Sumitomo Electric Industries, Limited

Kenji Hiratsuka

Takeyoshi Masuda

Yoshihiro Yoneda

Yu Saitoh

Masaki Yanagisawa

Kenji Koyama

Hirohiko Kobayashi

Hideki Yagi

Tomokazu Katsuyama

Mitsuo Takahashi

Toshio Nomaguchi

Nobuyuki Ikoma

Manabu Yoshimura

Akiko Kumagai

Kouichiro Yamazaki

A trench having an opening and a corner portion is formed in a silicon carbide substrate. A corner insulating film is formed to cover the corner portion. A gate insulating film is formed to cover a region extending from the opening to the corner portion. The step of forming the gate insulating film includes a step of thermally oxidizing the trench provided with the corner insulating film. The step of thermally oxidizing the trench includes a step of heating the silicon carbide substrate at not less than 1300&#xb0; C. Accordingly, sufficient insulation reliability of the gate insulating film is secured near the opening of the trench while preventing dielectric breakdown of the gate oxide film at the bottom portion of the trench.

Method for manufacturing silicon carbide semiconductor device having trench

A silicon carbide substrate has first to third semiconductor layers. The first and third semiconductor layers have a first conductivity type, and the second semiconductor layer has a second conductivity type. A trench has a bottom surface and first to third side surfaces, the bottom surface being constituted of the first semiconductor layer, the first to third side surfaces being respectively constituted of the first to third semiconductor layers. A gate insulating film having a bottom portion and a side wall portion is provided on the trench. The bottom portion has a minimum thickness d. A portion of the side wall portion on the second side surface has a minimum thickness d. A portion, connected to the bottom portion, of the side wall portion on the first side surface has a thickness d. Moreover, d&#x3e;dand d&#x3e;dare satisfied.

Method for manufacturing silicon carbide semiconductor device and silicon carbide semiconductor device

A semiconductor optical integrated device includes a substrate having a main surface with a first and second regions arranged along a waveguiding direction; a gain region including a first cladding layer, an active layer, and a second cladding layer arranged on the first region of the main surface; and a wavelength control region including a third cladding layer, an optical waveguide layer, and a fourth cladding layer arranged on the second region of the main surface and including a heater arranged along the optical waveguide layer. The substrate includes a through hole extending from a back surface of the substrate in the thickness direction and reaching the first region. A metal member is arranged in the through hole. The metal member extends from the back surface of the substrate in the thickness direction and is in contact with the first cladding layer.

Semiconductor optical integrated device

A method for manufacturing a semiconductor optical device includes the steps of growing a stacked semiconductor layer on a substrate having a cleavage direction in a first direction; forming a first mask having a plurality of openings arranged in the first direction; forming a mark array by etching the stacked semiconductor layer using the first mask; forming a second mask having first and second openings extending in a second direction intersecting the first direction; obtaining a substrate product by forming first and second grooves, and a waveguide mesa by etching the stacked semiconductor layer by using the second mask; and producing a laser diode bar by cleaving the substrate product including the waveguide mesa. First and second residual marks are formed on the upper surface of the waveguide mesa. First and second transfer marks are formed on the bottoms of the first and the second grooves, respectively.

Method for manufacturing semiconductor optical device and semiconductor optical device

A silicon carbide substrate is prepared which has a main surface covered with a silicon dioxide layer. In the silicon dioxide layer, an opening is formed by etching. In the opening, a residue resulting from the etching is on the silicon carbide substrate. The residue is removed by plasma etching in which only an inert gas is introduced. After removing the residue, under heating, a reactive gas is supplied to the silicon carbide substrate covered with the silicon dioxide layer having the opening formed therein. In this way, a trench is formed in the main surface of the silicon carbide substrate.

Method for manufacturing silicon carbide semiconductor device

A method for producing an integrated optical device includes the steps of growing, on a substrate including first and second regions, a first stacked semiconductor layer, a first cladding layer, and a side-etching layer; etching the first stacked semiconductor layer through a first etching mask formed on the first region; selectively growing, on the second region, a second stacked semiconductor layer and a second cladding layer; growing a third cladding layer and a contact layer on the first and second stacked semiconductor layers; and forming a ridge structure. The step of etching the first stacked semiconductor layer includes a step of forming an overhang between the first cladding layer and the first etching mask. The step of forming a ridge structure includes first, second, and third wet-etching steps in which the third cladding layer, the side-etching layer and the first and second cladding layers are selectively etched, respectively.

Method for producing integrated optical device

A method for producing a semiconductor optical integrated device includes the steps of forming a substrate product including first and second stacked semiconductor layer portions; forming a first mask on the first and second stacked semiconductor layer portions, the first mask including a stripe-shaped first pattern region and a second pattern region, the second pattern region including a first end edge; forming a stripe-shaped mesa structure; removing the second pattern region of the first mask; forming a second mask on the second stacked semiconductor layer portion; and selectively growing a buried semiconductor layer with the first and second masks. The second mask includes a second end edge separated from the first end edge of the first mask, the second end edge being located on the side of the second stacked semiconductor layer portion in the predetermined direction with respect to the first end edge of the first mask.

Method for producing semiconductor optical integrated device

A method for producing a semiconductor optical device includes a first etching step of etching a stacked semiconductor layer with a first mask to form a stripe-shaped optical waveguide, the stripe-shaped optical waveguide including first and second stripe-shaped optical waveguides formed on first and second regions of a substrate, respectively; a step of forming a second mask on the stacked semiconductor layer with the first mask left; and a second etching step of etching the stacked semiconductor layer on the first region with the first and second masks. The second mask has a pattern for forming a mesa structure and includes an opening including first and second opening edges remote from side surfaces of the first stripe-shaped optical waveguide. The mesa structure is formed of the first stripe-shaped optical waveguide in the second etching step. The second stripe-shaped optical waveguide formed in the first etching step has a ridge structure.

Method for producing semiconductor optical device

A method of making a semiconductor optical integrated device includes the steps of forming, on a substrate, a plurality of semiconductor integrated devices including a first optical semiconductor element having a first bonding pad and a second optical semiconductor element; forming a plurality of bar-shaped semiconductor optical integrated device arrays by cutting the substrate, each of the semiconductor optical integrated device arrays including two or more semiconductor optical integrated devices; alternately arranging the plurality of semiconductor optical integrated device arrays and a plurality of spacers in a thickness direction of the substrate so as to be fixed in place; and forming a coating film on a facet of the semiconductor optical integrated device array. Furthermore, the spacer has a movable portion facing the first bonding pad, the movable portion protruding toward the first bonding pad and being displaceable in a protruding direction.

Method of making semiconductor optical integrated device by alternately arranging spacers with integrated device arrays

A method for producing a semiconductor optical device, includes the steps of: (a) forming a semiconductor region on a substrate, the substrate including first and second areas; the first area including device sections (b) forming a first mask on the semiconductor region, the first mask including first patterns periodically arranged in the first area and a second pattern provided in the second area; (c) forming a plurality of periodic structures in each of the device sections and a monitoring structure in the second area by using the first mask, the periodic structures respectively corresponding to the first patterns, the monitoring structure corresponding to the second pattern; (d) measuring a shape of the monitoring structure; (e) selecting a desired periodic structure from the plurality of periodic structures on a basis of a result of measuring the shape of the monitoring structure; (f) forming a second mask including a pattern on the desired periodic structure; and (g) forming stripe mesas including the desired periodic structure by using the second mask.

A substrate product is formed, and the substrate product includes a first region, a second region, a protrusion structure, and first and second scribe marks. The first region includes sections arranged in first and second axes to form an array, and the second region is provided adjacent to the array. The protrusion structure is provided in the second region; the first and second scribe marks are provided in the second region; the first and second scribe marks extend along first and second reference lines, respectively; and the first and second reference lines define boundary of the sections. After sandwiching the substrate product between films, a first cleavage of the substrate product is performed along the first scribe mark to form a first laser bar and another substrate product, and a second cleavage of the other substrate product is performed along the second scribe mark to form a second laser bar and still another substrate product. Each section includes a laser stripe extending in the direction of the first axis, the substrate product includes a semiconductor substrate and a semiconductor laminate for the semiconductor laser provided on the semiconductor substrate. The protrusion structure is provided on the first reference line.

Method of fabricating semiconductor laser

In a method of fabricating a semiconductor optical device, a semiconductor region is formed by growing an InP lower film, a active region, an InP upper film and a capping film on a substrate sequentially. Material of the capping film is different from that of InP. Next, a mask is formed on the capping film, and the semiconductor region is etched using the mask to form a semiconductor stripe mesa, which includes an InP lower cladding layer, a active layer, an InP upper cladding layer and a capping layer. The active layer comprises aluminum-based III-V compound. A width of the top surface of the capping layer is greater than that of a width of the bottom surface of the capping layer. A width of the top surface of the InP upper cladding layer is smaller than that of the bottom surface of the InP upper cladding layer. The minimum width of the semiconductor mesa is in the InP upper cladding layer. After forming the semiconductor stripe mesa, thermal process of the semiconductor mesa is carried out in an atmosphere to form a mass transport semiconductor on a side of the InP upper cladding layer, and the atmosphere contains V-group material.

Semiconductor optical device and method of fabricating the same

In the method of making a semiconductor laser, a semiconductor region is grown on an active layer, and a part of the semiconductor region is etched to form a ridge structure. An insulating film is formed over the ridge structure, and a resin layer of photosensitive material is formed to bury the ridge structure. A cured resin portion and an uncured resin portion are formed in the resin layer by performing lithographic exposure of the resin layer, and the uncured resin portion is on the top of the ridge structure. The uncured resin portion is removed to form a dent which is provided on the top of the ridge structure. An overall surface of the cured resin portion and dent is etched to form an etched resin layer. An opening is formed in the etched resin layer by thinning the cured resin portion, and a part of the insulating film is exposed in the opening of the etched resin layer. The part of the insulating film is etched using the etched resin layer as a mask to form an opening in the insulating film. An electrode is formed over the ridge structure and the etched resin layer.

Semiconductor laser and method of making the same

A new structure of a semiconductor optical device and a method to produce the device are disclosed. One embodiment of the optical device of the invention provides a blocking region including, from the side close to the mesa, a p-type first layer and a p-type second layer. The first layer is co-doped with an n-type impurity and a p-type impurity. The doping concentration of the p-type impurity in the first layer is smaller than that in the second layer, so, the first layer performs a function of a buffer layer for the Zn diffusion from the second layer to the active layer in the mesa structure.

Semiconductor light-emitting device and a method to produce the same

A light-emitting device with a protection layer for Zn inter-diffusion and a process to form the device are described. The device of the invention provides an active layer containing aluminum (Al) as a group III element, typically AlGaInAs, and protection layers containing silicon (Si) to prevent the inter-diffusion of zing (Zn) atoms contained in p-type layers surrounding the active layer. One of protection layers is put between the active layer and the p-type cladding layer, while, the other of protection layers is disposed between the active layer and the p-type burying layer.

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Yokohama, Japan

Kenji Hiratsuka