Sharp Kabushiki Kaisha Corporation

Naoki Fukunaga

Masaru Kubo

Takahiro Takimoto

Isamu Ohkubo

Kazuhiro Natsuaki

Toshimitsu Kasamatsu

Mutsumi Oka

Hirohisa Warita

Hiroyuki Shoji

Mitsuru Mariyama

Katsumi Inaba

Yasuhiro Maruyama

Masakazu Ikeda

Hideo Wada

Toshihiko Fukushima

Shigeki Hayashida

Motohiko Yamamoto

Makoto Hosokawa

An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

LED drive circuit, LED illumination component, LED illumination device, and LED illumination system

A trimmer resistance component of the present invention has a trimmer resistor constructed of a p-type diffusion layer formed on the surface of an n-type epitaxial layer. A first electrode is connected to a portion located on one end side of this trimmer resistor, while a first connection portion, a second connection portion and a third connection portion of the second electrode are connected to portions located on the other end side. By cutting a portion of the first connection portion and a portion of the second connection portion by laser trimming, a resistance value between the first electrode and the second electrode can be trimmed without changing a parasitic capacitance between the trimmer resistor and the n-type epitaxial layer.

Trimmer impedance component, semiconductor device and trimming method

A photodiode includes a first conductivity type semiconductor substrate or a first conductivity type semiconductor layer; a second conductivity type semiconductor layer provided on the first conductivity type semiconductor substrate or the first conductivity type semiconductor layer; an anti-reflection film provided on a surface of a portion of the second conductivity type semiconductor layer which is in a light receiving area; a first conductive layer provided in an area in the vicinity of the light receiving area; and a passivation layer provided on the first conductive layer. Light incident on the photodiode is detected by a junction of the one of the first conductivity type semiconductor substrate and the first conductivity type semiconductor layer, and the second conductivity type semiconductor layer. The area in the vicinity of the light receiving area includes a window area having an opening in the passivation layer for partially exposing the first conductive layer.

Photodiode device including window defined in passivation layer for removing electrostatic charge

A corrosion-resistant conductive layer (TiW layer) formed of a corrosion-resistant material is formed to extend from a bonding pad portion to an interconnection portion of a light receiving element. A semiconductor laser device according to the present invention includes the light receiving element.

Light receiving element and semiconductor laser device

A circuit-incorporating light receiving device includes an integrated circuit and a photodiode. The integrated circuit and the photodiode are provided on a single semiconductor substrate. The integrated circuit includes a transistor having a polycrystalline silicon as an emitter diffusion source and an electrode. Elements included in the integrated circuit are isolated from each other using local oxidization.

Circuit-incorporating light receiving device and method of fabricating the same

A photodiode converts light incident thereon into an electric signal by a junction between an N-type epitaxial layer and a P-type epitaxial layer with a sufficiently small junction capacitance. The photodiode is surrounded by a P -type buried isolating diffused layer and a P-type isolating diffused layer, and thus is electrically separated from a signal processing circuit including a MOS transistor.

Light receiving device with built-in circuit

A photosensitive device includes a semiconductor substrate and a first semiconductor layer, both of a first conductivity type, with the semiconductor layer being formed on the semiconductor substrate and having a lower impurity concentration than that of the semiconductor substrate. A second semiconductor layer, of a second conductivity type, is formed on the first semiconductor layer and at least one diffusion layer of the first conductivity type is formed from the surface of the second semiconductor layer so as to reach the surface of the first semiconductor layer. The diffusion layer subdivides the second semiconductor layer into a plurality of semiconductor regions At least one photodiode portion for converting signal light into an electrical signal is formed at a junction between at least one of the plurality of semiconductor regions and the first semiconductor layer. A depletion layer which is formed in the first semiconductor layer when a reverse bias voltage is applied to the at least one photodiode portion has a field intensity of about 0.3 V/&mgr;m or more.

Light sensitive element and light sensitive element having internal circuitry

A circuit-integrated light-receiving device of the present invention includes: a semiconductor substrate of a first conductivity type; a first semiconductor crystal growth layer of the first conductivity type provided on a surface of the semiconductor substrate, wherein the first semiconductor crystal growth layer includes a first portion whose impurity concentration gradually decreases in a direction away from the surface of the semiconductor substrate and a second portion located in a first region above the first portion whose impurity concentration distribution is uniform in a depth direction; a buried diffusion layer of the first conductivity type located in a second region which is above the first portion of the first semiconductor crystal growth layer and does not overlap the first region; a second semiconductor crystal growth layer of a second conductivity type which is provided across a surface of the first semiconductor crystal growth layer and a surface of the buried diffusion layer; and a separation diffusion region having the first conductivity type for dividing the second semiconductor crystal growth layer into a light-receiving device section and a signal processing circuit section. The first region is located in the light-receiving device section. In the signal processing circuit section, the buried diffusion layer is in contact with the first portion of the first semiconductor crystal growth layer.

Circuit-integrated light-receiving device

The circuit-integrating light-receiving element of this invention includes: a semiconductor substrate of a first conductivity type; a first semiconductor layer of a second conductivity type formed over the semiconductor substrate; a first semiconductor layer of the first conductivity type for dividing the first semiconductor layer into semiconductor regions of the second conductivity type; light-detecting sections being constituted by the divided semiconductor regions and underlying regions of the semiconductor substrate, a divided photodiode being composed of the light-detecting sections; a second semiconductor layer of the second conductivity type formed only in the vicinity of the first semiconductor layer of the first conductivity type functioning as a division section of the divided photodiode and within the regions of the semiconductor substrate forming the respective light-detecting sections; and a second semiconductor layer of the first conductivity type formed in a surface region of the first semiconductor layer of the second conductivity type including the division section so as to cover an upper part of the second semiconductor layer of the second conductivity type.

Circuit-integrating light-receiving element

A light-receiving element includes a semiconductor substrate of a first conductivity type; a first semiconductor layer of a second conductivity type which is formed in a predetermined region on a surface of the semiconductor substrate of the first conductivity type; and at least one semiconductor region of the first conductivity type which is formed so as to extend from an upper surface of the first semiconductor layer of the second conductivity type to the surface of the semiconductor substrate of the first conductivity type, thereby dividing the first semiconductor layer of the second conductivity type into a plurality of semiconductor regions of the second conductivity type. In the light-receiving element, a specific resistance of the semiconductor substrate of the first conductivity type is set in a predetermined range such that a condition Xd.gtoreq.Xj is satisfied between a depth Xd of a depletion layer to be formed in the semiconductor substrate of the first conductivity type upon an application of an inverse bias and a diffusion depth Xj of the semiconductor region of the first conductivity type into the semiconductor substrate of the first conductivity type.

Light-receiving element

A divided photodiode includes a semiconductor substrate; a semiconductor layer formed on a surface of the semiconductor substrate; and a plurality of isolating diffusion regions formed in a plurality of regions in the semiconductor layer so as to respectively extend from a surface of the semiconductor layer opposite to the other surface thereof in contact with a surface of the semiconductor substrate and to reach regions under the surface of the semiconductor substrate, thereby dividing the semiconductor layer into at least three semiconductor regions. A first buried diffusion region is further formed under the other isolating diffusion regions except for a particular one located in an isolating section in a combination of a plurality of the semiconductor regions which are adjacent to each other via the isolating section, and a depletion of the semiconductor substrate in a region under the other isolating diffusion region by the application of a reverse bias thereto is suppressed.

Divided photodiode

A light receiving device including a semiconductor substrate of a first conductivity type; a first semiconductor layer of a second conductivity type which is formed on the semiconductor substrate of the first conductivity type; and a semiconductor layer of the first conductivity type which elongates from a surface of the first semiconductor substrate of the second conductivity type to reach a surface of the semiconductor substrate of the first conductivity type, the semiconductor layer splitting the first semiconductor layer of the second conductivity type into a plurality of semiconductor regions of the second conductivity type. The portion of the semiconductor layer of the first conductivity type which overlaps with the semiconductor substrate of the first conductivity type is formed as a semiconductor region of the first conductivity type and has a high-impurity density. The semiconductor regions of the second conductivity type, and semiconductor substrate of the first conductivity type below such regions form a plurality of light detecting photodiode portions for detecting signal light. The device further includes a second semiconductor layer of the second conductivity type being buried in a part of the semiconductor substrate of the first conductivity type which constitutes each of the light detecting photodiode portions.

Growing community of inventors

Soraku-gun, Japan

Naoki Fukunaga