Matsushita Electric Industrial Co., Ltd.

Yoichi Sasai

Satoshi Kamiyama

Takashi Nishikawa

Minoru Kubo

Shigeo Yoshii

Kazuhisa Yamamoto

Kiminori Mizuuchi

Tohru Saitoh

Kiyoshi Ohnaka

Ryoko Miyanaga

Nobuyuki Uemura

Jun Shibata

Tetsuo Taniuchi

Toshiya Yokogawa

Makoto Kitabatake

Takeshi Uenoyama

Yuji Judai

Masato Ishino

Ichiro Nakao

Atsushi Noma

Keisaku Nakao

Kazuhiro Ohkawa

Hiraaki Tsujii

Shigeru Ohmori

An underlying conductive film made of iridium and having a thickness of about 0.1 &mgr;m is formed in a contact hole formed in an insulating film covering a transistor formed in a substrate, except in the top portion of the contact hole. The underlying conductive film covers the sidewall portions of the contact hole and the top surface of the drain region but does not completely fill in the contact hole. A plug made of platinum is filled in the contact hole up to the top portion thereof. Over the contact hole of the insulating film, there is formed a capacitor composed of a lower electrode made of platinum, a capacitor insulating film made of SrBi Ta O , and an upper electrode made of platinum in contact relation with the respective upper ends of the underlying conductive film and the plug.

Method for providing a contact hole formed in an insulating film

As a pretreatment of a substrate, a substrate of Si having the (111) surface orientation as a main surface is soaked in hydrofluoric acid, so as to form a H atomic layer for terminating dangling bonds on the main surface of the substrate. Then, the substrate is placed in a highly evacuated growth chamber in an MBE system, and a Ga molecular beam and a Se molecular beam are supplied onto the H atomic layer on the substrate, so as to grow a buffer layer of GaSe, that is, a van der Waals crystal. Next, with the supply of the Se molecular beam stopped, a N,gas activated by using radio frequency or electron cyclotron resonance is supplied instead as a nitrogen source onto the buffer layer on the substrate, so as to form a semiconductor layer of GaN.

Growth of GaN on Si substrate using GaSe buffer layer

The light-emitting diode device of the present invention includes an active layer, a p-type contact layer, a Schottky electrode and an ohmic electrode. The active layer is formed over an n-type semiconductor substrate. The contact layer is formed over the active layer. The Schottky electrode is selectively formed on the contact layer and makes Schottky contact with the contact layer. The ohmic electrode is formed to surround the Schottky electrode on the contact layer and to be electrically connected to the Schottky electrode and transmits the light emitted from the active layer.

Light-emitting diode device

On a substrate of n-type GaAs, an n-type cladding layer of n-type Zn.sub.0.9 Mg.sub.0.1 S.sub.0.13 Se.sub.0.87, an n-type light guiding layer of n-type ZnS.sub.0.06 Se.sub.0.94, an active layer of ZnCdSe and a p-type light guiding layer of p-type ZnS.sub.0.06 Se.sub.0.94 are successively formed. On the p-type light guiding layer, a p-type contact structure is formed. The p-type contact structure includes a first layer of p-type ZnS.sub.0.31 Se.sub.0.54 Te.sub.0.15, a second layer of ZnS.sub.0.47 Se.sub.0.28 Te.sub.0.25, a third layer of p-type ZnS.sub.0.65 Te.sub.0.35, a fourth layer of p-type ZnS.sub.0.5 Te.sub.0.5 and a fifth layer of p-type ZnTe.

Low barrier ohmic contact for semiconductor light emitting device

The present invention relates to a bar code reading apparatus that is useful for recognizing by human eyes whether a light beam is being projected onto a bar code symbol. The bar code reading apparatus contains a first and second light source to radiate a first ray and a second visible ray, respectively. The second visible ray has higher visibility than first light beam for human eyes. As a result, an operator can easily recognize whether the light beams are projected onto a bar code symbol. Another bar code reading apparatus contains first and second photo detectors for receiving a first and a second reflected beam, respectively. With this arrangement two different bar code symbols can be simultaneously read by the bar code reading apparatus.

Bar code reading apparatus

In a II-VI group semiconductor laser, on an n type GaAs substrate, an n type ZnSe layer, a multiquantum well layer of a ZnCdSe well layer and a ZnSe barrier layer, and a p type ZnSe layer are deposited in this order. A polycrystalline ZnO layer is provided on both sides of the p type ZnSe layer for constricting current. Multifilm reflecting mirrors, respectively constituted with a polycrystalline SiO.sub.2 layer and a polycrystalline TiO.sub.2 layer, for obtaining laser oscillation are provided on the p type ZnSe layer as well as on a surface of the n type ZnSe layer exposed by etching the GaAs substrate. Furthermore, a p type AuPd electrode and an n type AuGeNi electrode are respectively provided. Alternatively, on an n type GaAs substrate, an n type ZnSe epitaxial layer, an n type ZnMgSSe cladding layer, an n type ZnSSe optical waveguide layer, a ZnCdSe active layer, a p type ZnSSe optical waveguide layer, a p type ZnMgSSe cladding layer, a p type ZnTe contact layer and a polycrystalline ZnO burying layer are respectively formed. Furthermore, a p type AuPd electrode and an n type In electrode are respectively provided.

Semiconductor light emitting device and method for fabricating the same

According to one aspect of the invention, a crystal-growing method for forming a II-VI single crystalline semiconductor expressed by Zn.sub.1-x Cd.sub.x Se (where 0&lt;x&lt;0.35) is provided. The crystal-growing method includes a step of epitaxially growing the II-VI single crystalline semiconductor on a substrate by: supplying a II element Zn onto the substrate by using a molecular beam from a ZnSe compound source and a molecular beam from a Zn elemental source; supplying a II element Cd onto the substrate by using a molecular beam from a CdSe compound source; and supplying a VI element Se onto the substrate by using a molecular beam from a ZnSe compound source.

Semiconductor light-emitting device and production method thereof, and

A semiconductor laser of this invention includes: a semiconductor substrate; a first cladding layer made of first conductivity type ZnMgSSe, which is held by the semiconductor substrate and lattice-matches with the semiconductor substrate; a stripe-shaped second cladding layer made of second conductivity type ZnMgSSe lattice-matching with the semiconductor substrate; a light-emitting layer including a first and a second light guiding layers made of Zn.sub.1-x Mg.sub.x S.sub.1-y Se.sub.y (0.ltoreq.x&lt;1, 0.ltoreq.y&lt;1) and a quantum well layer made of Zn.sub.1-z Cd.sub.z Se (0.ltoreq.z&lt;1) which is interposed between the first and the second light guiding layers, the light-emitting layer being interposed between the first and the second cladding layers; and a burying layer which is made of ZnMgSSe lattice-matching with the semiconductor substrate and formed on sides of the second cladding layer.

Semiconductor laser

A wavelength conversion device exhibiting an excellent wavelength conversion efficiency is provided by forming it in such a manner that an LiTaO.sub.3 substrate is subjected to a proton exchange treatment to form a proton-exchange layer before the proton-exchange layer is subjected to heat treatment to form a domain-inverted structure. Heat treatment is performed at a high temperature rising speed to prevent the thermal diffusion of the proton-exchange layer so that the expansion of the domain-inverted structure to be formed in the proton-exchange layer is restrained. As a result, a higher harmonic wave wavelength conversion device can be provided.

Wavelength conversion device

Method of manufacturing wavelength conversion device

A laser source with small output fluctuations due to variations in ambient temperature. The frequency doubler, which has an optical waveguide formed on the substrate of its nonlinear optical crystal, and the laser generator are fixed on the same optical axis within the lens barrel. Moreover, the material used for the lens barrel has a thermal expansion coefficient which is substantially similar to that of the nonlinear optical crystal.

Laser source

A semiconductor device includes a semiconductor substrate having a plurality of mesa stripes whose widths are different from each other. Quantum well layers are formed on the mesa stripes respectively and have different band gap energies. The quantum well layers include ultra-thin epitaxial layers respectively. Semiconductor elements are formed on the mesa stripes respectively and include the quantum well layers respectively. Thicknesses of the ultra-thin layers are preferably equal to or less than 500 angstroms.

Semiconductor device

An optoelectronic integrated circuit includes an N.sup.+ type cladding layer, an N type cladding layer, an active layer smaller in band gap than the N type cladding layer and a P type waveguide greater in band gap than the active layer sequentially formed on a semi-insulating substrate, a P type cladding layer partially formed on the surface of the P type waveguide, a laser composed of these N.sup.+ type and N type cladding layers, active layer, waveguide and P type cladding layer, and an N type emitted layer wider in band gap than the P type waveguide formed partially on the surface of the P type waveguide, thereby composing a heterojunction bipolar transistor using the N type cladding layer as the collector and the P type waveguide as the base.

Optoelectronic integrated circuit

A semiconductor laser in which an InGaAsP active layer serving as light emitting layer and formed in the shape of a stripe on the surface of a flat InP first clad layer, and an InP second clad layer that is wider than the InGaAsP active layer and formed on the InGaAsP active layer are buried in an InP burying layer. The stripe direction is the &lt;011&gt; direction, an etched mirror is formed in the vicinity of the end of the active layer, and an opto-electronic integrated circuit is formed by integrating the electric device and photo detecting device on the same substrate. The substrate is a semi-insulating substrate, and the electric device and photo detecting device are formed on the InGaAsp or InGaAs layer formed on the InP burying layer by crystal growth.

Semiconductor light emitting device

Disclosed is a liquid phase epitaxial growth method using a slider having a recess which receives a semiconductor substrate, and a growth boat having a solution holder which holds plural kinds of solutions for use in epitaxial growth, in which method, epitaxial growth of a layer having thickness of less than 500 .ANG. is carried out under the condition that the slider is sliding in one direction, i.e., without stopping the sliding movement of the slider. Thereby, the thickness of the growth layer is controlled by controlling the time when the substrate contacts the solution, or by the sliding speed of the slider.

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Hirakata, Japan

Yoichi Sasai