Patent application number | Description | Published |
20090230381 | AlInGaP LED HAVING REDUCED TEMPERATURE DEPENDENCE - To increase the lattice constant of AlInGaP LED layers to greater than the lattice constant of GaAs for reduced temperature sensitivity, an engineered growth layer is formed over a substrate, where the growth layer has a lattice constant equal to or approximately equal to that of the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP layer is grown over a GaAs substrate. The amount of indium is increased during growth of the layer such that the final lattice constant is equal to that of the desired AlInGaP active layer. In another embodiment, a very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate, where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs and relaxed, causing the lattice constant of the thin layer to increase to the lattice constant of the desired overlying AlInGaP LED layers. The LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer. | 09-17-2009 |
20090261361 | III-NITRIDE LIGHT EMITTING DEVICE WITH DOUBLE HETEROSTRUCTURE LIGHT EMMITTING REGION - A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition. | 10-22-2009 |
20100032793 | METHODS FOR RELAXATION AND TRANSFER OF STRAINED LAYERS AND STRUCTURES FABRICATED THEREBY - The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer. | 02-11-2010 |
20100176490 | METHODS OF FORMING RELAXED LAYERS OF SEMICONDUCTOR MATERIALS, SEMICONDUCTOR STRUCTURES, DEVICES AND ENGINEERED SUBSTRATES INCLUDING SAME - Methods of fabricating relaxed layers of semiconductor materials include forming structures of a semiconductor material overlying a layer of a compliant material, and subsequently altering a viscosity of the compliant material to reduce strain within the semiconductor material. The compliant material may be reflowed during deposition of a second layer of semiconductor material. The compliant material may be selected so that, as the second layer of semiconductor material is deposited, a viscosity of the compliant material is altered imparting relaxation of the structures. In some embodiments, the layer of semiconductor material may comprise a III-V type semiconductor material, such as, for example, indium gallium nitride. Methods of fabricating semiconductor structures and devices are also disclosed. Novel intermediate structures are formed during such methods. Engineered substrates include a plurality of structures comprising a semiconductor material disposed on a layer of material exhibiting a changeable viscosity. | 07-15-2010 |
20100264454 | SEMICONDUCTOR LIGHT EMITTING DEVICE GROWING ACTIVE LAYER ON TEXTURED SURFACE - In accordance with embodiments of the invention, at least partial strain relief in a light emitting layer of a III-nitride light emitting device is provided by configuring the surface on which at least one layer of the device grows such that the layer expands laterally and thus at least partially relaxes. This layer is referred to as the strain-relieved layer. In some embodiments, the light emitting layer itself is the strain-relieved layer, meaning that the light emitting layer is grown on a surface that allows the light emitting layer to expand laterally to relieve strain. In some embodiments, a layer grown before the light emitting layer is the strain-relieved layer. In a first group of embodiments, the strain-relieved layer is grown on a textured surface. | 10-21-2010 |
20100327256 | CONTROLLING PIT FORMATION IN A III-NITRIDE DEVICE - A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region and a plurality of layer pairs disposed within one of the n-type region and the p-type region. Each layer pair includes an InGaN layer and pit-filling layer in direct contact with the InGaN layer. The pit-filling layer may fill in pits formed in the InGaN layer. | 12-30-2010 |
20110027975 | SUBSTRATE FOR GROWING A III-V LIGHT EMITTING DEVICE - A substrate including a host and a seed layer bonded to the host is provided, then a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is grown on the seed layer. In some embodiments, a bonding layer bonds the host to the seed layer. The seed layer may be thinner than a critical thickness for relaxation of strain in the semiconductor structure, such that strain in the semiconductor structure is relieved by dislocations formed in the seed layer, or by gliding between the seed layer and the bonding layer an interface between the two layers. In some embodiments, the host may be separated from the semiconductor structure and seed layer by etching away the bonding layer. | 02-03-2011 |
20110177631 | METHOD OF FORMING A COMPOSITE SUBSTRATE AND GROWING A III-V LIGHT EMITTING DEVICE OVER THE COMPOSITE SUBSTRATE - A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions. | 07-21-2011 |
20110180911 | METHODS FOR RELAXATION AND TRANSFER OF STRAINED LAYERS AND STRUCTURES FABRICATED THEREBY - The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer. | 07-28-2011 |
20110272720 | LIGHT EMITTING DEVICE GROWN ON WAVELENGTH CONVERTING SUBSTRATE - In some embodiments of the invention, a device includes a substrate and a semiconductor structure. The substrate includes a wavelength converting element comprising a wavelength converting material disposed in a transparent material, a seed layer comprising a material on which III-nitride material will nucleate, and a bonding layer disposed between the wavelength converting element and the seed layer. The semiconductor structure includes a III-nitride light emitting layer disposed between an n-type region and a p-type region, and is grown on the seed layer. | 11-10-2011 |
20120161187 | Grown Photonic Crystals in Semiconductor Light Emitting Devices - A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts. | 06-28-2012 |
20120205691 | Controlling Pit Formation in a III-Nitride Device - A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region and a plurality of layer pairs disposed within one of the n-type region and the p-type region. Each layer pair includes an InGaN layer and pit-filling layer in direct contact with the InGaN layer. The pit-filling layer may fill in pits formed in the InGaN layer. | 08-16-2012 |
20120214291 | RELAXATION OF STRAINED LAYERS - A method for relaxing a layer of a strained material. The method includes depositing a first low-viscosity layer on a first face of a strained material layer; bonding a first substrate to the first low-viscosity layer to form a first composite structure; subjecting the composite structure to heat treatment sufficient to cause reflow of the first low-viscosity layer so as to at least partly relax the strained material layer; and applying a mechanical pressure to a second face of the strained material layer wherein the second face is opposite to the first face and with the mechanical pressure applied perpendicularly to the strained material layer during at least part of the heat treatment to relax the strained material. | 08-23-2012 |