, a thick gate insulation film of the oxide films can be formed between the corner portions of the N.sup.+ -type emitter layer and a gate electrode wiring layer of the gate wiring region which is to be formed afterward, and the gate-to-source breakdown voltage can be enhanced.

Method of manufacturing a semiconductor device having a buried insulated

Semiconductor device having a buried insulated gate

A channel region and a source region are formed on a surface of a substrate by double diffusion. A trench is formed so as to penetrate a part of the channel region and a part of the source region and reach the substrate. After an insulating film is formed on an inner wall of the trench, a polysilicon layer is buried up to an intermediate portion of the trench. In this state, channel ions are implanted in a side surface region of the trench, thereby depleting a channel region. Thereafter, a polysilicon layer for leading out a gate is buried in the trench.

Growing community of inventors

Kanagawa, Japan

Noboru Matsuda