Abstract: An Si1−yGey layer (where 0<y<1), an Si layer containing C, a gate insulating film and a gate electrode are formed in this order on a semiconductor substrate. An Si/SiGe heterounction junction is formed between the Si and Si1−yGey layers. Since C is contained in the Si layer, movement, diffusion and segregation of Ge atoms in the Si1−yGey layer can be suppressed. As a result, the Si/Si1−yGey interface can have its structural disorder eased and can be kept definite and planar. Thus, the mobility of carriers moving along the interface in the channel can be increased. That is to say, the thermal budget of the semiconductor device during annealing can be improved. Also, by grading the concentration profile of C, the diffusion of C into the gate insulating film can be suppressed and decline in reliability can be prevented.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: A method for depositing a semiconductor film on a wafer by making a source gas supplied flow almost horizontally to the surface of the wafer. When a process condition, e.g., the flow velocity or pressure of the source gas, should be changed, the source gas has its velocity and/or pressure changed so that the source gas is supplied at a substantially constant flow rate.

Abstract: A method for depositing a semiconductor film on a wafer by making a source gas supplied flow almost horizontally to the surface of the wafer. When a process condition, e.g., the flow velocity or pressure of the source gas, should be changed, the source gas has its velocity and/or pressure changed so that the source gas is supplied at a substantially constant flow rate.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: The method for fabricating a semiconductor includes the steps of: (1) growing a first semiconductor layer made of AlxGa1−xN (0≦x≦1) on a substrate at a temperature higher than room temperature; and (2) growing a second semiconductor layer made of AluGavInwN (0<u≦1, 0≦v≦1, 0≦w≦1, u+v+w=1) over the first semiconductor layer. In the step (1), the mole fraction x of Al of the first semiconductor layer is set so that the lattice constant of the first semiconductor layer at room temperature substantially matches with the lattice constant of the second semiconductor layer in the bulk state after thermal shrinkage or thermal expansion.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: A semiconductor light-emitting device has first and second semiconductor layers each of a first conductivity type, a third semiconductor layer of a second conductivity type provided between the first and second semiconductor layers, and an active layer provided between the second and third semiconductor layers to emit light with charge injected therein from the second and third semiconductor layers. A graded composition layer is provided between the active layer and the third semiconductor layer to have a varying composition which is nearly equal to the composition of the active layer at the interface with the active layer and to the composition of the third semiconductor layer at the interface with the third semiconductor layer.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: A semiconductor light-emitting device with a double hetero structure, including: an active layer made of Ga.sub.1-x In.sub.x N (0.ltoreq.x.ltoreq.0.3) doped with a p-type impurity and an n-type impurity; and first and second cladding layers provided so as to sandwich the active layer.

Abstract: A semiconductor light-emitting device with a double hetero structure, including: an active layer made of Ga.sub.1-x In.sub.x N (0.ltoreq.x.ltoreq.0.3) doped with a p-type impurity and an n-type impurity; and first and second cladding layers provided so as to sandwich the active layer.

Abstract: A semiconductor laser device having an active layer, a pair of cladding layers interposing the active layer and a multi-quantum barrier provided between one of the pair of cladding layers and the active layer is provided, and the multi-quantum barrier includes barrier layers and well layers being alternated with each other. The semiconductor laser device also including an optical guide layer confining light generated in a quantum well layer, and the optical guide layer being undoped.

Abstract: A semiconductor laser according to the present invention includes: a semiconductor substrate; a multilayer structure provided on the semiconductor substrate, the multilayer structure including an active layer, a pair of cladding layers interposing the active layer, and current confining portion for injecting a current into a stripe-shaped predetermined region of the active layer, wherein the current confining portion includes a first current confining layer formed in regions excluding a region corresponding to the predetermined region of the active layer, the first current confining layer having an energy band gap larger than an energy band gap of the active layer and having a refractive index smaller than a refractive index of the active layer.

Abstract: A semiconductor light-emitting device with a double hetero structure, including: an active layer made of Ga.sub.1-x In.sub.x N (0.ltoreq.x.ltoreq.0.3) doped with a p-type impurity and an n-type impurity; and first and second cladding layers provided so as to sandwich the active layer.

Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: A semiconductor light-emitting device with a double hetero structure, including: an active layer made of Ga.sub.1-x In.sub.x N (0.ltoreq.x.ltoreq.0.3) doped with a p-type impurity and an n-type impurity; and first and second cladding layers provided so as to sandwich the active layer.

Abstract: A semiconductor laser device having an active layer, a pair of cladding layers interposing the active layer and a multi-quantum barrier provided between one of the pair of cladding layers and the active layer is provided. The multi-quantum barrier includes barrier layers and well layers being alternated with each other. Thickness, energy band gap, or impurity concentration of at least one of the barrier layers and well layers in the multi-quantum barrier changes with the distance from the active layer, thereby providing a stable function of reflecting carriers overflowing from the active layer back to the active layer.

Abstract: A semiconductor laser of the invention includes a (100) GaAs substrate having at least one stripe groove formed on an upper face thereof, and a semiconductor multilayer structure formed on the substrate. The stripe groove extends along a <1-10> direction. The semiconductor multilayer structure includes an Al.sub.x Ga.sub.1-x As layer (0.ltoreq.x.ltoreq.1) including a portion having a surface of an (all) crystal plane (a>1), the portion being positioned on the stripe groove, a pair of AlGaInP cladding layers provided on the Al.sub.x Ga.sub.1-x As layer (0.ltoreq.x.ltoreq.1), and an active layer sandwiched between the pair of AlGaInP cladding layers.

Abstract: A semiconductor laser of the invention includes a (100) GaAs substrate having at least one stripe groove formed on an upper face thereof, and a semiconductor multilayer structure formed on the substrate. The stripe groove extends along a <1-10> direction. The semiconductor multilayer structure includes an Al.sub.x Ga.sub.1-x As layer (0.ltoreq.x.ltoreq.1) including a portion having a surface of an (a11) crystal plane (a>1), the portion being positioned on the stripe groove, a pair of AlGaInP cladding layers provided on the Al.sub.x Ga.sub.1-x As layer (0.ltoreq.x.ltoreq.1), and an active layer sandwiched between the pair of AlGaInP cladding layers.

Abstract: A semiconductor laser according to the present invention includes: a semiconductor substrate; a multilayer structure provided on the semiconductor substrate, the multilayer structure including an active layer, a pair of cladding layers interposing the active layer, and current confining portion for injecting a current into a stripe-shaped predetermined region of the active layer, wherein the current confining portion includes a first current confining layer formed in regions excluding a region corresponding to the predetermined region of the active layer, the first current confining layer having an energy band gap larger than an energy band gap of the active layer and having a refractive index smaller than a refractive index of the active layer.