Sharp Kabushiki Kaisha Corporation

Sharp Corporation

Yoshihisa Fujii

Katsuki Furukawa

Akira Suzuki

Mitsuhiro Shigeta

Kenji Nakanishi

Hajime Saito

Keisuke Miyazaki

Yoshinori Ohitsu

Atsuko Ogura

Akitsugu Hatano

Yoshimitsu Tajima

Atsuko Uemoto

Provided is a semiconductor laser device in which at least an n-type first cladding layer, an active layer and a p-type second cladding layer are formed on or above an n-type semiconductor substrate. An n-type current block layer having a stripe-shaped groove-like removed portion is formed on the second cladding layer and at least a p-type third cladding layer is formed on the current block layer including the stripe-shaped removed portion. The second cladding layer has a p-type C impurity concentration of 3&#xd7;10cmto 2&#xd7;10cm.

Semiconductor laser device and fabricating method thereof

An object of the present invention is to stably manufacture a semiconductor laser element having a plurality of wavelengths without split of a wafer in a wafering step while preventing a tracking error due to the returning light of three beams in one semiconductor laser. The present invention provides a semiconductor laser element, which comprises a plurality of emitting regions formed on one substrate, each region having different wavelength, wherein at least one side portion of at least one emitting region is opposed to a part of the substrate.

Semiconductor laser element, method for manufacturing the same, and optical pickup using the same

Provided is a semiconductor laser device in which at least an n-type first cladding layer, an active layer and a p-type second cladding layer are formed on or above an n-type semiconductor substrate. An n-type current block layer having a stripe-shaped groove-like removed portion is formed on the second cladding layer and at least a p-type third cladding layer is formed on the current block layer including the stripe-shaped removed portion. The second cladding layer has a p-type C impurity concentration of 3&times;10 cm to 2&times;10 cm .

A method for producing a semiconductor laser device includes the steps of: forming a reflection protective film on a light-emitting facet of a semiconductor laser device; and removing an unwanted reflection protective film formed on a portion other than the light-emitting facet by an etching technique. Furthermore, an apparatus for producing a semiconductor laser device, includes: a formation section forming a reflection protective film on a light-emitting facet of a semiconductor laser device; an etching section removing an unwanted reflection protective film formed on a portion other than the light-emitting facet by an etching technique; a device inverting section turning the semiconductor laser device upside down; and a device transferring section transferring the semiconductor laser device among the formation section, the etching section, and the device inverting section in a predetermined order.

Method and apparatus for producing semiconductor laser device

Method for producing semiconductor laser device

A light emitting diode is disclosed which comprises at least one heterojunction composed of silicon carbide (SIC) and semiconductor materials selected from the group consisting of gallium nitride (GAN), aluminum nitride (AlN), and aluminum gallium nitride (Ga.sub.x Al.sub.1-x N, 0&lt;x&lt;1).

Light emitting diode

A light emitting diode of silicon carbide having a p-n junction comprising an n-type layer doped with donor impurities, a first p-type layer doped with acceptor impurities, and a second p-type layer doped with acceptor impurities and donor impurities. The first p-type layer has a thickness less than the diffusion length of electrons having flowed from the n-type layer. In this way, the first p-type layer effects light emission related to the acceptor impurities which recombine with the electrons having flowed from the n-type layer, and the second p-type layer effects light emission by donor-acceptor pairs which recombine with the electrons having flowed from the n-type layer.

A silicon carbide semiconductor device is provided which includes at least one heterojunction composed of two different polytypes of silicon carbide. The two polytypes of silicon carbide in the heterojunction include a .beta.-type silicon carbide layer having an .alpha.-type silicon carbide layer disposed thereon.

Silicon carbide semiconductor device

This invention is a multi-layer pn type silicon carbide light emitting diode. A first n-type silicon carbide layer is deposited on an n-type substrate. The first n-type silicon carbide layer has an electron concentration larger than 1.times.10.sup.15 cm.sup.-3 and smaller than the electron concentration of the substrate and has a thickness of between 0.1 to 20 .mu.m. A second n-type silicon carbide layer is disposed over the first n-type layer. A first p-type silicon carbide layer is disposed on the second n-type layer to form a PN junction layer.

Multi-layer silicon carbide light emitting diode having a PN junction

A method for the growth of silicon carbide single crystals is disclosed which includes the step of growing silicon carbide single crystals on a silicon single-crystal substrate. The silicon single-crystal substrate has growth areas with a crystal orientation inclined by an angle .theta. from the [100] direction toward at least one of the [011] and [011] directions and with a lateral dimension d taken along the direction of such inclination toward the [011] or [011] direction. The angle .theta. is set to be in the range of zero to tan.sup.-1 (.sqroot.2/8) degrees (with the proviso that the angle .theta. is not equal to tan.sup.-1 (.sqroot.2/2) degrees). The lateral dimension d is set to be in the range of 0.1 to 100 .mu.m. In this method, the silicon carbide single crystals are grown to a thickness t approximately equal to or greater than (.sqroot.2+tan.theta.)d/.vertline.1-.sqroot.2tan.theta..vertline., so that these silicon carbide single crystals are substantially free of defects such as stacking faults.

Method for the growth of silicon carbide single crystals

There are provided silicon carbide light emitting diodes having a p-n junction which is constituted by a p-type silicon carbide single-crystal layer and an n-type silicon carbide single-crystal layer formed thereon. In cases where light emission caused by recombination of free excitons is substantially utilized, at least a part of the n-type silicon carbide layer adjacent to the interface of the p-n junction is doped with a donor impurity at a concentration of 5.times.10.sup.16 cm.sup.-3 or lower. In cases where light emission caused by acceptor-associated recombination is substantially utilized, the p-type silicon carbide layer is doped with an acceptor impurity and at least a part of the n-type silicon carbide layer adjacent to the interface of the p-n junction is doped with a donor impurity at a concentration of 1.times.10.sup.18 cm.sup.-3 or higher. Also provided are a method for producing such silicon carbide light emitting diodes and a method for producting another silicon carbide light emitting diode.

Silicon carbide light emitting diode and a method for the same

There is provided a method for the production of a silicon carbide single crystal, which includes the steps of: providing a silicon single-crystal substrate having a growth plane with a crystal orientation inclined from the [100] direction toward an off-direction, wherein the crystal orientation is defined by a deviation angle .theta. of 5 to 40 degrees, as measured from the [011] direction toward the [011] direction, and a tilt angle .phi. of 1 to 7 degrees, as measured from the [100] direction toward the off-direction; and growing a silicon carbide single crystal on the substrate.

Method for the production of SiC single crystals by using a specific

A silicon carbide field-effect transistor is disclosed which includes an MOS structure composed successively of a silicon carbide layer, a gate insulator film, and a gate electrode. The field-effect transistor has source and drain regions formed in the silicon carbide layer, between which the MOS structure is disposed, wherein at least one of the source and drain regions is formed by the use of a Schottky contact on the silicon carbide layer.

Silicon carbide MOS type field-effect transistor with at least one of

A silicon carbide semiconductor device is disclosed which includes a semiconductor substrate and a silicon carbide single-crystal layer formed above the substrate, the silicon carbide single-crystal layer having a device active region. The silicon carbide semiconductor device further includes an aluminum nitride single-crystal layer which is disposed between the silicon carbide single-crystal layer and the substrate. The aluminum nitride single-crystal layer functions as an electrically insulating layer by which the silicon carbide signale-crystal layer is isolated electrically from the substrate.

A silicon carbide field-effect transistor is provided which includes a semiconductor substrate, a channel formation layer of silicon carbide formed above the substrate, source and drain regions provided in contact with the channel formation layer, a gate insulator disposed between the source and drain regions, and a gate electrode formed on the gate insulator, wherein a first contact between the channel formation layer and the drain region exhibits different electric characteristics from those of a second contact between the channel formation layer and the source region. Also provided is a method for producing such a silicon carbide field-effect transistor.

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Nara, Japan

Yoshihisa Fujii