Tamura Corporation

Novel Crystal Technology, Inc.

National Institute of Information and Communications Technology, Incorporated

Tdk Corporation

Tokyo University of Agriculture and Technology

Sicoxs Corporation

National University Corporation Tokyo University of Agriculture and Technology

Kohei Sasaki

Masataka Higashiwaki

Minoru Fujita

Jun Hirabayashi

Jun Arima

Daiki Wakimoto

Akinori Koukitu

Yoshinao Kumagai

Hisashi Murakami

Ken Goto

Quang Tu Thieu

Akito Kuramata

Yuki Koishikawa

Man Hoi Wong

Shinya Watanabe

Kuniaki Yagi

Naoki Hatta

Yoshiaki Nakata

Takafumi Kamimura

Nobuo Machida

Keita Konishi

A semiconductor device includes a lead frame including a raised portion on a surface, and a semiconductor element that is face-down mounted on the lead frame and includes a substrate including a GaO-based semiconductor, an epitaxial layer including a GaO-based semiconductor and stacked on the substrate, a first electrode connected to a surface of the substrate on an opposite side to the epitaxial layer, and a second electrode connected to a surface of the epitaxial layer on an opposite side to the substrate and including a field plate portion at an outer peripheral portion. The semiconductor element is fixed onto the raised portion. An outer peripheral portion of the epitaxial layer, which is located on the outer side of the field plate portion, is located directly above a flat portion of the lead frame that is a portion at which the raised portion is not provided.

Semiconductor device

A method for manufacturing a semiconductor film includes placing a semiconductor substrate including a β-GaO-based single crystal in a reaction chamber of an HVPE apparatus. When the semiconductor substrate is placed so that the growth base surface faces upward, an inlet for a dopant-including gas into the space is positioned higher than an inlet for an oxygen-including gas into the space and an inlet for a Ga chloride gas into the space is positioned higher than the inlet for the dopant-including gas into the space. When the semiconductor substrate is placed so that the growth base surface faces downward, the inlet for the dopant-including gas into the space is positioned higher than the inlet for the Ga chloride gas into the space and the inlet for the oxygen-including gas into the space is positioned higher than the inlet for the dopant-including gas into the space.

Method of manufacturing a beta-GaO-based single crystal film by flowing a Ga chloride gas, an oxygen gas, and a dopant gas

Provided is a GaO-based single crystal substrate capable of achieving a high processing yield. A GaO-based single crystal substrate having a crack density of less than 0.05 cracks/cm can be obtained that has as a principal surface thereof a surface rotated 10-150° from the (100) plane, when a rotation direction from the (100) plane to the (001) plane via the (101) plane is defined as positive, having the [010] axis as the rotation axis.

Ga2O3-based single crystal substrate

A field-effect transistor includes an n-type semiconductor layer that includes a GaO-based single crystal and a plurality of trenches opening on one surface, a gate electrode buried in each of the plurality of trenches, a source electrode connected to a mesa-shaped region between adjacent trenches in the n-type semiconductor layer, and a drain electrode directly or indirectly connected to the n-type semiconductor layer on an opposite side to the source electrode.

Field effect transistor

As one embodiment, the present invention provides a method for growing a β-GaO-based single crystal film by using HYPE method. The method includes a step of exposing a GaO-based substrate to a gallium chloride-based gas and an oxygen-including gas, and growing a β-GaO-based single crystal film on a principal surface of the GaO-based substrate at a growth temperature of not lower than 900° C.

Method for growing beta-GaO-based single crystal film, and crystalline layered structure

A Schottky barrier diode includes a semiconductor layer including a GaO-based single crystal, an anode electrode that forms a Schottky junction with the semiconductor layer and is configured so that a portion in contact with the semiconductor layer includes Mo or W, and a cathode electrode. A turn-on voltage thereof is not less than 0.3 V and not more than 0.5 V.

Schottky barrier diode

A Schottky barrier diode includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, and a cathode electrode brought into ohmic contact with the semiconductor substrate. The drift layer has a plurality of trenches formed in a position overlapping the anode electrode in a plan view. Among the plurality of trenches, a trench positioned at the end portion has a selectively increased width. Thus, the curvature radius of the bottom portion of the trench is increased, or an edge part constituted by the bottom portion as viewed in a cross section is divided into two parts. As a result, an electric field to be applied to the bottom portion of the trench positioned at the end portion is mitigated, making dielectric breakdown less likely to occur.

An object of the present invention is to provide a Schottky barrier diode less liable to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode according to this disclosure includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrodebrought into Schottky contact with the drift layer, a cathode electrode brought into ohmic contact with the semiconductor substrate, an insulating layer provided on the drift layer so as to surround the anode electrode in a plan view, and a semiconductor layer provided on a surface of a part of the drift layer that is positioned between the anode electrode and the insulating layer and on the insulating layer. The semiconductor layer has a conductivity type opposite to that of the drift layer.

A GaO-based semiconductor device includes a GaO-based crystal layer including a donor, and an N-doped region formed in at least a part of the GaO-based crystal layer.

GA2O3-based semiconductor device

An object of the present invention is to provide a Schottky barrier diode less liable to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode according to this disclosure includes a semiconductor substrate made of gallium oxide, a drift layer made of gallium oxide and provided on the semiconductor substrate, an anode electrode brought into Schottky contact with the drift layer, and a cathode electrode brought into ohmic contact with the semiconductor substrate. The drift layer has an outer peripheral trench surrounding the anode electrode in a plan view. The surface of the drift layer positioned between the anode electrode and the outer peripheral trench is covered with a semiconductor layer having a conductivity type opposite to that of the drift layer.

An object of the present invention is to provide a Schottky barrier diode less apt to cause dielectric breakdown due to concentration of an electric field. A Schottky barrier diode includes a semiconductor substratemade of gallium oxide, a drift layermade of gallium oxide and provided on the semiconductor substrate, an anode electrodebrought into Schottky contact with the drift layer, and a cathode electrodebrought into ohmic contact with the semiconductor substrate. The drift layerhas an outer peripheral trenchthat surrounds the anode electrodein a plan view, and the outer peripheral trenchis filled with a semiconductor materialhaving a conductivity type opposite to that of the drift layer. An electric field is dispersed by the presence of the thus configured outer peripheral trench. This alleviates electric field concentration on the corner of the anode electrode, making it less apt to cause dielectric breakdown.

A trench MOS Schottky diode includes a first semiconductor layer including a GaO-based single crystal, a second semiconductor layer that is a layer stacked on the first semiconductor layer, includes a GaO-based single crystal, and includes a trench opened on a surface thereof opposite to the first semiconductor layer, an anode electrode formed on the surface of the second semiconductor layer, a cathode electrode formed on a surface of the first semiconductor layer, an insulating film covering the inner surface of the trench of the second semiconductor layer, and a trench electrode that is buried in the trench of the second semiconductor layer so as to be covered with the insulating film and is in contact with the anode electrode. The second semiconductor layer includes an insulating dry-etching-damaged layer with a thickness of not more than 0.8 &#x3bc;m in a region including the inner surface of the trench.

Trench MOS schottky diode and method for producing same

A diode includes an n-type semiconductor layer including an n-type GaO-based single crystal, and a p-type semiconductor layer including a p-type semiconductor in which a volume of an amorphous portion is higher than a volume of a crystalline portion. The n-type semiconductor layer and the p-type semiconductor layer form a pn junction.

Diode

A semiconductor substrate includes a single crystal GaO-based substrate and a polycrystalline substrate that are bonded to each other. A thickness of the single crystal GaO-based substrate is smaller than a thickness of the polycrystalline substrate, and a fracture toughness value of the polycrystalline substrate is higher than a fracture toughness value of the single crystal GaO-based substrate.

Growing community of inventors

Tokyo, Japan

Kohei Sasaki