An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

An object is to provide a method for manufacturing a semiconductor device, in which the number of photolithography steps can be reduced, the manufacturing process can be simplified, and manufacturing can be performed with high yield at low cost A method for manufacturing a semiconductor device includes the following steps: forming a semiconductor film; irradiating a laser beam by passing the laser beam through a photomask including a shield for shielding the laser beam; subliming a region which has been irradiated with the laser beam through a region in which the shield is not formed in the photomask in the semiconductor film; forming an island-shaped semiconductor film in such a way that a region which is not irradiated with the laser beam is not sublimed because it is a region in which the shield is formed in the photomask; forming a first electrode which is one of a source electrode and a drain electrode and a second electrode which is the other one of the source electrode and the drain electrode; forming a gate insulating film; and forming a gate electrode over the gate insulating film

Method for Manufacturing Semiconductor Device

A detector (110) for optically detecting at least one object (112) is proposed. The detector (110) comprises at least one optical sensor (114). The optical sensor (114) has at least one sensor region (116). The optical sensor (114) is designed to generate at least one sensor signal in a manner dependent on an illumination of the sensor region (116). The sensor signal, given the same total power of the illumination, is dependent on a geometry of the illumination, in particular on a beam cross section of the illumination on the sensor area (118). The detector (110) furthermore has at least one evaluation device (122). The evaluation device (122) is designed to generate at least one item of geometrical information from the sensor signal, in particular at least one item of geometrical information about the illumination and/or the object (112).

Detector for optically detecting at least one object

Graded-refractive-index-rod lenses (GRIN-rod lenses) have a number of features that make them particularly suitable for use in optical devices for manipulating and processing the optical signals in fiber communication systems. Such lenses can be cemented directly to the other elements of a device, thus giving a structure that is compact, solid, stable, and rugged. They also have significantly smaller aberrations than equivalent simple homogeneous lenses, and this results in lower insertion losses. Designs for various GRIN-rod lens devices, including connectors, attenuators, directional couplers, switches, isolators and wavelength-division multiplexers are reviewed. A consistent set of loss estimates is provided for all the device designs considered.

Applications of GRIN-rod lenses in optical fiber communication systems.

Respective end faces of two or more optical waveguides (23 to 29) are connected on one end face of a focussing rod lens (20) and a reflection means (21) having a reflection plane tilted with a specified angle (α) to the normal plane to the lens axis is disposed behind the other end face of the focussing rod lens (20) and angle of reflection plane of the reflection means (21) is varied by rotating the reflection means (21) around the lens axis (203) or by means of a piezo-electric driving device (30), thereby attaining selective switching of the waveguides (from 23 to selected one of 24 or 29) or varying the amount of rays to be transmitted through the waveguides (23 and 24 of FIG. 4), or thereby modulating the rays. By utilizing a semitransparent filter forming another tilted reflection plane, the amount of attenuation for different wavelength or connection of the waveguides are controlled separately.

Optical switching device

PURPOSE:To enable the growth of crystal in only two processes by a method wherein a stripe-like waveguide layer is formed on a waveguide region and an active region, an active layer is made to grow, the active layer around the waveguide layer stripe is selectively removed, and the side of the waveguide layer is filled through a mass transport method CONSTITUTION:A waveguide layer 2a whose forbidden bandwidth is small than that of a substrate is formed on a first conductivity type semiconductor substrate 1, and then the layer 2a is processed to form into two parallel mesa stripes and another mesa stripe connected to them Next, an active layer 3, whose forbidden bandwidth is smaller than that of the waveguide layer, and a clad layer 4 and a contact layer 5, whose forbidden bandwidths are larger than that of the waveguide layer, are successively made to grow Then, a stripe pattern broader than the stripe of the waveguide layer is formed, and the contact layer 5, the clad layer 4, and the active layer 3 are selectively removed Then, when the substrate 1 is thermally treated in a phosphorus atmosphere at a high temperature, the constricted part at the lower part of a ridge is filled with a semiconductor layer 6 whose forbidden bandwidth is larger than that of the waveguide layer through mass transport Lastly, the formation of a semiconductor laser of this design is completed through the formation of an SiO2 film 7 for an electrode stripe and the evaporation of a p-side electrode 8 and an n-side electrode 9

Manufacture of semiconductor laser

A new type of optical switch is constructed of graded-index rod lenses. It is operated mechanically by small electromagnets. This switch is compatible with practical multimode-fiber communication systems. It has many outstanding features, such as low insertion loss (1.3–1.4 dB), low crosstalk ( 2 × 106 times), and small size (40 × 50 × 25 mm3).

Optical switch for multimode optical-fiber systems.

PURPOSE:To obtain multiple wavelengths, by integrating a plurality of semiconductor laser elements, which comprise quantum-well active layers having respective different inner losses, on one chip CONSTITUTION:Stripe widths of optical waveguides 25a, 25b, and 25c in a quantum-well active layer 20 are formed to be, for example, 05mum, 2mum, and 5mum, respectively, so that internal loss of a resonator has variety The smaller the stripe widths are formed, the higher the loss of the resonator becomes These internal losses alpha25a, alpha25b, alpha25c have the following relation: alpha25a>alpha25b>alpha25c When current is then injected into this semiconductor laser array, gain at the wavelength corresponding on the n=1 quantum level which is the lowest becomes larger than the loss (alpha25c) on the optical waveguide 25c, so that laser beams of wavelength lambda1 are oscillated On the optical waveguide 25b, no oscilllation occurs on the n=1 level, the gain at the wavelength corresponding on the n=2 quantum level becomes larger than the loss (alpha25b), so that laser beams of wavelength lambda2 (<lambda1) are oscillated In the optical waveguide 25a, no oscillation on the n=1 and n=2 levels, and the gain at the wavelength corresponding on the n=3 quantum level becomes larger than the loss alpha25a, so that laser beams of wavelength lambda3 (<lambda2<lambda1) are oscillated

Semiconductor laser array

Un laser a semiconducteurs comprend un substrat semiconducteur 1, une couche de reseau de diffraction 2a formee par croissance sur le substrat et consistant en un materiau ayant une bande d'energie interdite inferieure a celle du substrat, des sillons a bandes paralleles de periode predeterminee qui atteignent le substrat et sont formes sur la totalite de la surface de la couche de reseau de diffraction 2a, une couche de barriere 4 ayant la meme composition que le substrat, une couche active 5 ayant une bande d'energie interdite inferieure a celle de la couche de reseau de diffraction, et un reseau de diffraction qui est constitue par la partie restante de la couche de reseau de diffraction.

Laser a semiconducteurs

PURPOSE: To generate laser oscillation on respective quantum levels, by forming an active layer in multiple quantum-wells having barrier width narrowed and electronic states combined and besides by composing plural semiconductor laser elements, which have the similar resonator lengths and the regions where carriers different in size can be injected, on the similar substrate. CONSTITUTION: Cleavage planes 12 and 13 compose a Fabry-Perot resonator. Diffused p-type dopants form a striped waveguide, which runs in parallel with the axis of the resonator, in quantum-well layers. This stripe width is made small because light through the waveguide is more absorbed by free carriers in the diffusion region in the vicinity of the guided-wave path. The lengths LA,LB, and LC in the resonator-length directions of electrodes 4A, 4B, and 4C, become small in the order of them, and LA is equal to the resonator length. If the lengths LA, LB,and LC of the respective electrodes are set up to be ones in which laser oscillation on the respective levels can be generated, laser beams with respective different wavelengths can be oscillated. COPYRIGHT: (C)1988,JPO&Japio

Matsui Teruhito

Papers

Manufacture of semiconductor laser

Optical switch for multimode optical-fiber systems.

Semiconductor laser array

Laser a semiconducteurs

Integrated semiconductor laser