Distributed Bragg Reflectors (DBRs) are a fundamental component of optical devices requiring an optical gain, such as various types of semiconductor lasers....
Distributed Bragg Reflectors (DBRs) are a fundamental component of optical devices requiring an optical gain, such as various types of semiconductor lasers. Conventional methods of forming DBRs require high numbers of layers of semiconductor materials to get the desired reflective resolution. This new method of forming DBRs controls the microstructure of the layers and offers improved vertical cavity surface emitting lasers (VCSELs) and resonant cavity light emitting diodes (LEDs).
This technology is a method for making a highly reflective interface for distributed Bragg reflectors (DBRs), which are used in VCSELs and resonant cavity LEDs to generate optical activity. Using Group III-V materials, the interface consists of amorphous layers that contain aluminum, which when oxidized significantly increases the refractive index. As a result, the number of layers needed for the DBR can be reduced from about 30 to 4 or 5. A key element of this technology is that by using a combination of alternating polycrystalline and amorphous materials the layers can be applied to any surface, regardless of the substrate's lattice constant. Therefore, the DBR can be created on any substrate, including glass and silicon, and has a wider range of design possibilities. Additionally, changing the thickness of the layers allows reflectors of different wavelengths to be created. Highly reflective DBRs which reflect in the short wavelength of the visible spectrum and deep into the ultraviolet wavelength can be formed by this method. This technology has been tested extensively with the most common material sets, gallium arsenide (GaAs) and gallium phosphide (GaP) systems.
A polymer comprises at least two types of monomer units selected from: (1) diethynyl benzene units, (2) triethynyl benzene units, and (3) ester units. After curing...
A polymer comprises at least two types of monomer units selected from: (1) diethynyl benzene units, (2) triethynyl benzene units, and (3) ester units. After curing, the polymer may form a condensed polyaromatic dielectric having a dielectric constant of at most 2.0 at 1 MHz, an elastic modulus of at least 7.7 GPa, and a hardness of at least 2.0 GPa.
An innovative, cost-effective method for making and integrating fluidic microchannels. This method for ultra-rapid prototyping of microfluidic systems requiring...
An innovative, cost-effective method for making and integrating fluidic microchannels. This method for ultra-rapid prototyping of microfluidic systems requiring fewer than 5 minutes from design to prototype uses liquid phase polymerization as an alternative to etching microchannels in silcone or glass.
The method consists of introducing liquid prepolymer into a plastic or glass cartridge, exposing the prepolymer to ultraviolet light through a mask to encourage photopolymerization and define channel geometry, removing the unpolymerized prepolymer, and rinsing the resulting microchannel.
The actuators used in this technology require nothing more than the chemicals surrounding them to monitor the chemistry, mimicking chemical balances as they are maintained in the human body. This new method is ideal for biological and medical applications requiring organic materials, no electronics or batteries, bioresponsiveness, and a single, uniform platform for processing. Potential applications include detection of biological and chemical agents, disease, and contaminants, and in vitro diagnostics and therapy devices. Other promising applications exist in the area of microelectromechanical systems (MEMS).
The invention greatly reduces the time and cost associated with the creation of microfluidics systems and requires no experience in microfabrication techniques, no cleanroom facilities, and no expensive equipment. Easy integration enables a manufacturing environment to readily incorporate "add-on" fluidics. This new technology allows ultra rapid prototyping and iterative design, affords immediate production of components, and simplifies complex systems
The invention is a novel method for manufacturing porous semiconductors, including silicon (Si), gallium nitride (GaN) and silicon carbide (SiC). The method...
The invention is a novel method for manufacturing porous semiconductors, including silicon (Si), gallium nitride (GaN) and silicon carbide (SiC). The method involves applying a thin, discontinuous metallic (preferably platinum) layer to a semiconductor wafer, prior to using common wet chemical etchants (e.g., hydrogen fluoride, hydrogen peroxide), to produce porous silicon (PSi) or other porous semiconductors (PGaN, PSiC).
Porous semiconductors are of interest for their novel optical, electronic, and chemical properties, with PSi being of particular interest. This technology applies a thin, discontinuous layer of metal to a semiconductor wafer before using a wet chemical etching process to produce a controlled thickness of porous semiconductor. The process can be adjusted to produce specific morphologies and desired light emission spectral and/or spatial distributions.
This technology introduces a thin, metal catalyst film (a few nanometers in thickness) onto the semiconductor wafer surface, prior to immersion in an aqueous, oxidizing solution of hydrofluoric acid and hydrogen peroxide (i.e., H2O2 metal-HF etching). This process results in the simple and effective production of porous semiconductor. The simplicity and patterning capability will enable large-scale production. PSi with various morphologies, etch depths, and luminescent properties can be produced by adjusting the type(s) of metal layer deposited (gold, platinum, or gold/palladium) as well as the dopant type and level (p+, p-, or n+) of the silicon.
Current methods for generating PSi use anodic etching. In anodic etching, a silicon wafer with attached electrodes and leads is submerged in a wet chemical bath and an electrical bias is applied to drive the etching process. While PSi is not commonly used today in optical or electrical devices, anodic etching is used routinely to generate PSi used to fabricate silicon-on-insulator (SOI) wafers for the electronics industry. A drawback of anodic etching is the extra infrastructure and complexity of applying an electrical bias to a thin wafer submerged in an etchant. At a minimum, it requires electrodes, leads, a power supply, and control electronics.
This new technology is an elegantly simple alternative to anodic etching. It is an electroless technique, i.e., external electrical bias is not required, that circumvents all electrical accessories and associated methods. This novel process is also robust, controllable, and even allows flexibility for generating PSi in selected areas rather than across the entire wafer. In addition, this technology provides up to an order of magnitude enhancement in the luminescent properties of PSi compared to those of material produced using anodic etching. Furthermore, researchers may find applications for PSi that would never be possible using anodic etching.
Amorphous and polycrystalline III-V semiconductor including (Ga,As), (Al,As), (In,As), (Ga,N), and (Ga,P) materials were grown at low temperatures on semiconductor...
Amorphous and polycrystalline III-V semiconductor including (Ga,As), (Al,As), (In,As), (Ga,N), and (Ga,P) materials were grown at low temperatures on semiconductor substrates. After growth, different substrates containing the low temperature grown material were pressed together in a pressure jig before being annealed. The annealing temperatures ranged from about 300.degree. C. to 800.degree. C. for annealing times between 30 minutes and 10 hours, depending on the bonding materials. The structures remained pressed together throughout the course of the annealing. Strong bonds were obtained for bonding layers between different substrates that were as thin as 3 nm and as thick as 600 nm. The bonds were ohmic with a relatively small resistance, optically transparent, and independent of the orientation of the underlying structures.
A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide...
A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide guides emission. The waveguide includes a broad area straight coupling region that fans out into an array of narrower Individual curved coupled waveguides at an output facet of the laser. The individual curved coupled waveguides are curved according to Lorentzian functions that define the waveguide curvature as a function of position along the device.
The integral length of each individual curved coupled waveguide differs from adjacent individual curved coupled waveguides by an odd number of half-wavelengths. The coupled waveguide array shapes the optical field output of the semiconductor laser such that a large fraction of the power is emitted into a small angular distribution using interference phenomena. A laser of the invention produces high power output with a very high quality, narrow beam shape.
A method for producing light emission, including the following steps: providing a transistor structure that includes a semiconductor base region disposed between a...
A method for producing light emission, including the following steps: providing a transistor structure that includes a semiconductor base region disposed between a semiconductor emitter region and a semiconductor collector region; providing a cascade region between the base region and the collector region, the cascade region having a plurality of sequences of quantum size regions, the quantum size regions of the sequences varying, in the direction toward the collector region, from a relatively higher energy state to a relatively lower energy state; providing emitter, base and collector electrodes respectively coupled with the emitter, base, and collector regions; and applying electrical signals with respect to the emitter, base, and collector electrodes to cause and control light emission from the cascade region.
Electrochemical fabrication platforms for making structures, arrays of structures and functional devices having selected nanosized and/or microsized physical...
Electrochemical fabrication platforms for making structures, arrays of structures and functional devices having selected nanosized and/or microsized physical dimensions, shapes and spatial orientations. Methods, systems and system components use an electrochemical stamping tool such as solid state polymeric electrolytes for generating patterns of relief and/or recessed features exhibiting excellent reproducibility, pattern fidelity and resolution on surfaces of solid state ionic conductors and in metal. Electrochemical stamping tools are capable high throughput patterning of large substrate areas, are compatible with commercially attractive manufacturing pathways to access a range of functional systems and devices including nano- and micro-electromechanical systems, sensors, energy storage devices, metal masks for printing, interconnects, and integrated electronic circuits.