Abstract: Si—Ge materials are grown on Si(100) with Ge-rich contents (Ge>50 at. %) and precise stoichiometries SiGe, SiGe2, SiGe3 and SiGe4. New hydrides with direct Si—Ge bonds derived from the family of compounds (H3Ge)xSiH4-x (x=1-4) are used to grow uniform, relaxed, and highly planar films with low defect densities at unprecedented low temperatures between about 300-450° C. At about 500-700° C., SiGex quantum dots are grown with narrow size distribution, defect-free microstructures and highly homogeneous elemental content at the atomic level. The method provides for precise control of morphology, composition, structure and strain. The grown materials possess the required characteristics for high frequency electronic and optical applications, and for templates and buffer layers for high mobility Si and Ge channel devices.

Abstract: The present invention provides novel silicon-germanium hydride compounds, methods for their synthesis, methods for their deposition, and semiconductor structures made using the novel compounds.

Abstract: The present invention provides novel silicon-germanium hydride compounds, methods for their synthesis, methods for their deposition, and semiconductor structures made using the novel compounds.

Abstract: The present invention provides novel silicon-germanium hydride compounds, methods for their synthesis, methods for their deposition, and semiconductor structures made using the novel compounds.

Abstract: A semiconductor structure and fabrication method is provided for integrating wide bandgap nitrides with silicon. The structure includes a substrate, a single crystal buffer layer formed by epitaxy over the substrate and a group III nitride film formed by epitaxy over the buffer layer. The buffer layer is reflective and conductive. The buffer layer may comprise B an element selected from the group consisting of Zr, Hf, Al. For example, the buffer layer may comprise ZrB2, AlB2 or HfB2. The buffer layer provides a lattice match with the group III nitride layer. The substrate can comprise silicon, silicon carbide (SiC), gallium arsenide (GaAs), sapphire or Al2O3. The group III nitride material includes GaN, AlN, InN, AlGaN, InGaN or AlInGaN and can form an active region. In a presently preferred embodiment, the buffer layer is ZrB2 and the substrate is Si(111) or Si(100) and the group III nitride layer comprises GaN.

Abstract: The present invention provides novel silicon-germanium hydride compounds, methods for their synthesis, methods for their deposition, and semiconductor structures made using the novel compounds.

Abstract: A method for depositing an epitaxial Ge—Sn layer on a substrate in a CVD reaction chamber includes introducing into the chamber a gaseous precursor comprising SnD4 under conditions whereby the epitaxial Ge—Sn layer is formed on the substrate. the gaseous precursor comprises SnD4 and high purity H2 of about 15-20% by volume. The gaseous precursor is introduced at a temperature in a range of about 250° C. to about 350° C. Using the process device-quality Sn—Ge materials with tunable bandgaps can be grown directly on Si substrates.

Abstract: A method is provided for growing Si—Ge materials on Si(100) with Ge-rich contents (Ge>50 at. %) and precise stoichiometries SiGe, SiGe2, SiGe3 and SiGe4. New hydrides with direct Si—Ge bonds derived from the family of compounds (H3Ge)xSiH4-x (x=1-4) are used to grow uniform, relayed and highly planar films with low defect densities at unprecedented low temperatures between about 300-450° C., circumventing entirely the need of thick compositionally graded buffer layer and lift off technologies. At about 500-700° C., SiGex quantum dots are grown with narrow size distribution, defect-free microstructures and highly homogeneous elemental content at the atomic level. The method provides precise control of morphology, composition, structure and strain via the incorporation of the entire Si/Ge framework of the gaseous precursor into the film.

Abstract: A method of growing quaternary epitaxial films having the formula YCZN wherein Y is a Group IV element and Z is a Group III element at temperatures in the range 550-750° C. is provided. In the method, a gaseous flux of precursor H3YCN and a vapor flux of Z atoms are introduced into a gas-source molecular beam epitaxial (GSMBE) chamber where they combine to form thin film of YCZN on the substrate. Preferred substrates are silicon, silicon carbide and AlN/silicon structures. Epitaxial thin film SiCAlN and GeCAlN are provided. Bandgap engineering may be achieved by the method by adjusting reaction parameters of the GSMBE process and the relative concentrations of the constituents of the quaternary alloy films. Semiconductor devices produced by the present method have bandgaps from about 2 eV to about 6 eV and exhibit a spectral range from visible to ultraviolet which makes them useful for a variety of optoelectronic and microelectronic applications.

Abstract: A low temperature method for growing quaternary epitaxial films having the formula XCZN wherein X is a Group IV element and Z is a Group III element. A Gaseous flux of precursor H3XCN and a vapor flux of Z atoms are introduced into a gas-source molecular beam epitaxial (MBE) chamber to form thin film of XCZN on a substrate preferably of silicon or silicon carbide. Silicon substrates may comprise a native oxide layer, thermal oxide layer, AlN/silicon structures or an interface of Al—O—Si—N formed from interlayers of Al on the Si02 layer. Epitaxial thin film SiCAlN and AlN are provided. Bandgap engineering is disclosed. Semiconductor devices produced by the present method exhibit bandgaps and spectral ranges which make them useful for optoelectronic and microelectronic applications. SiCAlN deposited on large-diameter silicon wafers are substrates for growth of conventional Group III nitrides such as AlN. The quaternary compounds exhibit extreme hardness.

Abstract: A semiconductor structure integrates wide bandgap semiconductors with silicon. The semiconductor structure includes: a substrate; a SiCAlN region formed over the substrate, and an active region formed over the SiCAlN region. The substrate can comprise silicon, silicon carbide (SiC) or silicon germanium (SiGe). The active region can include a gallium nitride material region, such as GaN, AlGaN, InGaN or AlInGaN. It also can include AlN and InN region. The structure also can include a crystalline oxide interface formed between the substrate and the SiCAlN region. A preferred crystalline oxide interface is Si—Al—O—N. The active layer can be formed by known fabrication processes, including metal organic chemical vapor deposition or by atomic layer epitaxy. The crystalline oxide interface is normally formed by growing SiCAlN on Si(111) via a crystalline oxide interface, but can also be formed by metal organic chemical vapor deposition or by atomic layer epitaxy.

Abstract: A method of growing quaternary epitaxial films having the formula YCZN wherein Y is a Group IV element and Z is a Group III element at temperatures in the range 550-750° C. is provided. In the method, a gaseous flux of precursor H3YCN and a vapor flux of Z atoms are introduced into a gas-source molecular beam epitaxial (GSMBE) chamber where they combine to form thin film of YCZN on the substrate. Preferred substrates are silicon, silicon carbide and AlN/silicon structures. Epitaxial thin film SiCAlN and GeCAlN are provided. Bandgap engineering may be achieved by the method by adjusting reaction parameters of the GSMBE process and the relative concentrations of the constituents of the quaternary alloy films. Semiconductor devices produced by the present method have bandgaps from about 2 eV to about 6 eV and exhibit a spectral range from visible to ultraviolet which makes them useful for a variety of optoelectronic and microelectronic applications.

Abstract: In semiconductor devices such as laser diodes (LD) and light emitting diodes (LED) based on gallium nitride thin films, low defect density is desired in the gallium nitride film. In the fabrication of such devices on a silicon carbide substrate surface, the gallium nitride film is formed on the silicon carbide substrate after the substrate surface is etched using hydrogen at an elevated temperature. In another embodiment, an aluminum nitride film is formed as a buffer layer between the gallium nitride film and the silicon carbide substrate, and, prior to aluminum nitride formation, the substrate surface is etched using hydrogen at an elevated temperature.

Abstract: An isolation system for isolating a first object from vibrations from a second object. Such vibrations will have three orthogonal components, one oriented along a line between the objects, and two oriented 90.degree. apart in a plane normal to that line. The system includes three superconductor/magnet stages, each stage designed to extinguish one of the orthogonal components.