Mitsubishi Chemical Corporation

Mitsubishi Kasei Corporation

Agency of Industrial Science and Technology

Mitsubishi Monsanto Chemical Co., Ltd.

Hideki Gotoh

Kenji Shimoyama

Satoru Nagao

Kazumasa Kiyomi

Toshinari Fujimori

Nobuyuki Hosoi

Yoshihito Sato

Katsushi Fujii

Atsunori Yamauchi

Hideyoshi Horie

Masahiro Noguchi

Yuichi Inoue

Yoshihiro Suzuki

Hiroyoshi Yajima

The semiconductor device according to the present invention comprises a V-groove having V-shaped cross-section formed on a semiconductor substrate or on an epitaxial growth layer grown on a semiconductor substrate, and an active layer is provided only at the bottom of said V-groove. The method for manufacturing a semiconductor device according to the present invention comprises the steps of forming a stripe-like etching protective film in <011> direction of a semiconductor substrate or an epitaxial growth layer grown on it, performing gas etching using hydrogen chloride as etching gas on a semiconductor substrate or on an epitaxial growth layer grown on a semiconductor substrate to form a V-groove, and forming an active layer at the bottom of said V-groove.

Semiconductor device and method for manufacturing the same

The present invention provides a semiconductor light-emitting device including a first clad layer comprising a first conductive type of AlGaAsP compound, a second clad layer that is located next to the first clad layer, comprises a first conductive type of AlGaInP compound and has a thickness of up to 0.5 &mgr;m, an active layer that is located next to the second clad layer and comprises a first or second conductive type AlGaInP or GaInP, a third clad layer that is located next to the active layer, comprises a second conductive type of AlGaInP compound and has a thickness of up to 0.5 &mgr;m, and a fourth clad layer that is located next to the third clad layer and comprises a second conductive type of AlGaAsP compound, and/or a light-extracting layer that comprises a second conductive type AlGaP or GaP and has a thickness of 1 &mgr;m to 100 &mgr;m.

Semiconductor light-emitting devices

The invention provides a semiconductor device having a structure wherein a layer comprising at least Al.sub.W Ga.sub.1-W As is formed on a substrate and a second etching stop layer, a first etching stop layer and a layer comprising Al.sub.Y Ga.sub.1-Y As are deposited on the layer comprising Al.sub.W Ga.sub.1-W As in the described order, with a portion of the layer comprising Al.sub.Y G.sub.1-Y As and a portion of the first etching stop layer being removed. This structure enables a desired ridge shape to be fabricated with good quality and allows for free selection of the Al mixed crystal ratio of the layer to be etched, and makes it possible to form the re-growth interface of GaAs. Thus, the qualty of crystal of the re-grown portion can be improved.

Semiconductor device having a ridge or groove

A vapor phase growth process for the fabrication of a thin film form of compound semiconductor of elements of Groups III-V, using a halogen element-free hydride and a halogen element-free organic metal as the source materials for growth, is characterized in that a halide gas and/or a halogen gas that are free from the mother elements of the compound to be grown are added to the reaction atmosphere while the compound is growing. A trace amount(s) of the halide and/or halogen gas(es) that are free from the mother elements of the compound to be grown, such as HCl, is added to the reaction atmosphere while the compound is growing, thereby making it possible to flatten the heterojunction interface or effect the growth of high-quality crystals without deposition of polycrystals on a mask over a wide range.

Compound semiconductor and its fabrication

The present invention provides a semiconductor light-emitting device including a first clad layer comprising a first conductive type of AlGaAsP compound, a second clad layer that is located next to the first clad layer, comprises a first conductive type of AlGaInP compound and has a thickness of up to 0.5 .mu.m, an active layer that is located next to the second clad layer and comprises a first or second conductive type AlGaInP or GaInP, a third clad layer that is located next to the active layer, comprises a second conductive type of AlGaInP compound and has a thickness of up to 0.5 .mu.m, and a fourth clad layer that is located next to the third clad layer and comprises a second conductive type of AlGaAsP compound, and/or a light-extracting layer that comprises a second conductive type AlGaP or GaP and has a thickness of 1 .mu.m to 100 .mu.m.

In a wide band cap semiconductor, a GaP.sub.x N.sub.1-x (0.1.ltoreq.x.ltoreq.0.9) layer is inserted between a layer comprising AlGaInN and an electrode, The potential barrier between the electrode and the surface layer can be reduced. Contact resistance can be decreased, and ohmic contact can be easily taken up.

Semiconductor device having contact resistance reducing layer

The disclosure describes a laser diode comprising a Group III-V compound single-crystal substrate of first conduction type; a first cladding layer of first conduction type composed of (Al.sub.m Ga.sub.1-m).sub.n In.sub.1-n P (0.3.ltoreq.m.ltoreq.1 and 0.3.ltoreq.n.ltoreq.0.75) and formed on said single-crystal substrate; an active layer composed of (Al.sub.x Ga.sub.1-x).sub.y In.sub.1-y P (0.ltoreq.x.ltoreq.0.5 and 0.3.ltoreq.y.ltoreq.0.75) and formed on said first cladding layer; a second cladding layer of second conduction type composed of (Al.sub.m Ga.sub.1-m).sub.n In.sub.1-n P (0.3.ltoreq.m.ltoreq.1 and 0.3.ltoreq.n.ltoreq.0.75) and formed on said active layer and having a ridge; and a current blocking layer composed of Al.sub.u Ga.sub.1-u As.sub.v P.sub.1-v, (0.ltoreq.u.ltoreq.1 and 0.ltoreq.v.ltoreq.1) and so formed as to contact the lateral side of the ridge of said second cladding layer, (1) each refractive index of the first and second cladding layers being smaller than that of the active layer and (2) the refractive index of the current blocking layer being smaller than that of the second cladding layer.

Laser diode and process for producing the same

In a process for fabricating a semiconductor laser by forming a double-heterostructure made up of a first cladding layer, an active layer and a second cladding layer on a semiconductor substrate at the first growth step, forming protecting films for selective growth on both sides of a striped region for current injection, without etching the second cladding layer, and growing a third cladding layer and a contact layer for current injection at a second growth step, the second cladding layer formed at the first growth step is grown to the thickness required for achieving laser characteristics.

Fabrication of semiconductor laser elements

Carrier injection layers are formed on an Al.sub.x Ga.sub.1-x As clad layer of high resistance by embedding and re-growth with the use of crystal growth processes such as MO-VPE or MO-MBE where material supply sources are all provided by gas sources, whereby it is not required to mesa-etch embedding regions to a depth reaching a substrate. The formation of any separate blocking layer is dispensed with, any possible influence of the substrate is elminated, and the time constant is decreased by decreasing the inter-electrode capacity.

Method of making semiconductor laser devices

Disclosed is a divided electrode type semiconductor layer device designed to improve the separation of electrodes without reducing the amount of doping for carrier injection layers. A double-hetero-structure is formed on a semi-insulating substrate, and at least two pairs of carrier injection clad layers are thereafter buried like lands while a high-resistance portion is left between the carrier injection clad layers to electrically separate these layers. The electrodes are respectively formed on the separated carrier injection layers.

Divided electrode type semiconductor laser device

Carrier injection layers are formed on an Al.sub.x Ga.sub.1-x As clad layer of high resistance by embedding and re-growth with the use of crystal growth processes such as MO-VPE or MO-MBE where material supply sources are all provided by gas sources, whereby it is not required to mesa-etch embedding regions to a depth reaching a substrate. The formation of any separate blocking layer is dispensed with, any possible influence of the substrate is eliminated; and the time constant is decreased by decreasing the inter-electrode capacity.

Semiconductor laser devices

An epitaxial layer having a double-hetero structure is forming using an MOCVD process or an MBE process, and an epitaxial substrate is formed using an LPE process, thereby forming a substrate which exploits the distinguishing features of both processes. Since the MOCVD process or MBE process exhibits mixed-crystal ratio and film thickness controllability, excellent reproducibility and uniformity are obtained when forming the double-hetero structure on a compound semiconductor substrate. Since the growth process takes place under thermal non-equilibrium, the amount of impurity doping is raised to more than 10.sup.19 cm.sup.3. This is advantageous in terms of forming an electrode contact layer. With the LPE process, the material dissolved in the melt is grown epitaxially on the substrate by slow cooling, and the rate of growth is high. This process is suitable for forming the substrate after removal of the compound semiconductor substrate. By virtue of this liquid phase epitaxy, an oxide film preventing layer is removed by raising the degree of unsaturation of the melt, the epitaxial layer is grown in a short period of time, and a high-quality, highly uniform epitaxial substrate can be quickly manufactured. It is also possible to reduce cost.

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Ushiku, Japan

Hideki Gotoh