摘要:
Various asymmetric InGaAsN VCSEL structures that are made using an MOCVD process are presented. Use of the asymmetric structure effectively eliminates aluminum contamination of the quantum well active region.
摘要:
Methods for defect-free impurity-induced laser disordering (IILD) of AlGaInP and AlGaAs heterostructures. Phosphorus-doped or As-doped films are used in which silicon serves as a diffusion source and silicon nitride acts as a barrier for selective IILD. High-performance, index-guided (AlGa).sub.0.5 In.sub.0.5 P lasers may be fabricated with this technique, analogous to those made in the AlGaAs material system. The deposition of the diffusion source films preferably is carried out in a low pressure reactor. Also disclosed is a scheme for reducing or eliminating phosphorus overpressure during silicon diffusion into III-V semiconducting material by adding a pre-diffusion anneal step. Defects produced during intermixing are also reduced using a GaInP or GaInP/GaAs cap.
摘要:
A QW diode laser generating orthogonally polarized multiple beams. The device incorporates quantum well active regions capable of, transitions to heavy hole and light hole band edges. The heavy hole transition provides TE-mode gain, while the light hole band provides mostly TM-mode gain. By controlling the compositions and thicknesses of the active regions, both modes can be obtained in a monolithic structure. In addition, the resulting laser polarization will be very sensitive to the threshold carrier density. With an intracavity loss modulator in such a structure, the polarization can also be controlled. Other ways of causing side-by-side lasers to operate, respectively, in their TE or TM modes are also described.
摘要:
Ridged waveguide and selectively-buried ridged waveguide, index-guided, visible semiconductor lasers incorporating a lattice-mismatched, preferably tensile-strained, etch-stop layer in the design and fabrication of the laser. Compared with other structures with etch-stop layers that are lattice matched, the etch-stop layer of the invention would have greater etch-rate selectivity, and the resulting structure would be more optically transparent with less transverse mode distortion and would present fewer difficulties with layer regrowth. These advantages would translate into greater design flexibility, more reliable fabrication, and better device performance. A preferred material for the etch-stop layer is Ga.sub.x In.sub.1-x P (x>0.5).
摘要:
A semiconductor device includes a III-nitride substrate having a first conductivity type and a first electrode electrically coupled to the III-nitride substrate. The semiconductor device also includes a III-nitride material having a second conductivity type coupled to the III-nitride substrate at a regrowth interface and a p-n junction disposed between the III-nitride substrate and the regrowth interface.
摘要:
A vertical JFET includes a III-nitride substrate and a III-nitride epitaxial layer of a first conductivity type coupled to the III-nitride substrate. The first III-nitride epitaxial layer has a first dopant concentration. The vertical JFET also includes a III-nitride epitaxial structure coupled to the first III-nitride epitaxial layer. The III-nitride epitaxial structure includes a set of channels of the first conductivity type and having a second dopant concentration, a set of sources of the first conductivity type, having a third dopant concentration greater than the first dopant concentration, and each characterized by a contact surface, and a set of regrown gates interspersed between the set of channels. An upper surface of the set of regrown gates is substantially coplanar with the contact surfaces of the set of sources.
摘要:
An MPS diode includes a III-nitride substrate characterized by a first conductivity type and a first dopant concentration and having a first side and a second side. The MPS diode also includes a III-nitride epitaxial structure comprising a first III-nitride epitaxial layer coupled to the first side of the substrate, wherein a region of the first III-nitride epitaxial layer comprises an array of protrusions. The III-nitride epitaxial structure also includes a plurality of III-nitride regions of a second conductivity type, each partially disposed between adjacent protrusions. Each of the plurality of III-nitride regions of the second conductivity type comprises a first section laterally positioned between adjacent protrusions and a second section extending in a direction normal to the first side of the substrate. The MPS diode further includes a first metallic structure electrically coupled to one or more of the protrusions and to one or more of the second sections.
摘要:
A semiconductor structure includes a III-nitride substrate with a first side and a second side opposing the first side. The III-nitride substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a III-nitride epitaxial structure including a first III-nitride epitaxial layer coupled to the first side of the III-nitride substrate and a plurality of III-nitride regions of a second conductivity type. The plurality of III-nitride regions have at least one III-nitride epitaxial region of the first conductivity type between each of the plurality of III-nitride regions. The semiconductor structure further includes a first metallic structure electrically coupled to one or more of the plurality of III-nitride regions and the at least one III-nitride epitaxial region. A Schottky contact is created between the first metallic structure and the at least one III-nitride epitaxial region.
摘要:
An MPS diode includes a III-nitride substrate characterized by a first conductivity type and a first dopant concentration and having a first side and a second side. The MPS diode also includes a III-nitride epitaxial structure comprising a first III-nitride epitaxial layer coupled to the first side of the substrate, wherein a region of the first III-nitride epitaxial layer comprises an array of protrusions. The III-nitride epitaxial structure also includes a plurality of III-nitride regions of a second conductivity type, each partially disposed between adjacent protrusions. Each of the plurality of III-nitride regions of the second conductivity type comprises a first section laterally positioned between adjacent protrusions and a second section extending in a direction normal to the first side of the substrate. The MPS diode further includes a first metallic structure electrically coupled to one or more of the protrusions and to one or more of the second sections.
摘要:
A method for fabricating a III-nitride semiconductor device includes providing a III-nitride substrate having a first surface and a second surface opposing the first surface, forming a III-nitride epitaxial layer coupled to the first surface of the III-nitride substrate, and removing at least a portion of the III-nitride epitaxial layer to form a first exposed surface. The method further includes forming a dielectric layer coupled to the first exposed surface, removing at least a portion of the dielectric layer, and forming a metallic layer coupled to a remaining portion of the dielectric layer such that the remaining portion of the dielectric layer is disposed between the III-nitride epitaxial layer and the metallic layer.