Showing papers by "Hewlett-Packard published in 1983"

Microwave signal generation with injection-locked laser diodes

Abstract: Heterodyne detection of the light from two slave lasers injection locked to FM sidebands of a modulated master laser is used to generate a narrowband microwave signal at 10.5 GHz.

Disposable ink jet head

Abstract: A thermal ink jet head is disclosed in which the jetting resistors, fluid interconnections, ink reservoir, electrical connections, and jetting orifices are fully integrated to provide an inexpensive, disposable jetting head. The entire hydraulic ink system is sealed to eliminate user interaction with the liquid ink, and ink can only exit the head via the jetting orifices under the influence of the jetting resistors. Once the ink is expended the user disposes with the old head and installs a new one by breaking and making a simple mechanical and low voltage electrical connection.

Some NP-hard polygon decomposition problems

Abstract: The inherent computational complexity of polygon decomposition problems is of theoretical interest to researchers in the field of computational geometry and of practical interest to those working in syntactic pattern recognition. Three polygon decomposition problems are shown to be NP-hard and thus unlikely to admit efficient algorithms. The problems are to find minimum decompositions of a polygonal region into (perhaps overlapping) convex, star-shaped, or spiral subsets. We permit the polygonal region to contain holes. The proofs are by transformation from Boolean three-satisfiability, a known NP-complete problem. Several open problems are discussed.

Optical fiber delay line signal processing

Abstract: Single-mode optical fiber is an attractive delay medium for processing microwave frequency signals due to its extremely low loss (<0.1 dB/µs) and large available time-bandwidth product (in excess of 10/sup 5/). Recent progress in the efficient tapping of light from single-mode fibers has made it possible to construct recirculating and nonrecirculating (tapped) delay-line structures that can perform a variety of important signal processing functions. These functions include coded sequence generation, convolution, correlation, matrix-vector multiplication, and frequency filtering. This paper presents the fundamental properties of single-mode fiber delay lines and reviews recent experimental results that demonstrate the feasibility of fiber delay-line devices for broad-band signal-processing applications.

Ink jet printer with bubble driven flexible membrane

Abstract: An apparatus is disclosed for propelling ink droplets from an ink jet nozzle which uses an expanding bubble as a driving mechanism. Unlike other thermal ink jet devices, the ink itself is not used to provide the driving bubble. Rather a two fluid system is disclosed whereby a flexible membrane is used to maintain separation between a working fluid and the ink. A bubble is thermally created in the working fluid which distends the membrane and causes ink on the other side of the membrane to be expelled from an ink jet orifice. The membrane is in direct physical contact with the surface of the bubble-generating resistor and a quantity of the working fluid lies between the resistor and the membrane in pockets created by roughening the surface of the membrane or by roughening the surface of the resistor; alternatively, pockets between the membrane and the resistor may be provided by particulates contained within the working fluid which provide local separations of the membrane and the resistor.

Ink dispenser with "frozen" solid ink

Abstract: A new type of apparatus for dispensing "frozen" solid ink and the ink for use therein for printing on paper is disclosed. The ink dye vehicle is chosen to have a melting point above room temperature, so that the ink which is melted in the apparatus will not be subject to evaporation or spillage during periods of non-printing. The vehicle is also chosen to have a low critical temperature to permit the use of the solid ink in a thermal ink jet printer.

Measurement of noise in magnetic media

Abstract: A model for medium noise in thin film and particulate discs is presented. The model is based on both time jitter and spectrum analyzer measurements. Thin metallic film discs have different noise mechanisms from either particulate or sputtered γ-Fe 2 O 3 discs. A signal-to-noise ratio equal to the signal /rms noise measured at the predetection filter output gives accurate prediction of peak jitter only if the noise is measured at the transitlon density giving maximum noise.

Particle-free dockable interface for integrated circuit processing

Abstract: A particle-free dockable interface is disclosed for linking together two spaces each enclosing a clean air environment. The interface is composed of interlocking doors on each space which fit together to trap particles which have accumulated from the dirty ambient environment on the outer surfaces of the doors.

Supercritical Fluid Chromatography

Abstract: Chromatographic separations with a supercritical fluid as the mobile phase were suggested more than 20 years ago. Availability of commercial hardware makes this technique more widely usable today. Many separations by this method are now carried out with supercritical carbon dioxide as the mobile phase and packed liquid-chromatography columns as the stationary phase. Although carbon dioxide has many practical advantages, including its near-ambient critical temperature and minimal interference with spectrometric detection, the use of other supercritical fluids or addition of modifiers to carbon dioxide may extend the applications of this technique. Some mixtures that are difficult to analyze by other chromatographic methods may be susceptible to separation by supercritical fluid chromatography. Mixtures that have been separated with supercritical carbon dioxide include resin acids with the empirical formula C20H30O2 and ubiquinones from bacterial cell wall extracts of Legionella pneumophila.

100 GHz bandwidth planar GaAs Schottky photodiode

Abstract: In the letter we report the development and characterisation of a planar-structure GaAs Schottky-barrier photodiode whose response to a mode-locked laser pulse of 600 nm wavelength has a full-width half-maximum of 5.4 ps and a 3 dB bandwidth of 100 GHz.

Wafer/mask alignment system using diffraction gratings

Abstract: An alignment method in which light is diffracted from a mask grating to a wafer grating and back through the mask grating to produce a set of output diffraction orders. The intensity of the zeroth output order is monitored and the mask is translated and rotated within the plane containing the mask to align the mask with the wafer. Alignment occurs when the intensity of the zeroth output order is at an extremum. The distance between the mask and wafer is also adjusted to extremize the intensity of the zeroth output order to make the wafer lie within the focal plane of the exposure optics. The wafer mask is preferrably a holographic phase grating to simplify production of the grating and to eliminate resist related interference. Two dimensional gratings can be used to achieve alignment with only one grating on each wafer.

Thermal ink jet printhead

Abstract: A protective passivation structure is provided for a thermal ink jet printing head which employs a resistive heating element formed of phosphorus-diffused silicon. The passivation structure includes a layer of silicon nitride over the heating element with a layer of silicon carbide over the silicon nitride layer. The nitride exhibits good adhesion to the underlying silicon as well as good thermal conductivity. The carbide has exceptionally good wear and hardness qualities against ink bubble cavitation as well as adhering well to the nitride.

Linear Ordering and Application to Placement

Abstract: Given a set of interconnected elements, linear ordering generates a linear sequence of elements of the set, which is the basis for most constructive initial-placement methods. This paper presents a new strategy for linear ordering. The important difference of the new technique from the previous ones is that it starts the ordering process from the most lightly connected seed. It was applied to various placement problems including standard cell and gate array and produced very good results.

Thermal ink jet printhead with self-passivating elements

Abstract: A passivation layer in a thermal ink jet printhead is formed or "grown" by a reaction between the materials of the ink jet structure to be protected and an element which will form a chemically inert, electrically insulating, thermally conductive compound. The resistor structure may be of tantalum or tantalum nitride and the electrical conductors therefor may be of aluminum. By subjecting this resistor-conductor structure to a reactive oxide atmosphere, the exposed surfaces of both are anodized so that a surface film of aluminum oxide is formed on the aluminum conductor and a surface film of tantalum pentoxide or tantalum oxynitride is formed on the resistor structure.

Fluidic tuning of impulse jet devices using passive orifices

Abstract: A nozzle plate for impulsive jet devices is proposed where the quality of ejected droplets is improved by means of additional non-emitting orifices. These orifices may act as fluid accumulators and tuned or untuned absorbers of pressure disturbances to optimize drop quality and reduce fluidic crosstalk between adjacent drop generators. The presence of these orifices permits additional degrees-of-freedom in the design of high-quality impulsive jet devices. Sufficient crosstalk reduction results that crosstalk reduction barriers can be eliminated.

Structure of thermally induced microdefects in Czochralski silicon after high‐temperature annealing

Abstract: The microstructure of Czochralski silicon annealed at high temperatures has been investigated using high resolution transmission electron microscopy. After prolonged heat treatments at temperatures close to 1200 °C, two types of microdefects are observed: (a) small polyhedral oxide precipitates, with typical diameters of about 15 nm and facets along crystalline planes of the silicon matrix, and (b) planar faults along {111} planes which have been directly identified as extrinsic stacking faults bounded by Frank‐type dislocations.

Method and apparatus for generating a gray scale with a high speed thermal ink jet printer

Abstract: A thermal ink jet printer emits discrete drops of a variable volume in order to create a printed gray scale. A pulse train of packets of pulses is used to generate drops comprising packets of connected or merged droplets; the reciprocal of the pulse repetition rate is greater than the bubble collapse time and the pulse packet rate is less than the maximum single droplet emission rate of the print head. The individual droplets within the packet merge in flight to create a single drop whose volume depends upon the number of pulses contained within the pulse packet. The summing of impulses generated by the individual pulses is also useful so that drops of ink may be emitted by a resistor which is physically undersized for the particular ink being used.

Trench isolated transistors in semiconductor films

Abstract: A method for trench isolation of a silicon island for device fabrication using only conventional very large scale integration (VLSI) techniques is provided. The combination of the sidewall isolation achieved with the trench isolation and the underlying oxide film create a totally dielectrically isolated structure without the possibility of latch-up between adjacent devices.

Two-dimensional oxidation

Abstract: This paper introduces the first general two-dimensional oxidation model based on steady-state oxygen diffusion and the slow incompressible viscous flow of oxide. The moving-boundary problem is solved through a novel numerical technique based on pressure/velocity iteration and a boundary-value approach. The simulation results obtained for oxide shape and bird's beak size versus pad-oxide thickness are in excellent agreement with experiments. This model is also able to calculate stress on the silicon interface during oxidation; this calculated value (6 × 109dyne/cm2) also agrees with the measurement and reveals the tendency of stress to decrease with increasing pad-oxide thickness.

Electro-optic sampling with picosecond resolution

Abstract: The development of an electro-optic sampling system with resolution of better than 2 picoseconds and shot noise limited sensitivity of 11 μV/√Hz is reported. This system has been used to characterise GaAs photodiodes which have exhibited pulsewidths as short as 5.4 picoseconds (full-width-half-maximum).

Self cleaning electrochemical detector and cell for flowing stream analysis

Abstract: An improved electrochemical cell and detector which is especially suited for analysis of rapidly changing flowing streams such as found in high performance liquid chromatography is disclosed. A uniquely designed jet made of microbore drawn capillary tubing permits the construction of a cell for very low flow rates that still retains true wall-jet hydrodynamics. The invention prevents changes in cell response in time by periodically cleaning a working electrode in a novel way. Cleaning and detection are both accomplished on a time scale much shorter than the fastest liquid chromatograph peaks by means of a unique three electrode cell design utilizing a small diameter, low capacitance, metal working electrode situated close to a reference electrode. Cleaning is accomplished by means of a non-square wave periodic waveform which is effective in cleaning a wide variety of contaminants through the oxidation and reduction of the working electrode and/or solvent prior to application of one or more working potentials while providing a stable, reproducible detector. The detector thus provides improvements in both sensitivity and bandwidth over the prior art.

Barriers for thermal ink jet printers

Abstract: A thermal ink jet print head is provided having a new and improved barrier design. Two barriers are provided for each resistor, the barriers partially surrounding the resistor. The barriers are spaced apart to provide ink feed channels to the resistor and are arranged to impart angular momentum to the ink relative to the resistor during refill on bubble collapse.

DC holding and dynamic triggering characteristics of bulk CMOS latchup

Abstract: Improved models for bulk CMOS latchup holding and triggering characteristics are developed and verified experimentally in this work. The roles of collector and base branch resistances are shown to lead to an accurate model for the minimum voltage to sustain latchup, and to an improved understanding of strong versus weak layouts, respectively. New measurement techniques for model parameters are described and used to test the dc model. Latchup triggering by base region (substrate or well) lateral currents is considered in some detail, It is shown that both threshold current levels and minimum turn-on times exist, below which latchup will not occur. Supporting experimental evidence is presented for all of the models.

CVD lateral epitaxial growth of silicon over insulators

Abstract: A method for growing Silicon On Insulator (SOI) films using only conventional very large scale integration (VLSI) techniques is provided. By sequentially varying the flow of HCL gas during the vertical-growth, lateral-overgrowth, coalescence, and planarization stages of the epitaxial deposition process allows the formation of high-quality SOI films on wider oxide stripes suitable for general transistor applications.

Ink jet orifice plate having integral separators

Abstract: An orifice plate is provided of an electroformed material which incorporates an integral ink distribution manifold and integral hydraulic separators between orifices. The general approach to the method of making the orifice plate is to first construct a two-part mandrel made up of a "hard" mandrel which can be reused many times and a "soft" mandrel which is renewed each time the mandrel is used. Typically, the surface of the "hard" mandrel is configured by mask and etch techniques, or by mask and electroplate techniques to define the ink distribution manifold and the hydraulic separators, while the "soft" mandrel is configured by mask and develop techniques to define the orifices and edges between orifice plates. Upon completion of the mandrel, its surface is electroplated with a relatively uniform thickness of metal, and the newly electroplated surface having the orifice plates patterned therein is separated from the mandrel.

Electrical load drive and control system

Abstract: A circuit for varying the power supplied from a D.C. power supply to a moderate to high powered load such as a motor is disclosed. Trapezoidal voltage and current waveforms are used approaching the maximum load power delivery available from sine wave drives and the minimum dissipation in the driver circuitry available with square wave drives, while at the same time minimizing the generation of undesirable electromagnetic interference (EMI).

The sloped-wall SWAMI&#8212;A defect-free zero bird's-beak local oxidation process for scaled VLSI technology

Abstract: A new scheme for a Side WAll Masked Isolation (SWAMI) process is presented which takes all the advantages provided by LOCOS without suffering its difficulties. The new SWAMI technology incorporates a sloped silicon sidewall and a thin nitride layer around the island sidewalls such that both intrinsic nitride stress and volume expansion-induced stress are greatly reduced. A defect-free fully recessed zero bird's-beak local oxidation process can be realized by the sloped-wall SWAMI. Fabrication technology and NMOS electrical characteristics will be discussed. Two-dimensional simulation of total reduction in effective channel width for ideal vertical isolation, LOCOS, and SWAMI will also be presented. A SWAMI/CMOS circuit including 60K ROM, 2.5K SRAM, and 100 segments of display driver with 5.13 × 5.22 mm2chip size has been successfully fabricated. The results indicate that SWAMI is capable of replacing LOCOS as the isolation technology for submicrometer VLSI circuit fabrication.

Automated sample concentrator for trace components

Abstract: Concentration of the solutes contained in a liquid solvent is effected by passing the solvent through a first trapping means that adsorbs them, flushing the first trapping means with supercritical fluid and reducing its solubility parameter in a second trapping means so that the latter can adsorb desired solutes.