Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki K.k.

Natsuro Tsubouchi

Masahiko Denda

Masafumi Kimata

Shinichi Sato

Hiroshi Harada

Shiro Hine

Mitsushige Kondou

Toshiaki Suhara

Keizo Kono

Hiroshi Nishihara

Wataru Wakamiya

Masao Nagatomo

Akira Nishimoto

Haruhiko Abe

Shigeji Kinoshita

Junichi Mitsuhashi

Yoshikazu Ohbayashi

Kirokazu Moyoshi

Hirokazu Miyoshi

An optical IC-type head assembly for recording and for reading information on an optical disc, comprising a substrate, a light guiding layer comprising a dielectric thin film formed monolithically on the substrate, a laser oscillator for injecting the laser beam into the light guiding layer, a grating coupler for converging the laser beam on the optical disc, and a photo detector for receiving the beam reflected by the optical disc and coming out of the grating coupler. In one embodiment the substrate is made of material having cleavability. One side surface of the light guiding layer receiving the laser beam is a break surface formed by cleaving the substrate along the cleavage plane. The photo detector is disposed at the break surface of the light guiding layer. The substrate is preferably made of single crystal material. In another embodiment, a beam splitter is disposed between the laser oscillator and the grating coupler for splitting the reflected beam coming out of the grating coupler into two symmetrical beams. Each split beam forms an acute angle with respect to the optical axis of the reflected beam. The acute angle is preferably less than 30 degrees. The beam splitter may converge each of the split beams at a photo detecting element disposed between the laser oscillator and the grating coupler.

Method of producing optical head assembly

A semiconductor memory device such as a MOS dynamic RAM comprises transistor portions (2, 3 and 5) for writing and reading a signal and capacitor portions (1, 2, 6 and 9) by pn junction for storing a signal. The capacitor portions have preferably as large a capacitance as possible. For this purpose, a capacitor hole (7) is formed in a p type semiconductor substrate (6) and an n type semiconductor region (9) is provided along the capacitor hole (7) so that the pn junction area therebetween is increased and the capacitance is made large.

Process for manufacture of a semiconductor memory device

A charge-coupled device comprises a p type silicon substrate (130), a plurality of n type impurity regions (121) of a high impurity concentration, a plurality of n type impurity regions (140) of a low impurity concentration, a silicon oxide film (150) for defining a channel region (10), a gate oxide film (110), a plurality of gate electrodes (21, 31, 41, 51, 22, 32, 42 and 52) and clock bus lines (70, 80, 90 and 100) for applying a clock signal to the respective gate electrodes. The n type impurity regions (121) and (140) are formed alternately in the channel region (10) along a direction perpendicular to the charge transfer direction, whereby the potential in the channel region (10) changes in the above described perpendicular direction. The change of the potential causes a strong electric field in the channel region (10) in the above described perpendicular direction, which serves to prevent carriers from freezing to an impurity level at a low temperature. Thus, the transfer efficiency of carriers is improved.

Charge-coupled device having channel region with alternately changing

Optical head assembly with efficient light source coupling surface and

Semiconductor memory device

A device for detecting light having an improved sensitivity and a method for producing the device. N.sup.+ source and drain regions are formed on a P-type silicon substrate. The substrate is then covered with an oxidation resistant layer of SiO.sub.2. A layer of Pt-Si is then deposited between the source and drain regions and a P-type polysilicon layer is deposited on the Pt-Si layer. The device is then annealed to form a Schottky junction between the polysilicon layer and the Pt-Si layer following which a gate electrode is formed on the polysilicon layer.

Method for producing a Schottky barrier light detecting device

An n-channel MOS dynamic memory cell includes a semiconductor substrate having a p.sup.+ internal region and a p.sup.- surface region disposed on the surface of the internal region except for an n.sup.+ region serving as a bit line, a capacitor electrode disposed above the surface region, and a transfer gate disposed between the capacitor electrode and the n.sup.+ region above the surface region. The surface region except for the n.sup.+ region and a portion of the internal region disposed below the transfer gate are higher in resistivity than at least one of a portion of the internal region disposed below the capacitor electrode and another portion of the internal region disposed below the n.sup.+ region.

Process for manufacturing a semiconductor memory device

A device for detecting infrared rays and a method for manufacturing the same having an improved sensitivity in the infrared range. A first region of a second conductivity type is formed on a substrate of a first conductivity type by diffusion or ion-implantation. Second and third regions of the same conductivity type as the substrate are formed in the first region and the substrate by diffusion or ion-implantation. A metal such as platinum, gold or palladium is evaporated onto an exposed part of the first region by sputtering. The metal layer thus deposited is annealed to form a Schottky contact.

Device for detecting infrared rays

MOSFET Light detecting device having a Schottky junction

A multilayer interconnection is prepared by forming a stable insulating film on a nitride film which is formed on a first interconnection metal layer, and then, a second interconnection metal layer is formed on the insulating film. The insulating film can be made of aluminum oxide, an oxynitride or the other metal oxide. A silicon rich layer can be used for this purpose.

Process for preparing multilayer interconnection

A thin film of a metal which is capable of oxidation and sublimation is formed on a major surface of a semiconductor substrate, and a portion of a major surface of the thin metallic film is irradiated with an oxygen ion beam to convert a portion of the thin metallic film to an oxide, and subsequently the thin metallic film is heat treated to remove the oxide by sublimation, whereby electrodes or wiring for a semiconductor integrated circuit are formed by the remaining thin metallic film.

Method of forming patterned refractory metal films by selective oxygen

An oxidizing tube encircled by an electric heater is disposed within a pressure envelope. A high pressure inert gas is supplied to the envelope and tube while hydrogen and oxygen are supplied to the tube while being kept at an elevated temperature to react with each other to form steam. The steam oxidizes the surfaces of silicon wafers placed in the tube to form silicon dioxide films on them. Alternatively a water evaporator may be disposed within the pressure envelope to directly supply steam to the tube with the high pressure gas aiding the supply of the steam.

Growing community of inventors

Itami, Japan

Natsuro Tsubouchi