Abstract:
PROBLEM TO BE SOLVED: To grow a good quality single-crystalline, nitride-based III-V semiconductor. SOLUTION: A layer of laminated substance is grown on a substrate by a molecular beam epitaxy process or the like, and then a nitride III-V compound semiconductor is grown on the laminated substance layer. As the substrate GaAs substrate 1 or an Si substrate is sued. Dangling bonds on the substrate are terminated beforehand preferably prior to the growth of the laminated substance layer. As the laminated substance a transition metal dichalcogenide such as MoS2 , graphite, mica, or the like is used. The nitride-based III-V compound semiconductor is used in the manufacture of semiconductor lasers, light- emitting diodes, field effect transistors(FET), etc.
Abstract:
PROBLEM TO BE SOLVED: To realize a method for growing a III-V nitride compound semiconductor having high crystallinity by increasing nitrogen materials contributing to growth. SOLUTION: A material gas, including ammonia gas being the material of nitrogen and carrier gas, is supplied inside of a reaction tube 3. The flow of the material gas inside the reaction tube 3 is set in a direction, parallel to the growth surface of a substrate 14, and the velocity of flow of the material gas inside the reaction tube 3 is set at 2 m/s or less. Thus, ammonia can be fully heated by the delay amount of the velocity of flow, and decomposing efficiency can be improved, and the supply of the nitrogen material to the growth surface of the substrate 14 can be increased, and the evaporation of nitrogen from the III-V nitride compound semiconductor during growth can be suppressed. Also, it is desirable that the inside the reaction tube 3 be pressurized.
Abstract:
PROBLEM TO BE SOLVED: To provide a growing method of a nitride-based group III-V compound semiconductor layer capable of growing the nitride group III-V compound semiconductor layer on a substrate with good crystal quality. SOLUTION: When a GaN layer is grown on a substrate by a chemical vapor deposition method, and an AlGaN layer is grown on this GaN layer by the chemical vapor deposition method, the GaN layer is grown, with the molar ratio of a supply amount of a raw material N to the supply amount of a raw material of Ga set at ≥8,000, preferably ≥10,000, and more preferably ≥11,000. An Al 2 O 3 substrate, a ZnO substrate, and a SiC substrate are used as a substrate. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To reduce streaks on image generated by the fluctuations of manufacturing a one-dimensional type optical modulation device. SOLUTION: In the image projection apparatus, a main scanning optical part 108, which is scanned in a direction substantially vertical to the longitudinal direction of the one-dimensional type optical modulation device and a subscanning optical part 107, which is scanned in the longitudinal direction of the one-dimensional type optical modulation device are disposed on a scanning optical part 130. By vertically moving a one-dimensional image, for example, each frame, by means of the subscanning optical part 107, lateral streaks of the image can be suppressed or avoided. Also, optical face tangle errors of a polygon mirror can be corrected. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a semiconductor light emitting element using such a III-V nitride compound semiconductor that can reduce the threshold current density by hardly raising the operating voltage. SOLUTION: The p-type clad layer of a GaN semiconductor laser is constituted of two or more semiconductor layers having different band gaps and, in addition, the part of the p-type clad layer near the active layer-side interface of the layer is constituted of a semiconductor layer having a larger band gap than the other part has. To be concrete, in the GaN semiconductor laser having an AlGaN/GaN/GaInN SCH structure, the p-type AlGaN clad layer 10 is constituted of a p-type Alx1Ga1-x1N layer 10a which is in contact with a p-type GaN optical waveguide layer 9 and a p-type Alx2Ga1-x2N layer 10b (0
Abstract:
PROBLEM TO BE SOLVED: To provide a method for growing a p-type nitride III-V compound semiconductor which has less crystal defects and good quality. SOLUTION: A MOCVD device 10 for implementing this method has a reaction tube 14 having inside thereof a suscepter 12 holding a substrate W, and a bubbler 20A housing TMG(trimethylgallium) and adapted for supplying a TMG gas to the reaction tube 14 through a supply line 18 by bubbling with a hydrogen gas. The substrate W is set in the reaction tube 14, and the temperature is raised to 1000 deg.C. Then, a hydrogen gas is supplied to the bubbler 20A, thereby introducing the TMG gas into the reaction tube 14. A GaN:C crystal to which a carbon atom as a p-type dopant is introduced is epitaxially grown on the substrate W. As a result, a GaN:C crystal of good quality having less crystal defects is provided.
Abstract:
PROBLEM TO BE SOLVED: To provide a semiconductor saturable absorber mirror which has polarization axis dependence of a beam absorbing characteristic and provides a stable polarizing characteristic, and also to provide a laser beam generator using the semiconductor saturable absorber mirror. SOLUTION: The semiconductor saturable absorber mirror is produced by allowing a reflection mirror layer 12 made of DBR to grow on an inclined substrate 11 and also by allowing a semiconductor quantum well layer 13 on the mirror layer to grow as a saturable absorbing layer including a strained quantum well. An asymmetric strain is produced in the surface of the strained quantum well of the semiconductor quantum well layer 13. A GaAs substrate, an InP substrate, a GaN substrate, an Al 2 O 3 substrate, or the like is used as the inclined substrate 11. The semiconductor saturable absorber mirror is used for a resonator mirror of the laser beam generator. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To reduce the stripe of an image caused by variation in manufacturing a diffraction grating type optical modulator. SOLUTION: An image projection device is equipped with: a light source 100; a diffraction grating type optical modulator 102; and a projection optical system 110, and is provided with a driving part 103 moving the optical modulator 102 in the grating array direction (arrow m) of the diffraction grating of the optical modulator 102, and provided with a signal processing part 200 compensating an image signal input in the optical modulator 102 according to the moving direction of the optical modulator 102. By moving the optical modulator 102 by one to several pixels in every non-display period of one frame, a horizontal stripe caused by the variation in manufacturing is prevented and image quality is improved. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To enhance uniformity concerning the light intensity distribution of an illumination optical system and also to restrain the lowering of efficiency caused by interference so as to control the lowering of luminance to the minimum. SOLUTION: In the prism element 1 used for uniformizing the light intensity distribution, a second surface 2_2 being a polarized light branching surface is arranged between a first surface 2_1 and a third surface 2_3 being reflection surfaces. The first and the third surfaces are arranged in parallel or nearly in parallel with each other, and incident light is emitted passing through an optical path where it is branched by the second surface 2_2 after it is reflected by the first surface 2_1 and an optical path where it is directly branched by the second surface 2_2. The luminous fluxes divided into four in the prism element 1 are composed, thereby obtaining averaged light quantity distribution. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To prevent deterioration of a nitride-based group III-V compound semiconductor layer, containing In and to improve the quality of the nitride-based group III-V compound semiconductor layer that does not contain In, when the nitride-based group III-V compound semiconductor layer that does not contain In is grown on the nitride-based group III-V compound semiconductor layer containing In, such as GaInN layer at a higher growth temperature than that of the latter layer. SOLUTION: A protective film composed of AlGaN is grown on the nitride-based group III-V compound semiconductor layer, containing In at a growth temperature almost equal to or lower than that of the semiconductor layer thereof, and the nitride-based III-V compound semiconductor layer that does not contain In is grown thereon. Here, N 2 is used as the carrier gas, when the nitride-based group III-V compound semiconductor layer containing In and the protecting film are grown, and a mixed gas of H 2 and N 2 is used for the carrier gas, when the nitride-based group III-V compound semiconductor layer that does not contain In is grown. COPYRIGHT: (C)2006,JPO&NCIPI