Denso Corporation

Nippondenso Co., Ltd.

Nippon Soken, Inc.

Kabushiki Kaisha Toyota Chuo Kenkyusho

Masaki Matsui

Shinichi Hoshi

Hisayoshi Ohshima

Shoichi Yamauchi

Kunihiro Onoda

Yoshinori Tsuchiya

Hiroaki Himi

Seiji Fujino

Tetsuo Narita

Masatake Nagaya

Kenji Itoh

Kenji Ito

Tetsu Kachi

Jun Sakakibara

Takeshi Enya

Kazuyoshi Tomita

Yasushi Higuchi

Mitsutaka Katada

Kazuhiro Tsuruta

Akitoshi Yamanaka

Akiyoshi Asai

Kazuhiro Oyama

Seigo Oosawa

Takanari Sasaya

Hiroyuki Tarumi

Youngshin Eum

Nobuyuki Otake

Toshifumi Izumi

Tadao Ooka

Tosiaki Nisizawa

Akinari Fukaya

A semiconductor device includes a GaN device provided with: a substrate made of a semi-insulating material or a semiconductor; a channel-forming layer including a GaN layer arranged on the substrate; a gate structure in which a gate-insulating film in contact with the GaN layer is arranged on the channel-forming layer, the gate structure having a gate electrode arranged across the gate-insulating film; and a source electrode and a drain electrode that are arranged on the channel-forming layer and on opposite sides interposing the gate structure. The donor element concentration at the interface between the gate-insulating film and the GaN layer and at the lattice position on the GaN layer side with respect to the interface is set to be less than or equal to 5.0&#xd7;10cm.

Semiconductor device and method for producing same

A semiconductor device includes a lateral switching device having: a substrate; a channel forming layer that has a heterojunction structure made of a GaN layer and an AlGaN layer and is formed with a recessed portion, on the substrate; a gate structure part that includes a gate insulating film and a gate electrode formed in the recessed portion; and a source electrode and a drain electrode on opposite sides of the gate structure part on the channel forming layer. The AlGaN layer includes a first AlGaN layer that has an Al mixed crystal ratio determining a two dimensional electron gas density, and a second AlGaN layer that has an Al mixed crystal ratio smaller than that of the first AlGaN layer to induce negative fixed charge, and is disposed in contact with the gate structure part and spaced from the source electrode and the drain electrode.

Semiconductor device

In a semiconductor device, a gate insulating film is provided with a multi-layer structure including a first insulating film and a second insulating film. The first insulating film is formed of an insulating film containing an element having an oxygen binding force larger than that of an element contained in the second insulating film, and the total charge amount is increased. Specifically, by performing oxygen anneal, it is possible to perform the step of supplying oxygen into an aluminum oxide film and increase the total charge amount. This allows a negative fixed charge density in the gate insulating film in the vicinity of an interface with a GaN layer to be set to a value of not less than 2.5&#xd7;10cmand allows a normally-off element to be reliably provided.

Semiconductor device and method for manufacturing the same

A step-flow growth of a group-III nitride single crystal on a silicon single crystal substrate is promoted. A layer of oxide oriented to a &#x3c;111&#x3e; axis of silicon single crystal is formed on a surface of a silicon single crystal substrate, and group-III nitride single crystal is crystallized on a surface of the layer of oxide. Thereupon, a &#x3c;0001&#x3e; axis of the group-III nitride single crystal undergoing crystal growth is oriented to a c-axis of the oxide. When the silicon single crystal substrate is provided with a miscut angle, step-flow growth of the group-III nitride single crystal occurs. By deoxidizing a silicon oxide layer formed at an interface of the silicon single crystal and the oxide, orientation of the oxide is improved.

Layered substrate with a miscut angle comprising a silicon single crystal substrate and a group-III nitride single crystal layer

A manufacturing method of a semiconductor device including arranging a compound semiconductor above a stage of a chamber, supplying an etching gas into the chamber, and generating a plasma in the chamber is provided. The compound semiconductor includes a group-III element nitride as a main component. A surface of the compound semiconductor is processed by a dry etching. Light is irradiated into the chamber during the generating of the plasma. A dry etching apparatus including a chamber including a stage, on which a compound semiconductor is mounted, and a light source irradiating light into the chamber is provided. The chamber is supplied with an etching gas. A plasma is generated in the chamber. A surface of the compound semiconductor is an object of a dry etching.

Manufacturing method of semiconductor device and dry etching apparatus for the same

In a mechanochemical polishing apparatus, a SiC wafer is held on a wafer holding table. The surface of the wafer to be polished is pressed against a polishing cloth applied to a polishing platen with a predetermined processing pressure. The wafer holding table and polishing platen are then rotated to perform polishing with chemical liquid dropped on the polishing cloth. The chemical liquid includes chromium (III) oxide as abrasive grains and hydrogen peroxide water (oxidizing agent) for improving polishing efficiency.

Method and apparatus for mechanochemical polishing

Before a semiconductor substrate and a base substrate is directly bonded to one another, in a protective film removing step, a contamination protective film formed on the semiconductor substrate to protect it from contamination during an ion implanting step is removed. Consequently, even when flatness of the contamination protective film is degraded during the ion implanting step or even when contaminants remain in a segregated state in the vicinity of the surface of the contamination protective film, the state of the bonding between the semiconductor substrate and the base substrate after the bonding step can be made uniform over the entire area of the bonding. As a result, a high-quality semiconductor substrate can be manufactured at low cost.

Semiconductor substrate and method of manufacturing the same

The invention provides a number of semiconductor substrate manufacturing methods with which, in manufacturing a semiconductor substrate having a semiconductor layer in an insulated state on a supporting substrate, it is possible to obtain a thick semiconductor layer with a simple process and cheaply while reducing impurity contamination of the semiconductor layer to a minimum. One of these methods includes a defective layer forming step of carrying out ion implantation to a predetermined depth from the surface of a base substrate to partition off a monocrystalline thin film layer at the surface of the base substrate by a defective layer formed by implanted ions, a semiconductor film forming step of forming a monocrystalline semiconductor film of a predetermined thickness on the monocrystalline thin film layer, a laminating step of laminating the base substrate by the surface of the monocrystalline semiconductor film to the supporting substrate, and a detaching step of detaching the base substrate laminated to the supporting substrate at the defective layer.

Semiconductor substrate manufacturing method

Methods for manufacturing semiconductor substrates in which a semiconductor layer for forming semiconductor device therein is formed on a supporting substrate with an insulating film interposed between, with which in forming the semiconductor layer on a substrate on which a buried pattern structure has been formed it is possible to greatly increase the film thickness uniformity of the semiconductor layer and the film thickness controllability, particularly when the semiconductor layer is being formed as an extremely thin film. As a result, it is possible to achieve improved quality and characteristics of the semiconductor substrates and make possible the deployment of such semiconductor substrates to various uses.

Method for manufacturing a semiconductor substrate

In a method for producing a semiconductor substrate completed through a bonding process for joining a semiconductor wafer to a support substrate by performing heat treatment thereto in a state in which the semiconductor wafer is closely joined to the support substrate, the method according to the present invention includes the following steps, i.e., a depositing process for depositing a poly-crystal semiconductor which covers all areas of a surface to be bonded on the surface of the semiconductor wafer; a heat treatment process for performing the heat treatment to the semiconductor wafer provided after the depositing process, during a predetermined time under a temperature equal to or higher than the heat treatment temperature at the bonding process; and a polishing process for flattening the surface of the poly-crystal semiconductor provided after the heat treatment process. After the above processes were performed in order, the bonding process is performed after the polishing process.

Method for producing a semiconductor substrate

In a dielectric isolation substrate, an end point of a polishing process for selective polishing for forming an SOI layer is detected with a high precision. When polishing a wafer with a polishing pad, the temperature of a region of the polishing pad having polished the wafer at a position immediately thereafter is detected by a temperature sensor and the selective polishing process is ended by discriminating that the rate of variation in the detected temperature has changed from a positive to a negative state and then to a fixed saturated state.

Polishing method for SOI

Disclosed is a method of manufacturing a semiconductor substrate by bonding two silicon crystalline wafers, and particularly, to a method of manufacturing a semiconductor substrate capable of reduced electrical resistance at the bonding interface. In the disclosed method, the silicon wafers to be bonded have at least one surface mirror-polished. Then they are washed, thus forming a natural oxide film on the surface. Then they are soaked in a concentrated HF solution for enough time to remove the oxide film formed on the surface. After that, the silicon wafers are soaked in ultra pure water to replace the fluorine atoms terminated on the surface thereof by OH groups, followed by drying. The silicon wafers thus treated are closely contacted with each other in such a manner that the mirror-polished surfaces are opposed to each other. The silicon wafers are thus bonded to each other by the hydrogen bonding forces due to the OH groups, and then heat treated for reinforcing the bonding.

Method of manufacturing semiconductor substrate

A dielectric buried layer is formed inside substrates which are directly bonded together. Firstly, a groove or a recess, or both are formed on the principal bonding plane of one of at least two kinds of semiconductor substrates to be bonded together. Once the semiconductor substrates are bonded together, the groove and recess form a space, which is filled with dielectric. Before forming the dielectric buried layer, the invention carries out a process of removing potential damage from corners of the groove and/or recess.

Growing community of inventors

Nagoya, Japan

Masaki Matsui