Abstract: An n-type GaN layer is grown onto a sapphire substrate and a hexagonal etching mask is formed onto the n-type GaN layer as provided. The n-type GaN layer is etched to a predetermined depth by using the etching mask by the RIE method. A hexagonal prism portion whose upper surface is a C plane is formed. After the etching mask was removed, an active layer and a p-type GaN layer are sequentially grown onto the whole surface of the substrate so as to cover the hexagonal prism portion, thereby forming a light emitting device structure. After that, a p-side electrode is formed onto the p-type GaN layer of the hexagonal prism portion and an n-side electrode is formed onto the n-type GaN layer.

Abstract: In a semiconductor light emitting device configured to extract light through a substrate thereof, an electrode layer is formed on a p-type semiconductor layer (such as p-type GaN layer) formed on an active layer, and a nickel layer is formed as a contact metal layer between the electrode layer and the p-type semiconductor layer and adjusted in thickness not to exceed the intrusion length of light generated in the active layer. Since the nickel layer is sufficiently thin, reflection efficiency can be enhanced.

Abstract: Semiconductor light emitting devices and methods of producing same are provided. The semiconductor light emitting devices include a substrate that has a surface including a difference-in-height portion composed of, for example, a wurtzite compound. A crystal growth layer is formed in the substrate surface wherein at least a portion of which is oriented along an inclined plane with respect to a principal plane of the substrate. The semiconductor device includes a first conductive layer, an active layer and a second conductive layer formed on the crystal layer in a stacked arrangement and oriented along the inclined place.

Abstract: Nitride semiconductor devices and methods of producing same are provided. The present invention includes forming a nitride semiconductor layer on a base body of the nitride semiconductor under selective and controlled crystal growth conditions. For example, the crystal growth rate, the supply of crystal growth source material and/or the crystal growth area can be varied over time, thus resulting in a nitride semiconductor device with enhanced properties.

Abstract: Nitride semiconductor devices and methods of producing same are provided. The present invention includes forming a nitride semiconductor layer on a base body of the nitride semiconductor under selective and controlled crystal growth conditions. For example, the crystal growth rate, the supply of crystal growth source material and/or the crystal growth area can be varied over time, thus resulting in a nitride semiconductor device with enhanced properties.

Abstract: Nitride semiconductor devices and methods of fabricating same are provided. The nitride semiconductor device includes a crystal layer grown into a three-dimensional shape having a side surface portion and an upper layer portion, wherein an electrode layer is formed on the upper layer portion via a high resistance region formed by an undoped gallium nitride layer or the like. Since the high resistance region is provided on the upper layer portion, a current flows so as to bypass the high resistance region of the upper layer portion, to form a current path extending mainly or substantially along the side surface portion while avoiding the upper layer portion, thereby suppressing the flow of a current in the upper layer portion poor in crystallinity.

Abstract: A first conductive type layer having a band gap energy smaller than that of an under growth layer formed on a substrate is formed by selective growth from an opening portion formed in the under growth layer, and an active layer and a second conductive type layer are stacked on the first conductive type layer, to form a stacked structure. When such a stacked structure for forming a semiconductor device is irradiated with laser beams having an energy value between the band gap energies of the under growth layer and the first conductive type layer, abrasion occurs at a first conductive type layer side interface between the under growth layer and the first conductive type layer, so that the stacked structure is peeled from the substrate and the under growth layer and simultaneously isolated from another stacked structure for forming another semiconductor device.

Abstract: A semiconductor light emitting device with improved luminous efficiency is provided. An underlying n-type GaN layer is grown on a sapphire substrate, and a growth mask made from SiO2 film or the like is formed on the underlying n-type GaN layer. An n-type GaN layer having a hexagonal pyramid shape is selectively grown on a portion, exposed from an opening of the growth mask, of the underlying n-type GaN layer. The growth mask is removed by etching, and then an active layer and a p-type GaN layer are sequentially grown on the entire substrate so as to cover the hexagonal pyramid shaped n-type GaN layer, to form a light emitting device. An n-side electrode and a p-side electrode are then formed.

Abstract: Semiconductor light emitting devices and a method of fabricating the semiconductor light emitting devices are provided. The semiconductor light emitting device includes a growth substrate, a first growth layer formed on the growth substrate, a growth obstruction film formed on the first growth layer, and a second growth layer formed by selective growth from an opening portion formed in the growth obstruction film, wherein device isolation trenches for isolating devices from each other are formed in the first growth layer formed on the growth substrate, and the second growth layer is formed by selective growth after formation of the device isolation trenches.

Abstract: A crystal foundation having dislocations is used to obtain a crystal film of low dislocation density, a crystal substrate, and a semiconductor device. One side of a growth substrate (11) is provided with a crystal layer (13) with a buffer layer (12) in between. The crystal layer (13) has spaces (13a), (13b) in an end of each threading dislocation D1 elongating from below. The threading dislocation D1 is separated from the upper layer by the spaces (13a), (13b), so that each threading dislocation D1 is blocked from propagating to the upper layer. When the displacement of the threading dislocation D1 expressed by Burgers vector is preserved to develop another dislocation, the spaces (13a), (13b) vary the direction of its displacement. As a result, the upper layer above the spaces (13a), (13b) turns crystalline with a low dislocation density.

Abstract: Disclosed are a nitride semiconductor device excellent in characteristics, which has a device structure grown into a three-dimensional shape by selective growth, and a method of fabricating the nitride semiconductor device. The nitride semiconductor device according to the present invention includes a crystal layer grown into a three-dimensional shape having a side surface portion (16s) and an upper layer portion (16t), wherein and electrode layer (21) is formed on the upper layer portion via a high resistance region formed by an undoped gallium nitride layer (17) or the like. Since the high resistance region is provided on the upper layer portion (16t), a current flows so as to bypass the high resistance region of the upper layer portion (16t), to form a current path extending mainly along the side surface portion (16s) while avoiding the upper layer portion (16t), thereby suppressing the flow of a current in the upper layer portion (16t) poor in crystallinity.

Abstract: In a semiconductor light emitting device configured to extract light through a substrate thereof, an electrode layer is formed on a p-type semiconductor layer (such as p-type GaN layer) formed on an active layer, and a nickel layer is formed as a contact metal layer between the electrode layer and the p-type semiconductor layer and adjusted in thickness not to exceed the intrusion length of light generated in the active layer. Since the nickel layer is sufficiently thin, reflection efficiency can be enhanced.

Abstract: A semiconductor light emitting device includes a crystal layer formed on a substrate, the crystal layer having a tilt crystal plane tilted from the principal plane of the substrate, and a first conductive type layer, an active layer, and a second conductive type layer, which are formed on the crystal layer in such a manner as to extend within planes parallel to the tilt crystal plane, wherein the device has a shape formed by removing the apex and its vicinity of the stacked layer structure formed on the substrate. Such a semiconductor light emitting device is excellent in luminous efficiency even if the device has a three-dimensional device structure. The present invention also provides a method of fabricating the above semiconductor light emitting device.

Abstract: A crystal growth method includes forming a mask layer capable of impeding crystal growth on a substrate in such a way a first nitride semiconductor layer has irregularities at a surface thereof exposed at a window region opened at a part of the mask layer, and growing a second nitride semiconductor layer over a region including the surface of the mask layer through crystal growth from the irregularities. Through-type dislocations can be reliably prevented from propagation due to the discontinuity of crystals at the irregularities and also to lateral crystal growth.

Abstract: A semiconductor light emitting device including an active layer formed on a tilt crystal is provided. The device generates induced emission light by optical pumping, and has an excellent luminous efficiency. The active layer has a multi-quantum well structure including, for example, an InGaN layer as a quantum well. The contents of In and Ga in the InGaN layer satisfy a relation of In/(In+Ga)≧0.9. The device is equivalent to a super luminescent diode, and if having a resonance structure, it becomes a laser diode. In particular, a pyramid type laser diode can be also realized.

Abstract: In a selective growth method, growth interruption is performed at the time of selective growth of a crystal layer on a substrate. Even if the thickness distribution of the crystal layer becomes non-uniform at the time of growth of the crystal layer, the non-uniformity of the thickness distribution of the crystal layer can be corrected by inserting the growth interruption. As a result of growth interruption, an etching rate at a thick portion becomes higher than that at a thin portion, to eliminate the difference in thickness between the thick portion and the thin portion, thereby solving the problem associated with degradation of characteristics due to a variation in thickness of the crystal layer, for example, an active layer. The selective growth method is applied to fabrication of a semiconductor light emitting device including an active layer as a crystal layer formed on a crystal layer having a three-dimensional shape by selective growth.

Abstract: A semiconductor light emitting device is fabricated by forming a mask having an opening on a substrate, forming a crystal layer having a tilt crystal plane tilted from the principal plane of the substrate by selective growth from the opening of the mask, and forming, on the crystal layer, a first conductive type layer, an active layer, and a second conductive type layer, which extend within planes parallel to the tilt crystal plane, and removing the mask. The semiconductor light emitting device can be fabricated without increasing fabrication steps while suppressing threading dislocations extending from the substrate side and keeping a desirable crystallinity. The semiconductor light emitting device is also advantageous in that since deposition of polycrystal on the mask is eliminated, an electrode can be easily formed, and that the device structure can be finely cut into chips.

Abstract: At the time of selective growth of an active layer on a substrate, crystal is previously grown in an active layer non-growth region, and the active layer is grown in an active layer selective growth region. With this configuration, a source supplied to the non-growth region is incorporated in the deposited crystal from the initial stage of growth, so that the supplied amount of the source to the active layer selective growth region is kept nearly at a constant value over the entire period of growth of the active layer, to eliminate degradation of characteristics of the device due to a variation in growth rate of the active layer. In particular, the selective growth method is effective in fabrication of a semiconductor light emitting device including a cladding layer, a guide layer, and an active layer, each of which is formed by selective growth, wherein the active layer has multiple quantum wells.

Abstract: A semiconductor light-emitting element having a structure that does not complicate a fabrication process, can be formed in high precision and does not invite any degradation of crystallinity is provided. A light-emitting element is formed, which includes a selective crystal growth layer formed by selectively growing a compound semiconductor of a Wurtzite type, and a clad layer of a first conduction type, an active layer and a clad layer of a second conduction type, which are formed on the selective crystal growth layer wherein the active layer is formed so that the active layer extends in parallel to different crystal planes, the active layer is larger in size than a diffusion length of a constituent atom of a mixed crystal, or the active layer has a difference in at least one of a composition and a thickness thereof, thereby forming the active layer having a plurality of light-emitting wavelength region whose emission wavelengths differ from one another.

Abstract: Disclosed herein is a process for vapor phase growth of gallium nitride compound semiconductor which yields uniform crystal layers with good reproducibility. The process comprises forming a first nitride semiconductor layer on a substrate, forming thereon a protective film for crystal growth prevention in such a way that it has partly open window regions through which the first nitride semiconductor layer is exposed, forming a second nitride semiconductor layer by selective growth from the first nitride semiconductor layer at a crystal growth starting temperature, and continuing crystal growth at a temperature higher than the crystal growth starting temperature. The vapor phase growth at a low temperature yields a uniform crystal layer, and the ensuing vapor phase growth at a raised temperature yields a uniform crystal layer with good reproducibility in conformity with the first crystal layer.