Abstract:
A multi−beam semiconductor laser element (40) which provides a uniform light output from each beam, for ease of positioning, and which is a GaN multi−beam semiconductor laser element having four laser stripes (42A, 42B, 42C, 42D) emitting laser beams of the same wavelength. Each laser stripe (42A−42D) has a p−side common electrode (48) on a mesa (46) formed on a sapphire substrate (44), and respective laser stripes have respective active regions (50A, 50B. 50C, 50D). Two n−side electrodes (52A, 52B) are provided on an n−type GaN contact layer (54) on the opposite sides of the mesa (46) as common electrode facing the p−side common electrode (48). The distance A between the laser stripe (42A) and the laser stripe (42D) is up to 100 μm. The distance B 1 between the laser stripe (42A) and the laser−side end of the n−side electrode (52B) is up to 150 μm, and the distance B 2 between the laser stripe (42D) and the laser−side end of the n−side electrode (52A) is up to 150 μm.
Abstract:
A film of a II - VI group compound semiconductor of at least one of elements belonging to the II group of the periodic table and at least one of elements belonging to the VI group of the periodic table is deposited on a substrate. When the film is deposited on the substrate, a plasma of nitrogen in an excited state is applied to the substrate while removing charged particles from said plasma by a charged particle removing means. The deposited film of a nitrogen-doped II - VI group compound semiconductor has an increased percentage of activated nitrogen atoms and improved crystallinity.
Abstract:
A multi-junction solar cell that is lattice-matched with a base, and that includes a sub-cell having a desirable band gap is provided. It includes a plurality of sub-cells 11, 12, 13, and 14 that are laminated, and each include a first compound semiconductor layer and a second compound semiconductor layer that are laminated. At least one predetermined sub-cell 11 is configured of first layers 11A 1 and 11A 2 and a second layer 11C. In each of the first layers 11A 1 and 11A 2 , a 1-A layer 11A A and a 1-B layer 11A B are laminated. In the second layer 11C, a 2-A layer 11C A and a 2-B layer 11C B are laminated. A composition A of the 1-A layer 11A A and the 2-A layer 11C A is determined based on a value of a band gap of the predetermined sub-cell 11. A composition B of the 1-B layer 11A B and the 2-B layer 11C B is determined based on a difference between a base lattice constant of the base and a lattice constant of the composition A. Thicknesses of the 1-B layer 11A B and the 2-B layer 11C B are determined based on a difference between the base lattice constant and a lattice constant of the composition B, and on the thickness of the 1-A layer 11A A and the thickness of the 2-A layer 11C A .
Abstract:
A multi-beam semiconductor laser device capable of emitting respective laser beams with uniform optical output levels and enabling easy alignment is provided. This multi-beam semiconductor laser device (40) is a GaN base multi-beam semiconductor laser device provided with four laser stripes (42A, 42B, 42C and 42D) which are capable of emitting laser beams with the same wavelength. The respective laser oscillating regions (42A to 42D) are provided with a p-type common electrode (48) on a mesa structure (46) which is formed on a sapphire substrate (44), and have active regions (50A, 50B, 50C and 50D) respectively. Two n-type electrodes (52A and 52B) are provided on an n-type GaN contact layer (54) and located as common electrodes opposite to the p-type common electrode (48) on both sides of the mesa structure (46). The distance A between the laser stripe (42A) and the laser stripe (42D) is no larger than 100 mu m. The distance B1 between the laser stripe (42A) and the n-type electrode (52B) is no larger than 150 mu m while the distance B2 between the laser stripe (42D) and the n-type electrode (52A) is no larger than 150 mu m.
Abstract:
A method for growing nitride III-V compound semiconductor layers, comprises the steps of: growing a first BwAlxGayInzN layer (where 0≤w≤1, 0≤x≤1, 0≤y≤1, 0≤z≤1 and w+x+y+z=1) on a substrate by first vapor deposition at a growth rate not higher than 4 mu m/h; and growing a second BwAlxGayInzN layer (where 0≤w≤1, 0≤x≤1, 0≤y≤1, 0≤z≤1 and w+x+y+z=1) on the first BwAlxGayInzN layer by second vapor deposition at a growth rate higher than 4 mu m/h and not higher than 200 mu m/h. A method for fabricating a nitride III-V compound semiconductor substrate, comprises the steps of: growing a first BwAlxGayInzN layer (where 0≤w≤1, 0≤x≤1, 0≤y≤1, 0≤z≤1 and w+x+y+z=1) on a substrate by first vapor deposition at a growth rate not higher than 4 mu m/h; growing a second BwAlxGayInzN layer (where 0≤w≤1, 0≤x≤1, 0≤y≤1, 0≤y≤1 and w+x+y+z=1) on the first BwAlxGayInzN layer by second vapor deposition at a growth rate higher than 4 mu m/h and not higher than 200 mu m/h; and removing the substrate.
Abstract:
A film of a II - VI group compound semiconductor of at least one of elements belonging to the II group of the periodic table and at least one of elements belonging to the VI group of the periodic table is deposited on a substrate. When the film is deposited on the substrate, a plasma of nitrogen in an excited state is applied to the substrate while removing charged particles from said plasma by a charged particle removing means. The deposited film of a nitrogen-doped II - VI group compound semiconductor has an increased percentage of activated nitrogen atoms and improved crystallinity.
Abstract:
A multi-beam semiconductor laser device capable of emitting respective laser beams with uniform optical output levels and enabling easy alignment is provided. This multi-beam semiconductor laser device (40) is a GaN base multi-beam semiconductor laser device provided with four laser stripes (42A, 42B, 42C and 42D) which are capable of emitting laser beams with the same wavelength. The respective laser oscillating regions (42A to 42D) are provided with a p-type common electrode (48) on a mesa structure (46) which is formed on a sapphire substrate (44), and have active regions (50A, 50B, 50C and 50D) respectively. Two n-type electrodes (52A and 52B) are provided on an n-type GaN contact layer (54) and located as common electrodes opposite to the p-type common electrode (48) on both sides of the mesa structure (46). The distance A between the laser stripe (42A) and the laser stripe (42D) is no larger than 100 mu m. The distance B1 between the laser stripe (42A) and the n-type electrode (52B) is no larger than 150 mu m while the distance B2 between the laser stripe (42D) and the n-type electrode (52A) is no larger than 150 mu m.
Abstract:
A MOLECULAR BEAM EPITAXY SYSTEM (1) HAVING A PLURALITY OF CHAMBERS WHICH CONTAIN AT LEAST A FIRST CHAMBER (12) AND A SECOND CHAMBER (13). THE FIRST CHAMBER (12) IS USED TO FORM II-VI COLUMN COMPOUND SEMICONDUCTOR LAYERS NOT CONTAINING TE. THE SECOND CHAMBER (13) IS USED TO FORM II-VI COLUMN COMPOUND SEMICONDUCTOR LAYERS CONTAINING AT LEAST TE. A SEMICONDUCTOR DEVICE HAVING AN OHMIC CHARACTERISTICS CAN BE FABRICATED WITHOUT MIXING TE INTO OTHER LAYERS.
Abstract:
A semiconductor laser is formed into a double hereto junction structure comprising an n-type cladding layer (3) and a p-type cladding layer (5) with an active layer (4) interposed therebetween. The p-type cladding layer (5) has a laminated structure consisting of a first cladding layer (51) of (AlxGa1-x)InP disposed on one side adjacent to the active layer (4) and a second cladding layer (52) of AlyGa1-yAs disposed on the reverse side. A deterioration preventive layer (11) of AlzGa1-yAs is included in the first cladding layer (51) at a position spaced apart from the second cladding layer (52) by a predetermined distance. In addition, the second cladding layer (52) is partially removed, and a current stricture layer (10) is formed in such removed portion.