Abstract: The SAW device comprises a diamond or quartz substrate as a wave propagation layer, a piezoelectric layer on the wave propagation layer and at least one interdigitated electrode on the piezoelectric layer.

Abstract: A method for fabricating a microelectronic structure includes the steps of forming a semiconductor island on a substrate and forming a filler material on the substrate and surrounding the semiconductor island. The semiconductor island includes a first semiconductor material and has a planar island surface opposite the substrate. The filler material includes a second semiconductor material and has a planar single crystal surface adjacent the planar island surface opposite the substrate so that the planar island surface and the planar single crystal surface together define a smooth planar surface. The first semiconductor material can be diamond, and the second semiconductor material can be silicon. In addition, a microelectronic circuit can be formed on the filler material.

Abstract: A microelectronic structure includes a substrate, a semiconductor island on the substrate, and a filler material on the substrate and surrounding the semiconductor island. The semiconductor island includes a first semiconductor material and has a planar island surface opposite the substrate. The filler material includes a layer of a second semiconductor material having a planar single crystal surface adjacent the planar island surface opposite the substrate so that the planar island surface and the planar single crystal surface together define a smooth planar surface. The first semiconductor material can be diamond, and the second semiconductor material can be silicon. In addition, a microelectronic circuit can be provided on the filler material.

Abstract: Embedded IDT electrodes are provided in a multilayer structure consisting of a diamond layer on a substrate with IDT electrodes formed on the diamond and a very thin interlayer covering the interdigitated transducer structure and the diamond, thus embedding the IDT electrodes between the diamond layer and the interlayer, with a piezoelectric layer on the interlayer so that an acoustic surface wave propagates in the diamond layer. The very thin interlayer between the diamond and the piezoelectric layer greatly increases the uniformity of the piezoelectric layer but does not interfere with the acoustic properties of a SAW device.

Abstract: A method of forming devices having textured and highly oriented diamond layers includes the steps of forming a plurality of diamond nucleation sites on a substrate and then growing diamond on the sites so merge and form a continuous diamond layer having {100} and {111} facets. The growing step is performed by repeatedly cycling between first growth parameters, which favor growth of the nucleation sites in a direction normal to the {100} facets relative to growth in a direction normal to the {111} facets, and second growth parameters, which favor growth of the {100} facets relative to growth of the {111} facets, in sequence. This is continued until a diamond layer of desired thickness is obtained having large and substantially coplanar {100} facets. The first growth parameters are selected so that the rate of growth of diamond in a direction normal to the exposed {100} facets of the layer is preferably between about one and one quarter (1.25) times and one and three quarter (1.

Abstract: An acceleration sensor includes an acceleration mass and a substrate mounted so that a cavity is defined therebetween and so that the acceleration mass moves relative to the substrate when an acceleration of the sensor changes. The sensor also includes a diamond field emitter for generating an electron beam through the cavity between the acceleration mass and the substrate. Accordingly, the distance between the acceleration mass and the substrate affects the current of the electron beam which is measured to determine the acceleration of the sensor. The sensor may alternately include an annular extraction electrode in a cavity between a substrate and a collector together with a diamond field emitter for generating an electron beam which passes through the annular extraction electrode. The annular extraction electrode is moveable relative to the substrate in response to changes in an acceleration acting on the sensor.

Abstract: A diamond-based structure includes a substrate, an adhesive material on a face of the substrate, and an array of spaced apart diamond mesas bonded to the substrate by the adhesive material. In particular, each of the diamond mesas can have a growth surface adjacent the substrate and an interfacial surface opposite the substrate, and the interfacial surface can be smooth relative to the growth surface. This structure can be fabricated by providing a sacrificial substrate, forming a plurality of diamond mesas on a face of the sacrificial substrate, bonding the diamond mesas to a transfer substrate, and removing the sacrificial substrate. Accordingly, the interfacial surfaces of the diamond, which are formed adjacent the sacrificial substrate and then exposed by removing the substrate are smooth.

Abstract: A diamond-based structure includes a substrate, an adhesive material on a face of the substrate, and an array of spaced apart diamond mesas bonded to the substrate by the adhesive material. In particular, each of the diamond mesas can have a growth surface adjacent the substrate and an interfacial surface opposite the substrate, and the interfacial surface can be smooth relative to the growth surface. This structure can be fabricated by providing a sacrificial substrate, forming a plurality of diamond mesas on a face of the sacrificial substrate, bonding the diamond mesas to a transfer substrate, and removing the sacrificial substrate. Accordingly, the interfacial surfaces of the diamond, which are formed adjacent the sacrificial substrate and then exposed by removing the substrate are smooth.

Abstract: A texture treatment for a carbon substrate of a magnetic disk or for a carbon overcoat layer of a magnetic disk is effective to prevent the generation of a stiction phenomenon between a magnetic head and the surface of a magnetic disk. The texture treatment for a carbon substrate or carbon overcoat of a magnetic disk involves the steps of: preparing the carbon disk surface; forming a catalytic material layer on the surface; and performing a heat treatment of the disks in an oxidizing atmosphere. Preferably, islands of catalytic material are formed on the surface by sputtering, and a laser heat treatment is used in an oxidizing atmosphere.

Abstract: An electron beam device includes a diamond layer positioned downstream from and in the path of an electron beam. This diamond layer has a conductance that is responsive to the electron beam. Two electrical contacts on the diamond layer provide connections to a power source and a load. When the electron beam is on, the diamond layer becomes conductive allowing electrical power to flow from the power source through the diamond layer to the load. Accordingly, the electron beam device can act as a switch, or the electron beam can be modulated to provide an amplifier. The diamond layer is capable of high temperature operation, resists crystal damage, resists corrosion, and provides a high breakdown voltage. At least one of the electrical contacts on the diamond layer preferably comprises a degeneratively doped diamond surface portion.

Abstract: A high frequency Surface Acoustic Wave (SAW) device includes a highly oriented diamond layer adjacent a piezoelectric layer. In one embodiment, laterally spaced apart piezoelectric layers or portions confine propagation of the wave within the diamond layer. Interdigitated electrodes may be provided by electrically conductive metal lines and/or by heavily doped surface portions of the diamond layer. Undesirable reflections may be reduced by providing the piezoelectric layer with opposing ends canted at an angle from orthogonal to the axis of surface acoustic wave propagation. The surface acoustic wave device may be used as a filter, amplifier, convolver, and phase shifter. Methods for making the surface acoustic wave device are also disclosed.

Abstract: A microelectronic structure including a plurality of spaced apart diamond structures on which a plurality of semiconductor devices may be formed. The semiconductor devices include a semiconducting diamond layer on each of the diamond structures. The diamond structures are preferably oriented relative to a single crystal nondiamond substrate so that the diamond structures have a (100)-oriented outer face for forming the semiconductor devices thereon. The microelectronic structure may be diced into discrete devices, or the devices interconnected, such as to form a higher powered device. One embodiment of the microelectronic structure includes the plurality of diamond structures, wherein each diamond structure is formed of a highly oriented textured diamond layer approaching single crystal quality, yet capable of fabrication on a single crystal nondiamond substrate.

Abstract: A semiconductor device for providing stable operation over a relatively wide temperature range includes a wide bandgap semiconductor active region having an intentional dopant of a first conductivity type and an unintentional impurity of a second conductivity type which together produce a free carrier concentration at room temperature. The concentration of the intentional dopant in the active region is preferably less than 1.times.10.sup.16 cm.sup.-3 and the concentration of the unintentional impurity is less than 0.1 times the intentional dopant concentration so that the intentional dopant concentration will be less than 1000 times the free carrier concentration at room temperature. The intentional dopant concentration supplies substantially all the majority free carriers in the active region. The wide bandgap semiconductor active region is preferably diamond, IV-IV carbides, III-V nitrides and phosphides and II-VI selenides, tellurides, oxides and sulfides.

Abstract: The present invention relates to a heat dissipating substrate with a highly-oriented diamond film of a low crystal inclination and a low density grain boundaries and having a significantly high thermal conductivity. At least 90% of the surface area of the highly-oriented diamond film is covered with either (100) or (111) crystal planes, and the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of the Euler angles, which represent the orientations of the crystals, between adjacent (100) or (111) crystal planes, simultaneously satisfies the following relationship: .vertline..DELTA..alpha..vertline..ltoreq.5.degree., .vertline..DELTA..beta..vertline..ltoreq.5.degree., and .vertline..DELTA..gamma..vertline..ltoreq.5.degree.. In addition, this highly-oriented diamond film can be grown on a non-diamond substrates, and therefore the diamond film with a large surface area can be obtained. Thus, the present invention provides the heat dissipating substrate with an excellent thermal conductivity at low cost.

Abstract: The highly-oriented diamond film is a diamond film formed by chemical vapor deposition, with at least 95% of its area consisting of either (100) or (111) crystal planes, and the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of the Euler angles {.alpha., .beta., .gamma.} between the adjacent crystals satisfying (.vertline..DELTA..alpha..vertline..ltoreq.1.degree., .vertline..DELTA..beta..vertline..ltoreq.1.degree. and .vertline..DELTA..gamma..vertline..ltoreq.1.degree.) simultaneously. Thus obtained highly-oriented diamond film has few grain boundaries and high carrier mobility. And the area of the diamond film can be large.

Abstract: A junction suitable for incorporation in diamond electronic devices, such as field effect transistors, U-V photodetectors, capacitors, charge-coupled devices, etc., comprising a double layer structure deposited on the semiconducting diamond film of the electronic device, wherein the double layer structure consists of a layer of intrinsic diamond and a layer of a carrier blocking material. The carrier blocking materials is characterized by a band structure discontinuous with that of diamond resulting in the formation of a depletion layer at the interface. A contact is then formed on this double layer structure.

Abstract: The rectifying element is comprised of two electrodes, an undoped diamond film, and a B-doped p-type diamond film. The diamond films are formed of highly-oriented diamond films, of which at least 80% of the surface area consists of (100) or (111) crystal planes, and the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of Euler angles {.alpha., .beta., .gamma.}, which represent the orientations of crystal planes, simultaneously satisfy .vertline..DELTA..alpha..vertline..ltoreq.5.degree., .vertline..DELTA..bet a..vertline..ltoreq.5.degree. and .vertline..DELTA..gamma..vertline..ltoreq.5.degree. between adjacent crystal planes. The diamond rectifying element thus constructed have an excellent electrical characteristics, and multiple of the elements can be produced on a large area at low cost. The diamond rectifying elements can be used for heat-resistant and high-power rectifying elements.

Abstract: A source electrode is formed on the first semiconducting diamond film and a drain electrode is formed on the second semiconducting diamond film. A highly resistant diamond film having a thickness of between 10 .ANG. and 1 mm and an electrical resistance of at least 10.sup.2 .OMEGA..cm or more is placed between the first and second semiconducting diamond films. A gate electrode is formed on the highly resistant diamond film. Thereby, a channel region is formed by these first and second semiconducting diamond films as well as the highly resistant diamond film. All or at least a part of said first and second semiconducting diamond films and the highly resistant diamond film are made of highly-oriented diamond films where either (100) or (111) crystal planes of diamond cover at least 80% of the film surface, and the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of Euler angles {.alpha., .beta., .gamma.} which represent the crystal plane orientation, satisfy .vertline..DELTA..alpha..vertline.<10.

Abstract: Techniques for synthesizing diamond films include a method for anisotropically etching a diamond film. The method includes the steps of selectively patterning a mask layer on a surface of a diamond film and then subjecting the mask layer and exposed surface portions of the diamond film to a hydrogen-containing plasma, while negatively biasing the diamond film to convert the exposed surface portions of the diamond layer to nondiamond carbon. Negatively biasing the diamond film in the hydrogen-containing plasma causes an emission of electrons to thereby convert exposed diamond surface portions to nondiamond carbon. The hydrogen-containing plasma continuously removes the nondiamond carbon from the surface and maintains the electron emission efficiency of the exposed diamond surface so that further etching can take place.

Abstract: A diamond semiconductor device with a carbide interlayer includes a diamond layer having a semiconducting diamond region of first conductivity type therein and an insulated gate structure on a face of the diamond layer. The relatively thin carbide interfacial layer is provided between the insulated gate structure and the diamond layer in order to inhibit the formation of electrically active defects, such as interface states at the face. By inhibiting the formation of interface states at the face, the carbide interfacial layer suppresses parasitic leakage of charge carriers from the diamond layer to the insulated gate structure. The carbide interfacial layer can be intrinsic silicon carbide or an intrinsic refractory metal carbide (e.g., TiC or WC) or the layer can be of opposite conductivity type to thereby form a P--N heterojunction with the diamond layer.