Abstract:
Electronic devices involving contact structures, and related components, systems and methods associated therewith are described. Contact structures (also referred to as electrical contact structures or electrodes) are features on a device that are electrically connected to a power source. The power source can provide current to the device via the contact structures. The contact structures can be designed to improve current distribution in electronic devices. For example, the contact resistance of the contacts may be modified to improve current distribution (e.g., by controlling the shape and/or structure and/or composition of the contacts). The contact structures may include an intervening layer (e.g., a non-ohmic layer) positioned between a surface of the device and a conductive portion extending from a conductive pad. The intervening layer and/or conductive portions may be designed to have certain shapes (e.g., non-linear shapes) that promote current flow from the conductive pad towards the ends of the contacts to increase current spreading. The intervening layer can also reduce light generation underneath the light absorbing contacts to allow a greater percentage of the generated light to emerge from the surface of the device. Advantageously, devices including contact structures of the invention can increase uniformity of light emission and/or otherwise improve performance. As such, these contact structures are particularly suitable for use in a variety of light-emitting devices, including LEDs.
Abstract:
A method of fabricating a semiconductor device includes the steps of forming (or providing) a series of layers formed on a substrate, the layers including a first plurality of layers including an n-type ohmic contact layer, a p-type modulation doped quantum well structure, an n-type modulation doped quantum well structure, and a fourth plurality of layers including a p-type ohmic contact layer. Etch stop layers are used during etching operations when forming contacts to the n-type ohmic contact layer and contacts to the n-type modulation doped quantum well. Preferably, each such etch stop layer is made sufficiently thin to permit current tunneling therethrough during operation of optoelectronic/electronic devices realized from this structure (including heterojunction thyristor devices, n-channel HFET devices, p-channel HFET devices, p-type quantum-well-base bipolar transistor devices, and n-type quantum-well-base bipolar transistor devices). The etch stop layer(s) preferably comprise AlAs that functions as an etch stop during etching by a chlorine-based gas mixture that includes fluorine. The series of layers preferably comprise group III-V materials.
Abstract:
A pneumatically actuated drain stopper system and apparatus which includes a source of compressed gas, a pressure regulator, a piston drain, a push-button or toggle switch interposed between the piston drain and the pressure regulator, and pneumatic lines connecting the piston drain to the switch and the switch to the gas source, and bringing all elements into fluid communication with one another.
Abstract:
A unitary removable barrier for installation in a cylindrical water line to selectively block the water line to passage of water therethrough. The unitary removable barrier is composed of a single piece rubber body having at least one cylindrical section sized to receive upstream and downstream pipes of the water line. A unitary rubber planar disc molded with the cylindrical section is of a circular circumference and which completely blocks the water line but which is selectively removable from the cylindrical section thus removing the barrier to the passage of the water through the line.
Abstract:
A unitary removable barrier for installation in a cylindrical water line to selectively block the water line to passage of water therethrough. The unitary removable barrier is composed of a single piece rubber body having at least one cylindrical section sized to receive upstream and downstream pipes of the water line. A unitary rubber planar disc molded with the cylindrical section is of a circular circumference and which completely blocks the water line but which is selectively removable from the cylindrical section thus removing the barrier to the passage of the waste through the line.
Abstract:
The present invention is directed to a one-step process for the preparation of fructopyranose sulfamate derivatives of the general formula (I) wherein X, R1, R3, R4, R5 and R6 are as described in the specification.
Abstract:
An optoelectronic integrated circuit comprises a substrate, a multilayer structure formed on the substrate, and an array of thyristor devices and corresponding resonant cavities formed in the multilayer structure. The resonant cavities, which are adapted to process different wavelengths of light, are formed by selectively removing portions of said multilayer structure to provide said resonant cavities with different vertical dimensions that correspond to the different wavelengths. Preferably, that portion of the multilayer structure that is selectively removed to provide the multiple wavelengths includes a periodic substructure formed by repeating pairs of an undoped spacer layer and an undoped etch stop layer. The multilayer structure may be formed from group III-V materials. In this case, the undoped spacer layer and undoped etch stop layer of the periodic substructure preferably comprises undoped GaAs and undoped AlAs, respectively. The undoped AlAs functions as an etch stop during etching by a chlorine-based gas mixture that includes fluorine. The array of multi-wavelength thyristor devices may be used to realize devices that provide a variety of optoelectronic functions, such as an array of thyristor-based lasers that emit light at different wavelengths and/or an array of thyristor-based detectors that detect light at different wavelengths (e.g., for wavelength-division-multiplexing applications).
Abstract:
A unitary removable barrier for installation in a cylindrical water line to selectively block the water line to passage of water therethrough. The unitary removable barrier is composed of a single piece body having at least one cylindrical section sized to receive upstream and downstream pipes of the water line. A planar disk is molded with the cylindrical section and is of a circular circumference which completely blocks the water line but which is selectively removable from the cylindrical section thus removing the barrier to the passage of water through the line. Removal of the barrier is facilitated through the use of a piercing device and pull tab which can be actuated from a position outside of the waste line.
Abstract:
A stopper device for selectively blocking a drain to the passage of water. The drain is provided with an inlet, an outlet and a substantially cylindrical throat between said inlet and outlet. A controllably expandable bladder is located within the cylindrical throat which is sized and positioned such that when the bladder is compressed, the drain is selectively blocked to the passage of water and when the bladder is extended, the drain is selectively opened to the passage of water.