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Journal

1990

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Articles 1 - 30 of 57

Full-Text Articles in Engineering

Irish Building Services News Dec 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Ole Miss Engineer 1990 Oct 1990

Ole Miss Engineer 1990

Ole Miss Engineer

No abstract provided.


Irish Building Services News Oct 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


The Role Of Scientists In Risk Assessment, Halina Szejwald Brown, Robert L. Goble Sep 1990

The Role Of Scientists In Risk Assessment, Halina Szejwald Brown, Robert L. Goble

RISK: Health, Safety & Environment (1990-2002)

The authors argue that Risk assessors belong to a profession and offer an alternative to the 1983 National Research Council model defining Risk assessment. They support and illustrate their model by reexamining three familiar Risk assessments: ethylene dibromide, WASH 1400, and Ice Minus Bacteria.


Irish Building Services News Sep 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Perceived Risks Versus Actual Risks: Managing Hazards Through Negotiation, Kristin S. Shrader-Frechette Sep 1990

Perceived Risks Versus Actual Risks: Managing Hazards Through Negotiation, Kristin S. Shrader-Frechette

RISK: Health, Safety & Environment (1990-2002)

The author describes what she calls the "Expert-Judgment Strategy", finding that, because it discounts lay perceptions of Risk, it interferes with the acceptance of important but Risky technologies.


32nd Rocky Mountain Conference Jul 1990

32nd Rocky Mountain Conference

Rocky Mountain Conference on Magnetic Resonance

Program and registration information for the 32nd annual meeting of the Rocky Mountain Conference, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, July 29 - August 3, 1990.


Irish Building Services News Jul 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Coke Oven Emissions: A Case Study Of Technology-Based Regulation, John D. Graham, David R. Holtgrave Jun 1990

Coke Oven Emissions: A Case Study Of Technology-Based Regulation, John D. Graham, David R. Holtgrave

RISK: Health, Safety & Environment (1990-2002)

After examining and analyzing the experience with coke ovens, the authors conclude that attempts to force technology beyond its demonstrated competence can be both expensive and ineffective in controlling hazards. They also suggest implications for pending proposals to further control air pollution.


Irish Building Services News Jun 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Irish Building Services News May 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Ole Miss Engineer 1990 Apr 1990

Ole Miss Engineer 1990

Ole Miss Engineer

No abstract provided.


Irish Building Services News Mar 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Irish Building Services News Feb 1990

Irish Building Services News

Building Services Engineering

No abstract provided.


Risk Objectivism And Risk Subjectivism: When Are Risks Real, Paul B. Thompson Jan 1990

Risk Objectivism And Risk Subjectivism: When Are Risks Real, Paul B. Thompson

RISK: Health, Safety & Environment (1990-2002)

Typically, those who discuss Risk management envision a two-step process wherein, first, Risk is more or less objectively appraised and, second, the acceptability of those Risks is subjectively evaluated. This paper questions the philosophical foundations of that approach.


Increasing The Practical Resolution Of Projection Lithography Using A Phase-Shifting Mask, Eric M. Apelgren Jan 1990

Increasing The Practical Resolution Of Projection Lithography Using A Phase-Shifting Mask, Eric M. Apelgren

Journal of the Microelectronic Engineering Conference

A phase shifting mask, to be used for the purpose of improving the resolution of a projection lithography system, was fabricated. This type of mask consists of line-space pairs in which every other aperture induces a 180 degree phase shift in the transmitted radiation. In order to obtain this phase shift there must be a thickness difference between the apertures. Etching of the glass mask plate in 3:100 HF to DI water was used to obtain the required • etch depth.


Bilayer E-Beam/Duv Resist Systems, James Baccaro Jan 1990

Bilayer E-Beam/Duv Resist Systems, James Baccaro

Journal of the Microelectronic Engineering Conference

Two bilayer E-beam/DUV resist schemes were developed using a DUV sensitive PMGI planarization layer and two E-beam sensitive imaging layers. PMM~ and Olin-Hunt Waycoat HEBR-214 were used as imaging layers. The HEBR-214/ PMGI system is totally aqueous developable. Both systems offer several advantages over other bilayer systems including thermal stability, low interfacial - layer formation, and low toxicity.


Micromachining: The Fabrication Of A Micromotor, Brian C. Barker Jan 1990

Micromachining: The Fabrication Of A Micromotor, Brian C. Barker

Journal of the Microelectronic Engineering Conference

Micromachining techniques were used to fabricate two versions of a small electromechanical device, a Micromotor. This structure, originally developed by a pair of graduate students at the University of California at Berkeley, then modified by a fifth year student a Rochester Institute of Technology, was formed through multiple polysilicon depositions. After an etch of approximately two hours, the rotors were shown to have released, and moved by mechanical means, however, movement was not achieved through electrical means.


Reactive Ion Etching Of Silicon Dioxide Using Both Oxygen And Carbon Dioxide As Gas Additives, James E. Constantino Jan 1990

Reactive Ion Etching Of Silicon Dioxide Using Both Oxygen And Carbon Dioxide As Gas Additives, James E. Constantino

Journal of the Microelectronic Engineering Conference

A study was performed on the etch characteristics of silicon dioxide and polysilicon for a reactive ion etch system, using CHF4 as the primary etchant gas and using either oxygen or carbon dioxide as an additive gas. Correlations were found between the amount and type of additive gas introduced to the system, the Rf power of the - system, the pressure that the system is maintained at and the effects these parameters have on the etch rate and - selectivity of Si02 and polysilicon etches. It was found that adding CO2 in small amounts to the gas mixture instead of …


Design And Construction Of A Step Etching Instrument, Robert L. Crandall Jan 1990

Design And Construction Of A Step Etching Instrument, Robert L. Crandall

Journal of the Microelectronic Engineering Conference

An instrument was designed and constructed to perform a sequential etch of an oxidized silicon wafer by periodically lowering the wafer deeper into an etch bath. The unit will step the wafer at four different time intervals 15, 30, 45 and 60 seconds. Either five or ten steps can be done at one time. The unit is primarily designed for the etching of silicon dioxide in a Buffered Oxide Etch.


Investigation Of Process Induced Defects Using A Lto Process, Joseph Desantis Jan 1990

Investigation Of Process Induced Defects Using A Lto Process, Joseph Desantis

Journal of the Microelectronic Engineering Conference

The effects of process induced defects, such as dislocations and/or oxide induced stacking faults, were investigated for a bipolar process employing solid diffusion sources. Carborundum BN975 Boron Sources have a low temperature oxide (LTD) step to minimize defects. Two bipolar processes, one with and one without LTD were run and electrical tests done to evaluate device characteristics. ~t this point results were inconclusive.


Polysilicon Vs. Aluminum Gate Pmos Ring Oscillators, Kurt E. Gerber Jan 1990

Polysilicon Vs. Aluminum Gate Pmos Ring Oscillators, Kurt E. Gerber

Journal of the Microelectronic Engineering Conference

A nine stage PMOS ring oscillator was designed using polysilicon gates for a self-aligning process while another was designed using a standard metal gate process. A comparison of the polysilicon and metal gate PMQS processes was planned to show the reduced gate capacitance of the self-aligning process. This reduced gate capacitance was to be observed by measuring and comparing the propagation delay of each design on the oscilloscope.


A Diagnostic Test Chip For Nmos Processing, William Gross Jan 1990

A Diagnostic Test Chip For Nmos Processing, William Gross

Journal of the Microelectronic Engineering Conference

Novel test chip structures isolating process problems in certain device regions were designed in area ratios of lx,4x, and 16x in order to investigate sizing trends. The upper three levels of an NMOS process (poly, dielectric, and metal) were fabricated. Metal line integrity structures were tested on a pass or fail basis. Results show that problems did occur in the metal patterning steps causing shorts between adjacent lines. The actual processing steps (photolithography or etching) that were responsible could not be determined without much further testing.


Design And Construction Of A Noncontact Resistivity Measurement Instrument, William R. Hamilton Jan 1990

Design And Construction Of A Noncontact Resistivity Measurement Instrument, William R. Hamilton

Journal of the Microelectronic Engineering Conference

An Eddy—Current Gauge was fabricated from the design of G. L. Miller, D. A. H. Robinson and T. D. Wiley Cl]. The electronics involved was mounted on a printed circuit board and the header assembly was successfully machined and housed in Lucite. The calibration and testing confirmed the instrument’s linear properties for measuring conductivity.


The Impact Of Submicron 10x Reticle Defects On Images Printed With A 0.28 Na G-Line Stepper, Karl D. Hirschman Jan 1990

The Impact Of Submicron 10x Reticle Defects On Images Printed With A 0.28 Na G-Line Stepper, Karl D. Hirschman

Journal of the Microelectronic Engineering Conference

A lOX reticle was produced with programmed defects of both polarities varying size, proximity to adjacent features, and feature sizes. The defects were imaged in various resist materials over silicon, silicon dioxide, silicon nitride, polysilicon, aluminum, and a 1X chrome mask using a GCA/Mann 4800 stepper. Results obtained using optical and scanning electron microscopy demonstrated that reticle defects as small as 1.0 micron, when in proximity to a feature, will cause linewidth variation in the printed image. The resist film and underlying substrate did affect the linewidth variation. Defocus and over/under exposure also influenced the severity of damage created by …


Capacitance-Voltage Characterization For Polysilicon Gate Mos Capacitors, Brian Izzio Jan 1990

Capacitance-Voltage Characterization For Polysilicon Gate Mos Capacitors, Brian Izzio

Journal of the Microelectronic Engineering Conference

The effects of an n-type and p-type doped polysilicon gate fabricated over both an n-type and p-type substrate for MOS capacitors with different polysilicon doping processing schemes was evaluated and compared to the current RIT process that utilizes a metal gate. Both boron and phosphorous Spin on dopants were used to supply the conduction for the gate region of the polysilicon capacitors. Bias temperature bias was performed to evaluate the mobile ion contamination non-ideality, while a FORTRAN program was written to extract important capacitance voltage parameters from the actual C-V plots obtained that are of interest for MOS technologies


The Affects Of High Temperature Steps On Bow, Warp And Slip Of A Wafer, Mark Klare Jan 1990

The Affects Of High Temperature Steps On Bow, Warp And Slip Of A Wafer, Mark Klare

Journal of the Microelectronic Engineering Conference

Bow, Warp and Slip measurements were used to characterize push/pull rates of a three inch oxidation furnace. The push/pull rates were varied from 3 to 30 inches per minute. To minimize the amount of bow, warp, and slip while still being time efficient, recommended push rates of 12 and pull rates of 3 in/mm should were found.


Performing C-T Measurements, James Krawiecki Jan 1990

Performing C-T Measurements, James Krawiecki

Journal of the Microelectronic Engineering Conference

An IBM computer, a HP4145B parametric analyzer, a Micromanipulator 410 capacitance meter, and a Keithley 230 voltage source were networked together to form a test setup to measure the recombination and generation lifetimes of minority carriers. The Zerbst relationships were used to calculate lifetimes. Results indicate that the test setup~has the ability to take accurate data, but when the capacitance-time data was analyzed, the calculated lifetimes were not believable. The problem seems to be the quality of the fabricated capacitors and not the setup.


Processing Techniques Of Mos Capacitors, Michael D. Buczkowski Jan 1990

Processing Techniques Of Mos Capacitors, Michael D. Buczkowski

Journal of the Microelectronic Engineering Conference

Variations in both MOS capacitor structure and fabrication process were characterized using 1MHz C-V measurements. This involved processing MOS capacitors with and without backside oxide, and wet etching versus plasma ashing photoresist. The experimental results show large flatband shifts in wafers that were plasma ashed. ~ longer than expected anneal was utilized to reduce the C-V shifts caused by positive charge build-up in the oxide. The backside oxide did not grossly affect the capacitance measurements.


Studies Of Chlorinated Oxides, Jeffrey J. Ballak Jan 1990

Studies Of Chlorinated Oxides, Jeffrey J. Ballak

Journal of the Microelectronic Engineering Conference

Three oxidation processes were employed to study the effects of chlorine on growth rate and device characteristics of capacitors. Oxide was grown without the use of TCA, with TCA prior to growth, and TCA during growth. An increased growth rate of the oxide, 450 angstroms in 42 minutes with TCA, as opposed to 50 minutes without TCA, was observed. Contrary to what was expected, the TCA processed oxides larger flatband shifts than the standard oxide growth wafers.