Fuji Electric Co., Ltd.

Masaaki Ogino

Haruo Nakazawa

Kenichi Iguchi

Tsunehiro Nakajima

Hiroki Wakimoto

Masaaki Tachioka

Hideaki Teranishi

Koh Yoshikawa

Hidenao Kuribayashi

Shunsuke Tanaka

Yoshikazu Takahashi

Eiji Mochizuki

Naoto Fujishima

Masayuki Miyazaki

Kiyokazu Nakagawa

Takashi Saito

An impurity-doping apparatus is provided with: a supporting plate which supports a semiconductor substrate; a wall-like block disposed above the supporting plate floating away from the semiconductor substrate, the wall-like block implements a recess inside so as to establish a space for a solution region containing impurity elements, the solution region is localized on an upper surface of the semiconductor substrate, the upper surface being opposite to an bottom surface facing to the supporting plate; and a laser optical system, configured to irradiate a laser beam onto the upper surface of the semiconductor substrate, through the solution region surrounded by the wall-like block, wherein the impurity elements are doped into a part of the semiconductor substrate by irradiation of the laser beam.

Impurity adding apparatus, impurity adding method, and semiconductor element manufacturing method

A MOS gate structure including a p base region, a p epitaxial layer, an nsource region, a pcontact region, an n inversion region, a gate insulating film, and a gate electrode and a front surface electrode are provided on the front surface of an epitaxial substrate obtained by depositing an nepitaxial layer on the front surface of a SiC substrate. A first metal film is provided on the front surface electrode so as to cover 10% or more, preferably, 60% to 90%, of an entire upper surface of the front surface electrode. The SiC-MOSFET is manufactured by forming a rear surface electrode, forming the first metal film on the surface of the front surface electrode, and annealing in a Natmosphere. According to this structure, it is possible to suppress a reduction in gate threshold voltage in a semiconductor device using a SiC semiconductor.

Semiconductor device and semiconductor device manufacturing method

A reverse blocking IGBT is manufactured using a silicon wafer sliced from a single crystal silicon ingot which is manufactured by a floating method using a single crystal silicon ingot manufactured by a Czochralski method as a raw material. A separation layer for ensuring a reverse blocking performance of the reverse blocking IGBT is formed by diffusing impurities implanted into the silicon wafer using a thermal diffusion process. The thermal diffusion process for forming the separation layer is performed in an inert gas atmosphere at a temperature equal to or more than 1290&#xb0; C. and less than the melting point of silicon. In this way, no crystal defect occurs in the silicon wafer and it is possible to prevent the occurrence of a reverse breakdown voltage defect or a forward defect in the reverse blocking IGBT and thus improve the yield of a semiconductor element.

Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device includes providing a semiconductor substrate having a front surface and a back surface; forming a transition metal layer on a surface of the semiconductor substrate; and exposing the semiconductor substrate having the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves, to cause the transition metal layer to generate heat. During exposure of the semiconductor substrate, a portion of the semiconductor substrate contacting the transition metal layer is heated by a transfer of heat from the transition metal layer and, at an interface of the transition metal layer and the semiconductor substrate, an ohmic contact is formed by reaction of the transition metal layer and the semiconductor substrate, such as to form a transition metal silicide when the semiconductor substrate is silicon carbide. The ohmic contact provides a lower contact resistivity and device properties can be prevented from degrading.

Method for forming metal-semiconductor alloy using hydrogen plasma

A semiconductor device includes a semiconductor substrate that is made of a semiconductor material with a wider band gap than silicon, a field effect transistor, including a front surface element structure, provided on a front surface of the substrate, and a drain electrode having surface contact with the substrate so as to form a Schottky junction between the semiconductor substrate and the drain electrode.

Semiconductor device having schottky junction between substrate and drain electrode

A first nickel film is deposited inside a contact hole of an interlayer dielectric formed on an n-type SiC substrate. Irradiation with a first laser is carried out, forming an Ohmic contact with a silicon carbide semiconductor. A second nickel film and a front surface electrode film are deposited on the first nickel film, forming a source electrode. The back surface of the n-type SiC substrate is ground, and a third nickel film is formed on the ground back surface of the n-type SiC substrate. Irradiation with a second laser is carried out, forming an Ohmic contact with the silicon carbide semiconductor. A fourth nickel film and a back surface electrode film are deposited on the third nickel film, forming a drain electrode. By so doing, it is possible to prevent electrical characteristic deterioration of a semiconductor device, and to prevent warping and cracking of a wafer.

Semiconductor device manufacturing method

A method for manufacturing a semiconductor device having a MOS gate structure includes forming a device structure on a semiconductor substrate; forming an interlayer dielectric to cover the device structure; forming a contact hole through the interlayer dielectric; forming a transition metal film (e.g., Ni) on a portion of the semiconductor substrate exposed by the contact hole; (e) forming a metal film (e.g., Ti) on the entire surface of the semiconductor substrate; forming an oxide film in the surface of the metal film; selectively removing the metal film in which the oxide film has been formed, to thereby expose the transition metal film; and (h) exposing, to a hydrogen plasma atmosphere, the semiconductor substrate in which the transition metal film and the oxide film have been exposed, to thereby cause the transition metal film to generate heat and react with the semiconductor substrate and form an ohmic contact there between.

Method for manufacturing a semiconductor device by exposing, to a hydrogen plasma atmosphere, a semiconductor substrate

A method for introducing impurity into a semiconductor substrate includes bringing a solution containing a compound of an impurity element into contact with a primary surface of a semiconductor substrate; and irradiating the primary surface of the semiconductor substrate with a laser beam through the solution to raise a temperature of the primary surface of the semiconductor substrate at a position irradiated by the laser beam so as to dope the impurity element into the semiconductor substrate. The laser beam irradiation is performed such that the raised temperature does not return to room temperature until a prescribed dose of the impurity element is caused to be doped into the semiconductor substrate.

Impurity introducing method, impurity introducing apparatus, and method of manufacturing semiconductor element

A method of manufacturing a semiconductor device includes forming a device structure in a surface of a semiconductor substrate, forming, in a face of the semiconductor substrate, a transition metal layer that contacts the semiconductor substrate, and exposing the semiconductor substrate having the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves to cause the transition metal layer to generate heat. During exposure of the semiconductor substrate to the hydrogen plasma atmosphere, a portion of the semiconductor substrate contacting the transition metal layer is heated by a transfer of the heat from the transition metal layer, and an ohmic contact is formed at an interface of the transition metal layer and the semiconductor substrate by reaction of the transition metal layer and the semiconductor substrate. When the semiconductor substrate is silicon carbide, the ohmic contact is composed of a silicide, such as a transition metal silicide.

Method of manufacturing a semiconductor device

A method of manufacturing a semiconductor device that reduces degradation of device properties includes forming an impurity region in a surface layer of a semiconductor substrate by ion injection; forming a transition metal layer in a surface of the impurity region; and exposing the semiconductor substrate with the transition metal layer formed thereon to a hydrogen plasma atmosphere formed by microwaves. The transition metal layer is heated and the heat is transferred from the transition metal layer to the impurity region to form an ohmic contact at the interface of the transition metal layer and the impurity region by reaction of the transition metal layer and the impurity region, and the impurity region is activated. When the substrate is a silicon carbide substrate, the ohmic contact is composed of a transition metal silicide and the impurity region, which is an ion injection layer, is activated.

A method for manufacturing a silicon semiconductor substrate including a diffusion layer prior to forming a semiconductor device thereon, includes providing a silicon semiconductor substrate which is manufactured by a floating zone method; and performing thermal diffusion at a heat treatment temperature that is equal to or higher than 1290&#xb0; C. and that is lower than a melting temperature of a silicon crystal to form a diffusion layer with a depth of 50 &#x3bc;m or more in the silicon semiconductor substrate, the thermal diffusion including a first heat treatment performed in an atmosphere consisting of oxygen or oxygen and at least one of argon, helium, or neon, followed by a second heat treatment performed in an atmosphere comprised of nitrogen or nitrogen and oxygen to form the diffusion layer. The method suppresses the occurrence of crystal defects, reduces the amount of inert gas used, and reduces manufacturing costs.

Method for manufacturing a silicon semiconductor substrate including a diffusion layer prior to forming a semiconductor device thereon

A method for producing a semiconductor device is disclosed which includes a diffusion step of forming, on a CZ-FZ silicon semiconductor substrate, a deep diffusion layer involving a high-temperature and long-term thermal diffusion process which is performed at a thermal diffusion temperature of 1290&#xb0; C. to a melting temperature of a silicon crystal for 100 hours or more; and a giving step of giving a diffusion source for an interstitial silicon atom to surface layers of two main surfaces of the silicon semiconductor substrate before the high-temperature, long-term thermal diffusion process. The step of giving the diffusion source for the interstitial silicon atom to the surface layers of the two main surfaces of the silicon semiconductor substrate is performed by forming thermally-oxidized films on two main surfaces of the silicon semiconductor substrate or by implanting silicon ions into surface layers of the two main surfaces of the silicon semiconductor substrate.

Method for producing semiconductor device

Some embodiments of the present invention relate to a semiconductor device and a method of manufacturing a semiconductor device capable of preventing the deterioration of electrical characteristics. A p-type collector region is provided on a surface layer of a backside surface of an n-type drift region. A p-type isolation layer for obtaining reverse blocking capability is provided at the end of an element. In addition, a concave portion is provided so as to extend from the backside surface of the n-type drift region to the p-type isolation layer. A p-type region is provided and is electrically connected to the p-type isolation layer. The p-type isolation layer is provided so as to include a cleavage plane having the boundary between the bottom and the side wall of the concave portion as one side.

A method includes forming on a first main surface of a semiconductor wafer of a first conduction type, a gate electrode of a semiconductor element, an edge termination region for forming a breakdown voltage of the semiconductor element, and a first semiconductor region of a second conduction type which surrounds the semiconductor element and the edge termination region. A groove may be formed to reach the first semiconductor region from a second main surface of the semiconductor wafer. The groove is formed so that a portion of the semiconductor wafer, that forms an outer circumferential end of the semiconductor wafer, remains and the groove is further towards a center of the semiconductor wafer than the outer circumferential end. A third semiconductor region of the second conduction type is on a side wall of the groove and electrically connects the first semiconductor region and a second semiconductor region.

Method for manufacturing semiconductor device

A semiconductor device and its method of manufacture. In the method, a front surface element structure is formed on a front surface of a semiconductor wafer, for example an SiC wafer. Then, a supporting substrate is bonded to wafer's front surface through an adhesive. The wafer's rear surface is ground and polished to thin it, with the supporting substrate bonded to the wafer. Next a V groove passing through the SiC wafer and reaching the adhesive is formed in the wafer's rear surface, and the wafer is cut into individual chips. An electrode film is formed on the groove's side wall and the chip's rear surface and a Schottky junction is formed between a drift layer, which is the chip, and the film. Then, the film is annealed. A tape is attached to the wafer's rear surface which has been cut into the chips. Then, the supporting substrate peels off from the wafer.

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Matsumoto, Japan

Masaaki Ogino