Kabushiki Kaisha Toshiba

Tokuda Seisakusho Co., Ltd.

Akihiko Osawa

Yoshiro Baba

Masanobu Tsuchitani

Satoshi Yanagiya

Yutaka Koshino

Hideki Okumura

Hitoshi Kobayashi

Shunichi Hiraki

Noboru Matsuda

Shizue Hori

Mitsuhiko Kitagawa

Tetsujiro Tsunoda

Wataru Saito

Ichiro Omura

Satoshi Aida

Masakazu Yamaguchi

Masaru Izumisawa

Shigeo Kouzuki

Shigeo Yawata

Kenji Yamawaki

Masaru Kawakatsu

Keita Suzuki

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 semiconductor device includes a diffusion area formed in a semiconductor layer of a first conductive type. The diffusion area comprises first and second impurity diffusion areas of the first and second conductive types, respectively. The diffusion area has a first and second areas which are defined by an impurity concentration of the first and second impurity diffusion areas. A junction between the first and second area is formed in a portion in which the first and second impurity diffusion areas overlap each other. A period of the impurity concentration, in a planar direction of the semiconductor layer, of the first or second area is smaller than the maximum width, in the planar direction of the semiconductor layer, of the first and second impurity diffusion areas constituting the first or second area.

Semiconductor device having vertical metal insulator semiconductor transistors having plural spatially overlapping regions of different conductivity type

A semiconductor device which comprises a semiconductor substrate, semiconductor pillar regions each having first and second semiconductor pillar portions, the second semiconductor pillar portion being sandwiched by the first semiconductor pillar portions, a base layer formed in the second semiconductor pillar portion, a source diffusion layer formed in the base layer, a gate insulating film formed on a portion of the base layer, a gate electrode formed on the gate insulating film, and isolation regions which isolates the semiconductor pillar regions from each other and are formed in trenches between the semiconductor pillar regions, wherein each of the isolation regions comprises an oxide film formed on an inner surface of the trench and a nitride film formed on the oxide film, the nitride film being filled in the trench, and a film thickness ratio of the oxide film and the nitride film is in a range of 2:1 to 5:1.

Semiconductor device

Formed in a part of the base region is an impurity diffusion region extending in a vertical direction and having an impurity concentration lower than that in the other portion of the base region. By the formation of the impurity diffusion region, the depletion layer is extended toward the base region so as to improve the breakdown voltage. The impurity diffusion region is formed by forming a trench in a part of the base region, a conductive film being buried in the trench, followed by introducing by ion implantation an impurity of the conductivity type equal to that in the base region into the side wall and the bottom of the trench in a concentration lower than that in the base region and subsequently diffusing the implanted impurity ions. The impurity diffusion region thus formed permits relaxing the electric field concentration on the corner portion of the gate trench and on the extended portion of the base region so as to improve the breakdown voltage.

Semiconductor device and method of manufacturing the same

A semiconductor device, which can have a uniform film on open ends of trenches by using materials having a different oxidation rate, and a fabrication method thereof are provided. The semiconductor device having trenches configured to have open ends covered with an oxidation film made of a material having an oxidation rate faster than that of a semiconductor substrate and a fabrication method thereof are provided.

Semiconductor gate trench with covered open ends

The main characteristic feature of the invention is to prevent a leakage current from flowing when a planar type semiconductor device having a high breakdown voltage is reverse-biased. For example, a semiconductive film is formed on the surface of an n-type Si substrate between a second p-type base layer selectively formed on the surface of the Si substrate and a channel stop layer formed to surround the second p-type base layer at a predetermined interval. The dangling bond density of the semiconductive film is set at 1.25.times.1018 cm.sup.-3. With this structure, the discrete level in the band gap approach a continuum, and the time required to populate the trapping level in the semiconductive film with carriers is shortened.

Power device having high breakdown voltage and method of manufacturing

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.

A semiconductor device includes a plurality of defect layers separated from one another in the semiconductor layer. A distance separating any adjacent ones of the defect layers is kept such that they are prevented from contacting each other and those regions having effect of shortening a carrier lifetime overlap each other.

Semiconductor device and method of manufacturing the same with stable

The most distinctive feature of the present invention lies in that a warp and crystal defects can be prevented from occurring and a processing margin for forming an isolation groove can be improved in an intelligent power device including a power element section and an IC control section within one chip. A bonded wafer is obtained by bonding an active-layer substrate and a supporting substrate with an epitaxially grown silicon layer interposed therebetween so as to cover an oxide film selectively formed at the interface of the active-layer substrate. Isolation trenches are then formed in the bonded wafer to such a depth as to reach the oxide film from the element forming surface of the active-layer substrate. Thus, an IC controller is formed within a dielectric isolation region surrounded with the isolation trenches and the oxide film and accordingly the IC controller can effectively be isolated by a dielectric.

Method of manufacturing semiconductor bonded substrate

The object of the present invention is to provide a method of manufacturing high-performance, high-breakdown-voltage semiconductor devices which suppresses an increase in the junction leakage current due to heavy metal contamination without increasing the number of manufacturing steps. A method of manufacturing semiconductor devices according to the invention, comprises the steps of ion-implanting one or more elements selected from a group of silicon, carbon, nitrogen, oxygen, hydrogen, argon, helium, and xenon into at least one surface of a semiconductor substrate of a first conductivity type at a dose of 1.times.10.sup.15 cm.sup.-2 or more to form a distortion layer, oxidizing the surface of the substrate to form an oxide film, ion-implanting impurities of a second conductivity type at a low concentration (a dose of less than 1.times.10.sup.15 cm.sup.-2) via the oxide film into the one surface of the substrate, ion-implanting impurities of the second conductivity type at a high concentration (a dose of 1.times.10.sup.15 cm.sup.-2 or more) via the oxide film into the other surface of the substrate, and forming a junction by heat treatment.

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.

Vertical power MOSFET and process of fabricating the same

In a semiconductor device including a composite substrate formed by bonding first and second semiconductor substrates to each other through an oxide film and an insulator isolation trench formed from a major surface of the first semiconductor substrate to reach the oxide film and to surround an element forming region, when the potential of the second substrate is set at a potential higher than the minimum potential in the element forming region of the first substrate, an breakdown voltage can be increased. In a semiconductor integrated circuit having an element isolation region, a semiconductor device of a perfect dielectric isolation structure having an element forming region having a thickness smaller than that of the element forming region of a P-N junction isolation structure is used to reduce, e.g., a base curvature influence, thereby obtaining a further high breakdown voltage.

Semiconductor device and method of increasing device breakdown voltage

A mixture of at least two types of charged particles of ions having the same value obtained by dividing the electric charge of an ion by the mass of the ion, i.e., a mixture of charged particles including hydrogen molecular ions H.sub.2.sup.+ and deuterium ions D.sup.+, is accelerated in a charged particle accelerator. Since the mass spectrograph unit in the accelerator cannot divide the hydrogen molecular ions H.sub.2.sup.+ and the deuterium ion D.sup.+, both ions are accelerated together. When the hydrogen molecular ion H.sub.2.sup.+ collides against a silicon substrate, it is divided into two hydrogen ions 2H.sup.+. Since the hydrogen ion H.sup.+ and the deuterium ion D.sup.+ have different ranges in silicon, two regions including a great number of crystal defects are formed in the silicon substrate in one ion irradiating step. As a result, at least three regions of different lifetimes of carriers are formed at different depths of the semiconductor substrate.

Method of manufacturing a semiconductor device by forming at least three

A vertical MOS transistor comprises a semiconductor substrate, a first impurity region defined on the surface of the semiconductor substrate, a second impurity region defined under the first impurity region, the conduction type of the second impurity region being opposite to that of the first impurity region, a trench engraved on the surface of the semiconductor substrate to cut through the first and second impurity regions deeper than at least the bottom of the second impurity region, and a gate electrode disposed in the trench with a gate insulation film interposing between the wall of the trench and the gate electrode. The gate insulation film is thicker on the bottom of the trench and on part of the side walls of the trench continuous to the bottom than on the other parts.

Growing community of inventors

Tokyo, Japan

Akihiko Osawa