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W.J. Orvis

Bio: W.J. Orvis is an academic researcher from Lawrence Livermore National Laboratory. The author has contributed to research in topics: Triode & Silicon. The author has an hindex of 3, co-authored 3 publications receiving 358 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a method has been found for preparing uniform silicon tips with a radius of curvature less than 1 nm, formed by oxidation of 5μm-high silicon cones through exploitation of a known oxidation inhibition of silicon at regions of high curvature.
Abstract: Electron emitters in vacuum microelectronic devices need sharp tips in order to permit electron emission at moderate voltages A method has been found for preparing uniform silicon tips with a radius of curvature less than 1 nm These tips are formed by oxidation of 5‐μm‐high silicon cones through exploitation of a known oxidation inhibition of silicon at regions of high curvature

277 citations

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the modeling and fabrication of vacuum, field-emission diodes and triodes for use in electronics in hazardous environments, using the sacrificial layer technique to produce the device on a silicon wafer.
Abstract: The authors discuss the modeling and fabricating miniature, vacuum, field-emission diodes and triodes for use in electronics in hazardous environments. They are micrometer-sized devices that are fabricated on a semiconductor wafer using integrated-circuit fabrication techniques and that use field emission rather than thermionic emission to generate charge carriers. Compared to existing semiconductor devices, they should be faster and much more tolerant of high temperatures and radiation. The device design uses the sacrificial layer technique to produce the device on a silicon wafer. All of the processing is completely compatible with existing integrated-circuit technology, making possible eventual integration of these devices and existing integrated-circuit components. To model these devices, the authors have used a static field modeling code to analyze the effect of device design variations on the field at the field-emission tip. Using these field results, they have calculated the tube's plate resistance, transconductance, gain, and current versus voltage characteristics. They have completed construction of a diode and are currently testing and interpreting the results. In addition, they have nearly completed a triode design. >

71 citations

Proceedings ArticleDOI
01 Sep 1989
TL;DR: In this article, the design and building of micron-sized vacuum diodes and triodes using the sacrificial layer process is discussed, and the devices use silicon field emitters etched into the surface of a silicon wafer.
Abstract: The design and building of micron-sized vacuum diodes and triodes using the sacrificial layer process is discussed. The devices use silicon field emitters etched into the surface of a silicon wafer. The field emitters are then buried in layers of glass and conductive polysilicon to produce the grid and anode. The last step is to remove the glass layers, leaving the free-standing anode and grid with 1-2- mu m separations. Vacuum microelectronics are expected to be hard to more than 10/sup 17/ neutrons/cm/sup 2/ and 10/sup 8/ rad(Si) of gammas without sustaining permanent damage. This is three to four orders of magnitude greater than the radiation levels that comparable silicon devices can withstand. Upset is expected to be on the order of 10/sup 11/ rad(Si)/s, compared to 10/sup 8/ rad(Si)/s for silicon devices. Vacuum microelectronics should also be able to withstand in excess of 775 K, compared to a maximum of 650 K for the best silicon devices. Current work involves enhancing the sharpness of the field emitters, so that they can operate at lower voltages. Recent application of an oxidation sharpening method has created tips with a radius of curvature on the tip of less than 10 AA. >

15 citations


Cited by
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Journal ArticleDOI
TL;DR: The most widely used technique for atomic-resolution force microscopy in vacuum is frequency-modulation AFM (FM-AFM), as well as other dynamic methods as discussed by the authors.
Abstract: This article reviews the progress of atomic force microscopy in ultrahigh vacuum, starting with its invention and covering most of the recent developments. Today, dynamic force microscopy allows us to image surfaces of conductors and insulators in vacuum with atomic resolution. The most widely used technique for atomic-resolution force microscopy in vacuum is frequency-modulation atomic force microscopy (FM-AFM). This technique, as well as other dynamic methods, is explained in detail in this article. In the last few years many groups have expanded the empirical knowledge and deepened our theoretical understanding of frequency-modulation atomic force microscopy. Consequently spatial resolution and ease of use have been increased dramatically. Vacuum atomic force microscopy opens up new classes of experiments, ranging from imaging of insulators with true atomic resolution to the measurement of forces between individual atoms.

1,948 citations

Journal ArticleDOI
24 Nov 2000-Science
TL;DR: This work has engineered individual biomolecular motors and nanoscale inorganic systems, and their integration in a hybrid nanomechanical device powered by a biomolescular motor is described.
Abstract: Biomolecular motors such as F 1 –adenosine triphosphate synthase (F 1 -ATPase) and myosin are similar in size, and they generate forces compatible with currently producible nanoengineered structures. We have engineered individual biomolecular motors and nanoscale inorganic systems, and we describe their integration in a hybrid nanomechanical device powered by a biomolecular motor. The device consisted of three components: an engineered substrate, an F 1 -ATPase biomolecular motor, and fabricated nanopropellers. Rotation of the nanopropeller was initiated with 2 mM adenosine triphosphate and inhibited by sodium azide.

612 citations

Journal ArticleDOI
TL;DR: In this article, a review of field emission cold cathode materials has been presented, focusing on several kinds of novel cold cathodes that have been developed in the past decade, including materials for microfabricated field-emitter arrays, diamond and related films, carbon nanotubes, other quasi one-dimensional nanomaterials and printable composite materials.
Abstract: Field emission (FE) is based on the physical phenomenon of quantum tunneling, in which electrons are injected from the surface of materials into vacuum under the influence of an applied electric field. A variety of field emission cold cathode materials have been developed to date. In this review, we shall focus on several kinds of novel cold cathode materials that have been developed in the past decade. These include materials for microfabricated field-emitter arrays, diamond and related films, carbon nanotubes, other quasi one-dimensional nanomaterials and printable composite materials. In addition, cold cathode materials have a wide range of applications such as in flat panel displays, high-power vacuum electronic devices, microwave-generation devices, vacuum microelectronic devices and vacuum nanoelectronic devices. Applications are in consumer goods, military industries and also space technology. A comprehensive overview of the various applications is presented. Recently, recognizing the strong possibility that vacuum nanoelectronic devices using quasi one-dimensional nanomaterials, such as carbon nanotubes may emit electrons with driving voltages comparable to that of a solid-state device, there is a growing interest in novel applications of such devices. With such exciting opportunities, there is now a flurry of activities to explore applications far beyond those considered for the conventional hot cathodes that operate on thermionic emission. We shall discuss the details of a number of fascinating potential applications.

539 citations

Journal ArticleDOI
01 Jul 1994
TL;DR: The history, physics, and current status of vacuum microelectronic devices can be found in this paper, where a review of a wide variety of demonstrated and proposed devices based on vacuum micro-electronic principles, including electron guns, microwave tubes, and flat-panel displays are discussed.
Abstract: In this review/tutorial paper, we cover the history, physics, and current status of vacuum microelectronic devices. First we overview the performance requirements of vacuum microelectronic devices necessary for them to replace, or fill voids left by, solid state devices. Next we discuss the physical characteristics of micro-field-emission sources important to device applications. These characteristics include fundamental features, such as current-voltage data and noise, in addition to engineering considerations, such as life expectancy and procedures for tube assembly. We conclude with a review of a wide variety of demonstrated and proposed devices based on vacuum microelectronic principles, including electron guns, microwave tubes, and flat-panel displays. >

269 citations

Journal ArticleDOI
TL;DR: A simple method of substrate preparation for imaging circular DNA molecules with the scanning force microscope (SFM) on mica that has been soaked in magnesium acetate, sonicated and glow-discharged is presented.

252 citations