129 results about "Tunnel diode" patented technology

The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like.

A SRAM cell includes a single FinFET and two resonant tunnel diodes. The FinFet has multiple channel regions formed from separate fins. The resonant tunnel diodes may be formed from FinFET type fins. In particular, the resonant diodes may includes a thin, undoped silicon region surrounded by a dielectric. The SRAM cell is small and provides fast read/write access times.

A highly sensitive, high-speed dual tunnel diode detector is described for use in Ultra Wideband (UWB) object detection systems, such as a radar. The extended capability of the detector to both extremely short (sub-foot) and long distance (tens of thousands of feet) ranges is unique and permits the application of low power UWB radar to a wide variety of applications including high resolution radar altimetry at altitudes exceeding 10,000 feet and for autonomous on-deck landing operations (e.g., one-foot altitudes), the detection of extremely low radar cross section (RCS) targets for such applications as suspended wire detection for helicopters and other manned and unmanned craft, etc. High noise and interference immunity of the detector permits co-location of a UWB radar sensor with other active systems. The invention has immediate and significant application to all areas, both military and commercial, of precision distance measurement, intrusion detection, targeting, etc. over a wide range of distances.

Three configurations of double barrier resonant tunneling diodes (RTD) are provided along with methods of their fabrication. The tunneling barrier layers of the diode are formed of low band offset dielectric materials and produce a diode with good I-V characteristics including negative differential resistance (NDR) with good peak-to-valley ratios (PVR). Fabrication methods of the RTD start with silicon-on-insulator substrates (SOI), producing silicon quantum wells, and are, therefore, compatible with main stream CMOS technologies such as those applied to SOI double gate transistor fabrication. Alternatively, Ge-on-insulator or SiGe-on-insulator substrates can be used if the quantum well is to be formed of Ge or SiGe. The fabrication methods include the formation of both vertical and horizontal silicon quantum well layers. The vertically formed layer may be oriented so that its vertical sides are in any preferred crystallographic plane, such as the 100 or 110 planes.

A nonmagnetic semiconductor device which may be utilized as a spin resonant tunnel diode (spin RTD) and spin transistor, in which low applied voltages and/or magnetic fields are used to control the characteristics of spin-polarized current flow. The nonmagnetic semiconductor device exploits the properties of bulk inversion asymmetry (BIA) in (110)-oriented quantum wells. The nonmagnetic semiconductor device may also be used as a nonmagnetic semiconductor spin valve and a magnetic field sensor. The spin transistor and spin valve may be applied to low-power and/or high-density and/or high-speed logic technologies. The magnetic field sensor may be applied to high-speed hard disk read heads. The spin RTD of the present invention would be useful for a plurality of semiconductor spintronic devices for spin injection and/or spin detection.

A tunable metamaterial has a two dimensional array of resonant annular ring elements; and a plurality of voltage controllable electrical tuning elements disposed in or adjacent openings in each of said ring elements, each of said voltage controllable electrical tuning element ohmically contacting portions of only one of said ring elements. The voltage controllable electrical tuning elements may comprise highly doped semiconductor tunnel diodes, or the charge accumulation layer at the semiconductor/insulator interface of a metal-insulator-semiconductor structure, or nanoelectromechanical (NEMs) capacitors. The tunable metamaterial may be used, for example, in an optical beam steering device using the aforementioned tunable optical metamaterial in which a free-space optical beam is coupled into a receiving portion of a plane of the optical metamaterial and is steered out of a transmitter portion of the plane of the optical metamaterial in controllable azimuthal and elevational directions. The tunable metamaterial additionally has other applications.

An antenna device is provided with a first connecting electrode, a first tunnel diode, a first antenna member and a fixed electrode. The first connecting electrode is configured to be connected to a fixed potential via a load. The first tunnel diode has a pair of electrodes. One of the electrodes of the first tunnel diode is connected to the first connecting electrode, and the other electrode of the first tunnel diode is connected to the first antenna member. The first antenna member has a conductive property and includes a first portion and a second portion. The first portion of the first antenna member is connected to the other electrode of the first tunnel diode. The fixed electrode is connected to the second portion of the first antenna member. The fixed electrode is configured to be connected to the fixed potential.

Adjacent pixels of an infrared focal plane array (IR FPA) can be configured to have different spectral or polarization responses by adjustment of the lengths or orientations of the antenna arms which couple radiation into the sensors. The manufacturing costs of such an antenna-coupled IR FPA would be much less than integration of spectral or polarization filters onto each pixel, or fabrication of adjacent pixels with materials of different bandgaps. The antenna-coupled pixels can be made smaller than usual pixels, allowing this diversity of spectral or polarization information on the FPA without losing spatial resolution. The infrared (IR) sensors can be tunnel diodes, schottky diodes, photovoltaics, photoconductors, bolometers, and pyroelectrics. Application areas can include military and civilian remote sensing, automotive driving aids, industrial sensing, medical imaging, and general surveillance.

An improved design for maintaining separation between electrodes in tunneling, diode, thermionic, and other devices is disclosed. At least one electrode is made from flexible material. A magnetic field is present to combine with the current flowing in the flexible electrode and generate a force that counterbalances the electrostatic force between the electrodes. The balancing of forces allows the separation and parallelism between the electrodes to be maintained at a very small spacing without requiring the use of multiple control systems, actuators, or other manipulating means, or spacers. The shape of one or both electrodes is designed to maintain a constant separation over the entire overlapping area of the electrodes. The end result is an electronic device that maintains two closely spaced parallel electrodes in stable equilibrium with a uniform gap therebetween over a large area in a simple configuration for simplified manufacturability and use to convert heat to electricity or electricity to cooling.

New Group III based diodes are disclosed having a low on state voltage (V_f), and structures to keep reverse current (I_rev) relatively low. One embodiment of the invention is Schottky barrier diode made from the GaN material system in which the Fermi level (or surface potential) of is not pinned. The barrier potential at the metal-to-semiconductor junction varies depending on the type of metal used and using particular metals lowers the diode's Schottky barrier potential and results in a V_f in the range of 0.1-0.3V. In another embodiment a trench structure is formed on the Schottky diodes semiconductor material to reduce reverse leakage current. and comprises a number of parallel, equally spaced trenches with mesa regions between adjacent trenches. A third embodiment of the invention provides a GaN tunnel diode with a low V_f resulting from the tunneling of electrons through the barrier potential, instead of over it. This embodiment can also have a trench structure to reduce reverse leakage current.

A microstrip stabilized quantum well resonance-tunneling generator which generates electromagnetic waves for millimeter and submillimeter wavelength range is provided The generator includes a resonant tunneling semiconductor quantum well diode, and a microstrip resonator. The resonant tunneling diode, the microstrip resonator and interconnecting lines and junctions are fabricated as a monolithic integrated device on a common substrate. As a result, the monolithic integrated device provides the expansion of the operation frequency range toward the terahertz region as a result of reduction of the parasitic inductance as well as of minimizing the other parasitic parameters of the electric circuitry connecting the resonant tunneling diode and resonator.

The present invention discloses a tunneling diode having a band gap material as the collector. This increases the tunneling of electrons having greater energy than the Fermi level from emitter to collector, leading to an increase in the efficiency of heat pumping or power generation by the diode. In a further embodiment the collector comprises a semiconductor on which a layer of band gap material is deposited. This approach also reduces back tunneling of electrons from collector to emitter.

A photodetector, detector array, and method of operation thereof in which nanojunctions are formed by crossing layers of nanowires. The crossing nanowires are separated by a few nm thick electrical barrier layer which allows tunneling. Each nanojunction is coupled to a slot antenna for efficient and frequency-selective coupling to photo signals. The nanojunctions formed at the intersection of the crossing wires defines a vertical tunneling diode that rectifies the AC signal from a coupled antenna and generates a DC signal suitable for reforming a video image. The nanojunction sensor allows multi/hyper spectral imaging of radiation within a spectral band ranging from terahertz to visible light, and including infrared (IR) radiation. This new detection approach also offers unprecedented speed, sensitivity and fidelity at room temperature.

The invention provides a tin-germanium-arsenic alloy material, a method for preparing the same and application thereof. The alloy material consists of the following components in weight percentage: 0.05 to 5 percent of Ge, 1 to 10 percent of As, and the balance being Sn. The preparation method comprises the following steps: in the range of the weight percentage, the high-purity tin, germanium and arsenic materials are weighed up; according to the order of arsenic, germanium and tin, the materials are placed in a quartz crucible, and the quartz crucible is placed in a high pressure reaction kettle; the reaction kettle is pumped vacuum and filled with argon, and the temperature and pressure of the reaction kettle are controlled to melt the tin and the germanium and make arsenic vapor enter the inner part of the tin-germanium melt mass to form an intermediate alloy; the intermediate alloy is cooled down to obtain tin-germanium-arsenic intermediate alloy ingot; and according to the weight percentage, the obtained intermediate alloy ingot and the remained tin and germanium are melted together and cast to obtain the tin-germanium-arsenic alloy material. The tin-germanium-arsenic alloy material is the basic alloy material for preparing high-quality tunnel diode, in which the tin-germanium-arsenic alloy material plays a role of an electrode electrodes, transforms P<+> to N<+> to form N<+>P<+> and a narrow space charge area and can be used to prepare vaporization plating materials as well as sputtering target materials.

A silicon-based interband tunneling diode (10, 110) includes a degenerate p-type doping (22, 130) of acceptors, a degenerate n-type doping (32, 118) of donors disposed on a first side of the degenerate p-type doping (22, 130), and a barrier silicon-germanium layer (20, 136) disposed on a second side of the degenerate p-type doping (22, 130) opposite the first side. The barrier silicon-germanium layer (20, 136) suppresses diffusion of acceptors away from a p/n junction defined by the degenerate p-type and n-type dopings (22, 32, 118, 130).

A photovoltaic cell comprising a thin semiconductor lamina is described; the lamina is formed by cleaving from a donor wafer while the wafer is bonded to a receiver element which provides mechanical support. Thus fabrication steps performed following cleaving are advantageously performed at temperatures that will not damage the receiver element. By fabricating a cell comprising an MIS-type tunnel diode, rather than a conventional p-n diode, a high-temperature doping step may be avoided.

Interband tunnel diodes which are compatible with Si-based processes such as, but not limited to, CMOS and SiGe HBT fabrication. Interband tunnel diodes are disclosed (i) with spacer layers surrounding a tunnel barrier; (ii) with a quantum well adjacent to, but not necessarily in contact with, one of the injectors, and (iii) with a first quantum well adjacent to, but not necessarily in contact with, the bottom injector and a second quantum well adjacent to, but not necessarily in contact with, the top injector. Process parameters include temperature process for growth, deposition or conversion of the tunnel diode and subsequent thermal cycling which to improve device benchmarks such as peak current density and the peak-to-valley current ratio.

A high-speed optical modulator based on Surface Plasmon-Polariton (SPP) at the hetero-junction of a metal-insulator-semiconductor (MIS) tunneling diode and including a phase-matching optical element, such as a prism or gold-lattice structure, is described. An investigation using the coupled mode theory shows that the applied bias across the hetero-junction changes the optical reflectance of an optically coupled MIS tunneling diode, such as a prism-coupled MIS tunneling diode or a gold lattice-coupled MIS tunneling diode, while the modulation efficiency achievable of the device depends on the thickness of the metal film used to construct the tunneling diode.