Center m Electronics m

Electrical Enciheerihc

Technical Progress Bulletin

US DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Electronics and Electrical Engineering

COVERING CENTER PROGRAMS, OCTOBER 1982 - DECEMBER 1982

July 1983

QC"

100

,1106

33- 2719-3

1933

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATiONAL BUREAU OF STANDARDS. Ernest AmbUr. Director
National bureau

fi£ STANDARDS X LIBRARY 'Ref

QC INTRODUCING THE CEEE TECHNICAL PROGRESS DULLETIN

This Issue marks the Introduction of a quarterly abstract journal covering the work

of the National Bureau of Standards Center for Electronics and Electrical

Engineering. It provides abstracts of papers approved for publication by NBS for the

first quarter of Federal fiscal year 1983 (October through December, 1982). The

abstracts are arranged by technical topic as Identified In the table of contents and

alphabetically by first author within each topic. Also listed are abstracts for

papers published during the quarter. In the future, citations will provide

identification of the Issue of the Technical Progress Bulletin In which the

associated abstract appeared. These citations will also be arranged alphabetically

by first author. In addition to abstracts, Information Is provided, If applicable,

on conference and workshop proceedings; sped al -format publications, such as magnetic data tapes and videotapes; new measurement services, Including calibration

services and standard reference materials; and a six-month calendar of Center events.

Center for Electronics and Electrical Engineering Center programs provide national

reference standa rds , measurement methods , supporting theory and data, and

traceability to national standards.

The metrological products of these programs aid economic growth by promoting equity

and efficiency In the marketplace, by removing metrological barriers to Improved

productivity and Innovation, by Increasing U. S. competitiveness In International

markets through facilitation of compliance with International agreements, and by

providing technical bases for the development of voluntary standards for domestic and

International trade. These metrological products also aid In the development of

rational regulatory policy and promote efficient functioning of technical programs of

the Government.

The work of the Center Is divided Into two major programs: the Semiconductor

Technology Program, carried out by the Semiconductor Materials and Processes and

Semiconductor Devices and Circuits Divisions In Gaithersburg, MD, and the Signals and

Systems Metrology Program, carried out by the Electrosystems Division in Gaithersburg

and the Electromagnetic Fields and Electromagnetic Technology Divisions In Boulder,

CO. Names and telephone numbers of key contacts in the Center are given on the back

cover; readers are encouraged to contact any of these individuals for further

information.

Previous special issues: Two special issues of the Technical Progress Bulletin have

been published with abstracts for the Signals and Systems Program only, NBS I R 83-

2719-1, covering October 1981 through March 1982 and NBSIR 83-2719-2, covering April

1982 through September 1982. NBSIR 82-2636, a special Issue of the Semiconductor

Technology Program Progress Briefs published in January 1983, listed abstracts of

publications from that Program for Federal fiscal year 1982 (October 1981 through

September 1982, fifty-third through fifty-seventh quarters of the Program). The new

C EEE Technical Progress Bulletin replaces the Progress Briefs series [single copies

of 82-2636 are available from the Center, see back cover for address].

P ubl 1 cation 1 ists

:

Guides to earlier as well as recent work are the publications

Ti sts coverl ng TFTe work of each division. These are revised and reissued on an approximately annual basis and are available from the originating division [the

publications from the Semiconductor Technology Program are covered in a single list,

available from either division].

Center sponsors: The Center Programs are sponsored by the National Bureau of

Standards and a number of other organi zati ons , in both the Federal and private

sectors; these are identified on page 22.
CEEE Technical Progress Bulletin - July 83 Page 1

TABLE OF CONTENTS

INTRODUCTION

SEMICONDUCTOR TECHNOLOGY PROGRAM

Silicon Materials

Insulators and Interfaces

Dimensional Metrology

Integrated Circuit Test Structures ....

Process & Device Modeling

Radiation Effects

Packaging

Other Semiconductor Topics

SIGNALS AND SYSTEMS METROLOGY PROGRAM

FAST SIGNAL ACQUISTION, PROCESSING, & TRANSMISSION

inside front cover

2

3

3

5

6

78

10

11

Waveform Metrology

Cryoelectronic Metrology

Antenna Metrology

Noise Metrology

Laser Metrology

Optical Fiber Metrology

Other Fast Signal Topics

ELECTRICAL SYSTEMS

Power Systems Metrology

Superconductors

ELECTROMAGNETIC INTERFERENCE

CEEE CALENDAR

SPONSOR LIST

KEY CONTACTS IN CENTER, CENTER ORGANIZATION

. . 11

. . 11

. . 13

. . 14

. . 14

. . 15

. . 15

. . 16

. . 16

. . 17

. . 20

. . 21

. . 22

back cover
Page 2 CEEE Technical Progress Bulletin - July 83

SEMICONDUCTOR TECHNOLOGY PROGRAM

Silicon Materials

Released for Publication

Baghdadi, A., Multiple Reflection

Corrections In Fourier Transform

Spectroscopy of Back Surface Damaged

Wafers, submitted to Electrochemical

Society Extended Abstracts.

In order to account properly for multiple passes of the infrared beam in backsurface damaged wafers in infrared spectrometers, the effective reflectivity of

the back surface must be measured. Two

methods for accomplishing this are evaluated in a comparative study. The first

method is based upon an analysis of the

spectrum and the second method is based

upon an analysis of the

i nterferogram. [(301) 921-3625]

Forman, R. A., Bell, M. I., Baghdadi,

A., and Mayo, S. , The Effects of

Striations on the Compositional

Analysis of Silicon Crystals,

submitted to Electrochemical Society

Extended Abstracts.

Periodic variations of composition along

the growth direction in semiconductor

crystals commonly arise from fluctuations in the local growth rate. These

striations of impurity content can lead

to systematic errors in compositional

analysis by optical transmission or surface analysis techniques. A model

appropriate for the analysis of such

measurements is presented and estimates

of probable errors are given. The model

is applied to earlier published measurements on the carbon and oxygen content

of silicon. The implications of these

results for studies of intrinsic getteri ng are discussed. [(301) 921-3625]

Phillips, W.E., Thurber, W.R., and

Lowney, J.R., Improved Analysis

Procedures for Deep-Level Measurements

by Transient Capacitance,

submitted to El ectrochemi cal Society

Extended Abstracts.

The procedures reported here provide a way to analyze data from nonexponential

transient capacitance measurements made

under conditions such that (a) the traps are charged in only a part of the depletion layer or (b) the trap density is

not small compared with the net shallow

dopant density. This analysis requires

C-^-vs.-V data to be linear over the

voltage range used, which may be a small

range at low temperatures because of the

compensation effect of traps. Computer

simulations of C- 2 -vs.-V plots are given

for various ratios of trap and dopant

densities at several temperatures and

show ranges which are sufficiently

linear, but which have a trap-densitydependent slope. These effects are illustrated by experimental C- 2 -vs.-V,

isothermal transient capacitance

(ITCAP), and DLTS measurements for a wide range of densities of platinum in

p + n and n+p silicon diodes.

[(301) 921-3625]

Recently Published

Albers, J., Spreading Resistance

Probe-Spacing Experiment Simulations:

Effects of Probe-Current Density and

Layer Thickness, J. Electrochemical

Society 129, pp. 2788-2795 (December

1982).

Model spreading resistance data were calculated using three forms of the

probe-current density: the original

Schumann and Gardner version, the Choo

uniform current density, and the ring

delta function current density in order

to determine whether probe-spacing ex- periment simulations are sensitive to

the specific form of the probe-current

density. Further, since the probes of

the spreading resistance and of the

four-probe sheet resistance apparatus

view the material as a continuum, the

dependence of the results of the probespacing simulation on the number of

layers used in the calculation was also

investigated. From the analysis, it is

possible to conclude, aside from the
CEEE Technical Progress Bulletin - July 83 Page 3

Silicon Materials , cont'd.

differences in the interpreted radii,

that the results of the probe-spacing

simulations in the surface region are

not particularly sensitive to the choice

of either the current density or the

number of layers used in the simulation

(provided, of course, that the number of

layers is of reasonable size to be representative of the continuous nature of

the underlying resistivity). The fail- ure of the probe-spacing experiment

simulation to obtain the correct surface

sheet resistance for the case of a lightly to moderately doped layer over a substrate of the same conductivity type

is not changed by either the probecurrent density or the discrete layer

nature of the calculations used to generate the data. The variable which has

the strongest influence on the outcome

of the probe-spacing experiment is the

substrate resistivity. Hence, for

junction-isolated layers and for heavily

doped layers over substrates of the same conductivity type, probe-spacing experiments will yield the correct sheet re- sistance in the surface region.

[(301) 921-3621]

Thurber, W. R., Forman, R. A., and

Phillips, W. E., A Novel Method to

Detect Nonexponential Transients in

DLTS, J. Appl . Phys. 53, pp. 7397-

7400 (November 1982).

In conventional DLTS measurements, the

analysis of the results is based upon

the assumption of an exponential current

or capacitance transient. We present

experimental and computational results

on a novel experimental method for

determining when the assumption of

exponential ity is not satisfied by the

sample under study. The measurement may

be performed without any changes in the

conventional doubl e-boxcar DLTS system.

[(301) 921-3625]

Insulators and Interfaces

Recently Published

Chandler-Horowitz, D. , El 1 ipsometric

Accuracy and the Principal Angle of

Incidence, Proc. Soc. Photo-Optical

Instrumentation Engineers 342,

Integrated Circuit Metrology, pp. 121-

130 (October 1982).

The effects of improving the accuracy

of the angle of incidence on the

ell ipsometric determination of thickness

and refractive index of oxide and

nitride films on a silicon substrate are analyzed. It is found that the accuracy

of a determination of a film's parameters, thickness and refractive index,

depends as much or more on the accuracy

of the angle of incidence measurement as on the accuracy of the measurement of

the ellipsometric angles A and ip. If

measurements of A and are made close

to the principal angle of incidence, the

accuracy of the determined film parameters can be improved by measuring the

incident angle to an accuracy better

than A and \J>. This is especially true

for thin films of oxide less than a few

tens of nanometers. Because of the

higher refractive index of silicon

nitride relative to silicon dioxide, a nitride film's thickness can be

determined more accurately than an oxide

film's thickness. Therefore, silicon

nitride may make a good candidate film

for a standard thickness sample.

[(301) 921-3625]

Dimensional Metrology

Recently Published

Jerke, J. M. , and Wendell, C. E. , Use

of the National Bureau of Standards

(NBS) Antireflective (AR)-Chromi urn Optical Linewidth Standard for Measurements on Other Types of Chromium Photomasks, Proc. Soc. Photo-Optical

Instrumentation Engineers 342,

Integrated Circuit Metrology, pp. 15-26

(October 1982).

Both antireflective ( AR)-chromi urn and

bri ght-chromi urn photomasks are currently

used in the production of integrated
Page 4 CEEE Technical Progress Bulletin - July 83

Dimensional Metrology , cont'd.

circuits. Differences in the optical

transmittance and reflectance of these

photomasks can significantly change the

line-image threshold required for accu- rate edge detection in optical microscope linewidtn measurements. The

suitability of using a calibration curve based on an AR-chromium optical

1 i newidth-measurement standard (SRM 474)

from the National Bureau of Standards

(NBS) to correct linewidth measurements

on other types of photomasks is discussed. Linewidths on each of three

chromium photomasks of different chromium thicknesses were measured on four

different types of optical microscope

linewidth measurement systems. These

measurements were corrected using an SRM

474 and compared with measurements made

on the NBS optical linewidth calibration

system. For the two bri ght-chromi urn specimens with low transmittance, the

residual differences between the cor- rected values and the NBS values as measured on the NBS calibration system

are generally less than ±0.05 urn for

three of the measurement systems. For

the see-through AR-chromium photomask

with a higher transmittance, the calibration curve does not correct all systematic errors greater than ±0.05 urn. These results support theoretical studies showing that the degree of correction for systematic linewidth errors varies with the transmittance of the

chromium photomask being measured and

with the measurement system.

[( 301 ) 921 - 3786 ]

Jerke, J. M. , Croarkin, M. C., and

Varner, R. N., Semiconductor

Measurement Technology: Interlaboratory Study on Linewidth Measurements

''or Anti reflective Chromium Photomasks,

NBS special Publication 400-74

(Novem;. r 1982).

Optical nicroscopes fitted with a mi

.rometei attachment are commonly used to

measure small linewidths and other critical dimensions on integrated-circuit

( IC) photomasks. In the absence of

calibrated linewidth standards, users have experienced systematic measurement

errors much larger than required manu- facturing tolerances. As IC linewidths

approach 1 ym with a 10 percent tolerance, the need for calibration standards

and improved measurement procedures

becomes even more important.

This report discusses the results of an interlaboratory study to evaluate a National Bureau of Standards (NBS) prototype calibration standard for linewidth measurements on IC photomasks and

procedures for adjusting and calibrating

optical-microscope systems in the 0.5-

to 12-ym measurement range. Using procedures furnished by NBS, industrial

participants measured line spacings and

linewidths on NBS anti ref 1 ecti vechromium artifacts. A comparison of NBS

linewidth values with participants'

measurements showed that most differences were less than ±0.3 urn. A linewidth calibration significantly reduced

systematic errors for most systems.

Outliers in the data showed the need for

measurement-control procedures. The

standard deviation of the measurement

process was ±0.1 ym or larger for about

half of the systems. For some systems,

there were significant day-to-day differences and operator differences.

The study showed that the NBS artifact

and recommended procedures were adequate

for calibrating an opti cal -mi croscope

system which was in a state of statistical control. This study led to the

issuance of NBS Standard Reference Material 474 (Optical Microscope LinewidthMeasureinent Standard). [(301) 921-3786]

Nyyssonen, D. , Theory of Optical Edge

Detection and Imaging of Thick Layers,

J. Optical Society America 72, pp.

1425-1436 (October 1982).

The optical microscope measurement of

small objects, 0.5 to 10 ym, is complicated by the apparent change in the

dimension of the object with a change in

the spatial coherence of the illumination. Coherent edge detection methods
CEEE Technical Progress Bulletin - July 83 Page 5

Dimensional Metrology , cont'd.

have been developed for the measurement

of line objects on integrated-circuit

photomasks and wafers. This paper presents a generalization of the coherent

threshold equation which allows the

extension to any state of partial coher- ence of the illumination as well as extension to the measurement of nonplanar objects. In the latter case, a waveguide model is developed for imaging

of lines patterned in thick layers and

is compared with experimental data.

[(301) 921-3786]

Nyyssonen, D. , Design of an Optical

Linewidth Standard Reference Material

for Wafers, Proc. Soc. Photo-Optical

Instrumentation Engineers 342,

Integrated Circuit Metrology, pp. 27-

34 (October 1982).

Optical linewidth measurements on patterned wafers are complicated by the

wide variety of materials and corre- spondingly wide variation in optical

parameters, complex refractive index and

thickness, used in the manufacture of

integrated circuits. It has been shown

that in addition to linewidth, two key

parameters, the normalized local reflectance R and the optical phase difference

<f> at the line edge, determine the characteristics of the optical image and,

therefore, affect the accuracy and precision of linewidth measurements. Both

of these parameters, R and <|>, are dependent upon the illuminating wavelength or spectral bandpass and the coherence

parameter of the optical system. To

achieve the measurement precision and

accuracy required for VLSI dimensions

(e.g., 10% tolerance for 1-ym linewidths), it is necessary to control

coherence, spectral bandpass, and image

integrity as well as to achieve reproducible edge detection and focus criteria. When a system can be operated

without further operator intervention

despite changes in the materials being

measured, it is possible to calibrate

the linewidth measurement system using a standard fabricated from only a few

materials representing a range of image

characteristics. The desirable characteristics of such a standard are discussed with respect to durability, edge

definition, and equivalence of the image

characteristics to materials used in the

manufacture of ICs. A prototype design

consisting of combinations of SiO? and

chromium layers on a silicon substrate

is presented. [(301) 921-3786]

Integrated Circuit Test Structures

Recently Published

Buehler, M. G. , and Linholm, L. W.

,

The Role of Test Chips In Coordinating

Logic and Circuit Design and Layout

Aids for VLSI, Proc. 2d California

Technical Conf. on VLSI, Pasadena, CA,

January 19-21, 1981, pp. 135-151.

This paper emphasizes the need for multipurpose test chips and comprehensive

procedures for use in supplying accurate

input data to both logic and circuit

simulators and chip layout aids. It is

shown that the location of test structures within test chips is critical in

obtaining representative data, because

geometrical distortions introduced during the photomasking process can lead to

significant intrachip parameter variations. In order to transfer test chip

designs quickly, accurately, and economically, a commonly accepted portable

chip layout notation and commonly ac- cepted parametric tester language are needed. In order to measure test chips

more accurately and more rapidly, parametric testers with improved architecture need to be developed in conjunction

with innovative test structures with on- chip signal conditioning. [Contact:

Linholm, (301) 921-3541]

Proctor, S. J. , and Linholm, L. W. , A

Direct Measurement of Interfacial Contact Resistance, IEEE Electron Devices Letters EDL-3, 294-296 (October

1982).

A method is described for directly measuring interfacial contact resistance
Page 6

Integrated Circuit Test Struct . , cont ' d

.

CEEE Technical Progress Bulletin - July 83

and estimating the degree of uniformity

of the interfacial layer in metalsemiconductor contacts. A twodimensional resistor network model is

used to obtain a relationship between

the specific contact resistance and the

measured interfacial contact resistance

for contacts with a homogeneous interfacial layer. Measurement results are given for 98.5 percent Al/1.5 percent Si

and 100 percent A1 contacts on n-type

silicon. [Contact: Linholm, (301)

921-3541]

Yen, D., Electrical Test Methods for

Evaluating Lithographic Processes and

Equipment, Proc. Society PhotoOptical Instrumentation Engrs. 342,

Integrated Circuit Metrology, pp. 73-81

(October 1982).

A test structure is a microelectronic

device that is fabricated by the same process used to fabricate integrated

circuits (ICs) and can be tested electrically to determine important process

parameters. Test structures can be used

to evaluate semiconductor materials,

evaluate and control process uniformity,

measure device and circuit parameters,

obtain input parameters for circuit

simulation programs, and determine the

performance of processing equipment.

This paper reviews previous work at NBS on the design, measurement, and application of two types of test structures

that have been used for evaluating

lithographic processes and lithographic

equipment performance. First, the

cross-bridge sheet-resistor test structure is described. Test results from

electrical measurements on this structure can be used to determine the electrical linewidth of a conducting layer.

The use of test chips containing arrays

of identical cross bridges for determining the uniformity of a lithographic

process will be described. Analysis of

test results from these arrays has been

used to identify and separate the con- tribution to linewidth nonuniformities

introduced by individual equipment and

processes. The precision to which linewidth can be determined using this

structure will be discussed. Also, an electrical alignment test structure for

determining the misalignment between two

photomask steps will be described and an example of its use presented. Finally,

an automated dc parametric test system

used for measuring these structures will

be described. [(301) 921-3621]

Yen, D. , Linholm, L. W., and Buehler, M.

G. , A Cross-Bridge Test Structure for

Evalatlng the Linewidth Uniformity of an Integrated Circuit Lithography

System, J. Electrochemical Society

129, pp. 2313-2318 (October 1982).

This paper describes an electrical mea- surement method using a cross-bridge

test structure to evaluate linewidth

variations associated with integrated

circuit lithography. Arrays of cross- bridge test structures are used to measure the uniformity of linewidth across

a wafer. Utilizing this test structure

array and high speed electrical test

methods, sufficient quantities of data are obtained to make statistical comparisons and to evaluate a step-and-repeat

system used to fabricate photomasks.

The measured variation in linewidth,

which was systematic and repetitive from

sample to sample, was several tenths of

a micrometer across a wafer and within a chip. This within-chip variation should

be of special concern in the fabrication

of devices that are sensitive to linewidth dimensions (i.e., MOSFETs with

short channel lengths). The linewidth

measurement precision using the cross- bridge test structure was shown to be

0.03 urn (la). [(301) 921-3621]

Process & Device Modeling

Released for Publication

Bennett, H.S., Improved Device Physics

for Calculating the Gain of Bipolar

Structures In Silicon, submitted

to Proc. Workshop on Submicron

Physics.
CEEE Technical Progress Bulletin - July 83 Page 7

Process & Device Modeling , cont'd.

A model which is more physically correct

than the extension of the empirical

procedures of Slotboom and de Graaff for

donor densities above 2.5 x 10 19 cm

-3

has been developed for the effective

intrinsic carrier concentration n-j e in n-type silicon. This new approach,

which is based upon quantum mechanics

and optical measurements for the bandgap, has been applied to an npn

transistor with a 1-ym emitter-base

junction depth and with donor densities

greater than 102 ° cm-3

. Conventional

device physics with even unrealistic

carrier lifetimes does not predict the

measured dc common emitter gain. The

approach described here with carrier

lifetimes comparable to those expected

in processed silicon (~0.1 us) does

predict the gain correctly.

[(301) 921-3541]

Lowney, J. R., and Bennett, H. S.,

Effect of Ionized Donors on the

Electron and Hole Densities of States

in Silicon, submitted to J. Applied

Physics.

A self-consistent second Born approximation has been used to calculate the

change in the electron and hole densities of states due to ionized donors in

silicon. The results are compared with

a previous partial-wave technique and

found to be in good agreement for a case

of common applicability, i.e., a donor

density of 102 ° cm

-3 at room temperature. [(301) 921-3625]

Radiation Effects

Recently Published

Blackburn, D. L. , Berning, D. W. , Benedetto, J. M., and Galloway, K. F.,

Ionizing Radiation Effects on Power

MOSFETs During High Speed Switching,

IEEE Trans. Nucl. Sci. NS-29, 1555-1558

(December 1982).

Data on the effects of gamma radiation

on the electrical characteristics of

power VDMOS transistors are presented.

The devices were exposed to radiation

while the gate voltage was switching at

100 kHz or while held at a dc voltage.

Several drain voltage configurations

were also explored. The threshold voltage shifts observed begin to saturate at

relatively low doses (~0.1 Mrad(Si)) for

all but the worst case bias (Vq = +10

V). The threshold voltage shifts do not

show significant dependence on drain

voltage. The devices studied appear to

be approximately an order of magnitude

more efficient in trapping radiation

generated holes than would be expected

in a state-of-the-art radiation hardened

planar M0SFET. [(301) 921-3541]

Wilson, C. L., and Blue, J. L.,

Modeling of Ionizing Radiation

Effects in Short-Channel MOSFETs,

IEEE Trans. Nuclear Science NS-29,

1676-1680 (December 1982).

The effect of ionizing radiation on short-channel MOSFETs is modeled using a charge-sheet approach. The primary effect of ionizing radiation is the introduction of oxide trapped charge (0TC)

and interface trapped charge ( ITC)

.

Using a two-dimensional charge-sheet

model, transistors with channel lengths

between 4.65 urn and 0.27 ym were

studied. A range of net 0TC and ITC

values of ±4.0 x 10 11 cm

-2 was used to

study dose effects corresponding to 10 6 rad(Si02

).

ITC and 0TC cause significant effects in

each region of operation. In the subthreshold region, the sensitivity of

drain current to these charges is exponential. A more realistic model must

include the energy distribution of the

ITC charge as well as two-dimensional

charge sharing effects. In the triode

region, the effects of ITC and 0TC are indistinguishable from two-dimensional

charge sharing effects. This implies

that a simple analysis of threshold

voltage offsets in short-channel MOSFETs

is incapable of providing a physically

meaning separation of two-dimensional

effects from radiation-induced effects.
Page 8 CEEE Technical Progress Bulletin - July 83

Radiation Effects , cont'd.

In the saturation region, the combined

OTC and ITC contribute a fixed charge

component to the channel charge which

can shift the critical field point at

the edge of the pinch-off region in the

channel. This critical field effect

alters the formation of the "knee" re- gion of the output characteristic and can alter the output conductance in the

saturation region for short-channel

transistors. [(301) 921-3541]

Packaging

Recently Published

Harman, G.G., and Harmison, K.A., The

Assessment of Hybrid Package GlassMetal Seal Reliability Using Acoustic

Emission Measurement Techniques, International J. Hybrid

Microelectronics, 5, pp. 248-259

(November 1982).

Experiments were conducted to assess

potential reliability hazards to hybrid

package glass-metal seals that may be

encountered during hybrid assembly, or later in an avionics vibration environment, and to devise tests to reveal

potential failures. The effects of an avionics vibration environment on the

seals of PC-board-mounted hybrids were determined. In general, for flatpack

type packages, lead fatigue failure

occurs before seal damage to packages

from high quality lots. Plug-in-type

packages that were soldered into platedthrough holes on PC boards appeared to

be immune to vibration-induced seal

damage and served as board stiffeners.

An acoustic-emission (AE) monitored

hot-stage shock test was developed that

detects weak package seals either at the

manufacturer* s facility or on incoming

inspection. The stresses that are applied to the internal extension of a package lead during bonding were

monitored with AE, and "loose particles"

of glass were found to crack off if the

glass meniscus extended significantly

under the lead.

General conclusions of this study are that glass-metal seals in hybrid

packages from high quality lots are very

reliable even when subject to high

thermal or mechanical stresses.

However, the seals from packages

"screened as good" from reject or poor

quality lots are more subject to

hermetic failure under the low to

moderate stresses that may be

encountered in handling or assembly. In addition, there is little correlation

between visual inspection failures of

glass seals and their hermeticity.

[(301) 921-3621]

Harman, G. G. , Acoustic-EmissionMonitored Tests for TAB Inner Lead Bond

Quality, IEEE Trans. Components,

Hybrids, and Manufacturing Technology

CHMT-5, pp. 445-453 (December 1982).

This paper gives a brief introduction to

acoustic-emission (AE) based tests

applied to quality control in the

electronics industry and describes some recent research on this testing

technique. Equipment and circuits are described that may be used to implement

such AE-monitored testing. Acousticemission-monitored test systems to

determine the inner lead bond quality

for Tape Automated Bonding (TAB) have

been developed. These include a pull

tester and a microfatigue tester for

off-line evaluation of bond quality and

metallurgical system reliability as well

as an automatic on-line production bond

quality tester. The microfatigue tester

for TAB leads can apply a small

oscillatory (up to 80 Hz) force on top

of a constant force bias of a few grams.

A major result of such fatigue tests was to show that the most common

metallurgical system (tin-plated copper

leads bonded to gold bumps) results in

the formation of brittle intermetallic

compounds which crack easily. The

cracks propagate under cyclic stress and

result in a very low fatigue life,

compared to another TAB metallurgical

system. The acoustic-emission-monitored

inner lead bond integrity tester and

lead-forming system is designed to be
CEEE Technical Progress Bulletin - July 83 Page 9

Packaging , cont'd.

used on-line. Precision wedge-shaped

tools rise up from below a clamped chip

and apply a predetermined force (~100

mN) to the leads, which both

nondestructively tests the bonds and

forms the leads. If any lead separates,

or partially separates from the bump, or the bump separates from the chip, the

acoustic emission monitor can indicate

failure and the device can be rejected.

Data are presented to show various

failure modes of the TAB system.

[(301) 921-3621]

Ruthberg, S., Leak Testing of

Hermetically Sealed Electronic

Components, Proc. Qualtest I,

American Society for Nondestructive

Testing, Pittsburgh, PA., October 4-7,

1982, pp. 431-436.

In the electronics industry the

requirements are for leak testing large

numbers of relatively small sealed

packages to very fine leak rates. A

wide variety of package materials are used; internal volumes range from less

than 10- 3 cm 3 to greater than 10 cm 3

; and the leak size reject level may be

less than 1 x io- 9 Pa*m3 /s. No single

test can cover the leak size range.

Present preferred methods such as the

radioisotope, helium leak detector, and

others are assessed as to range,

recision, efficiency, and usefulness as ased upon fluid transport mechanisms

and experimental data.

[(301) 921-3625]

Ruthberg, S., Hermetic Testing of

Large Hybrid Packages, International

J. Hybrid Microelectronics 5, pp. 215-

232 (November 1982).

Hermetic testing is a routine operation

in the microelectronics industry with

millions of packages being screened each

year. The technical literature contains

numerous manuscripts on the subject.

Test procedures are set forth in MIL-STD

883, in MIL-STD 750, in NASA

Certification requirements, in ASTM

standards, and in other documents. Yet

disagreements in test results between

supplier and user are common, different

test methods provide different results

for the same leak range on the same parts, results are dependent on package

configuration, and the specified reject

limits as set forth in the standards are somewhat arbitrary. Many of these

problems can be understood by

consideration of the gas transport

mechanisms and of the different flow

models selected for the various test

methods. The greater internal free

volume and the increased configuration

complexity of the large hybrid package

introduce additional constraints. The

leak rate reject level for the larger

package is considered from the viewpoint

of moisture infusion rates, and their

impact on test parameters is examined.

Range, efficiency, and usefulness are examined for such popular test

procedures as the helium leak detector,

radioisotope, weight gain, and bubble

methods as well as for others such as the tracer probe, differential pressure,

and rapid cycle methods that are more

appropriate for the larger package. The

issues described above are discussed

with the aid of graphical solutions and

actual test data. [(301) 921-3625]

Ruthberg, S., Semiconductor

Measurement Technology: Graphical

Solution for the Helium Leak Detector

and Radioisotope Methods of Hermetic

Test: Master Graphs and Instructions,

NBS Special Publication 400-73

(November 1982).

A graphical procedure for solution of

the molecular flow approximation for the

back pressurization method of hermetic

test makes use of a set of characteristic curves and a test line. The

characteristic curves are appropriate

for both the helium leak detector and

the radioisotope methods of test,

although the form of the test line

differs between the two methods. Master

graphs of the characteristic curves and

test lines are now provided in a scale

and format appropriate for producing
Page 10 CEEE Technical Progress Bulletin - July 83

Packaging ( cont'd.

suitable worksheets with a copier.

Step-by-step Instructions are given for

their use In obtaining solutions for

various examples relative to the test

specifications In acceptance standards

such as MIL-STD 883B, etc. One set of

characteristics Is provided specifically

for the helium leak detector mode as expressed directly In terms of air leak

rate; a second set Is provided

specifically for the krypton-85

radioisotope mode also in terms of air

leak rate; and a third set Is retained

In the original form for use with any

tracer gas. [(301) 921-3625]

Other Semiconductor Topics

Recently Published

Scace, R.I., The Semiconductor

Equipment and Materials Institute

Specification for Solar Cell Silicon,

Solar Cells 7, pp. 77-78 (1982).

The specification for solar cell silicon

slices under development by the Semiconductor Equipment and Materials Institute

Is described. The specification covers

physical and dimensional but not electrical attributes of the material. Work

to establish standardized dimensions of

slices is continuing. [(301) 921-3786]

Schafft, H.A., Measurements for

Commercial Photovol talcs: A Status

Report, Solar Cells 7, pp. 23-46

(1982).

The first part of this report discusses

how reliable measurements play an important role along the chain of

supplier-user links that make up the

phot ovol t ai cs industry and its

customers. Such measurements provide

accurate information on materials,

fabrication processes, product

characterization and product needs on which sound decisions can be made to

optimize the performance of processes

and products. They are also indispensable for effective communication in the

marketplace. The second part reviews

the results of visits to Industry to

Identify measurements-related Issues

that affect the expeditious development

and application of photovoltalcs. The

results are organized Into nine

categories: (1) silicon characterization; (2) quality assurance; (3)

electrical measurements of solar cells

and modules (Including accuracy and

reproducibility of measurements,

spectral response, reference cells and

simulators and spectra distribution);

(4) solar data; (5) Interactions with

customers; (6) measurement equipment;

(7) module certification; (8) standards;

(9) role of government. The third part

of the report provides an overview of

measurement and standards development

activities. The Intent of this Is to

promote an awareness of such work to

encourage thereby greater participation

and also timely use of the results of

this work. [(301) 921-3621]
CEEE Technical Progress Bulletin - July 83

SIGNALS AND SYSTEMS METROLOGY PROGRAM

FAST SIGNAL ACQUISITION, PROCESSING,

AND TRANSMISSION

Waveform Metrology

Released for Publication

Lawton, R.A., Performance Standards

for Waveform Recorders, submitted

to IEEE Trans, Nuclear Science.

A new technical committee for the Instrumentation and Measurement Society of

the IEEE has been formed and is called

Waveform Measurements and Analysis.

The first task is to develop a performance standard for waveform

recorders to satisfy a growing need for

specifying the performance of the many

new waveform recorders (transient

digitizers, digital oscilloscopes, etc.) now coming on the market.

The work of the committee to date is

described together with the efforts of

the Electromagnetic Waveform Metrology

Group at the National Bureau of Standards in Waveform Standards Development.

[(303 497-3339]

Recently Published

Leedy, T.F., Gans, W.L., Bell, B.A.,

Lederer, P.S., and Nelson, R.E.,

Automatic Test Equipment Calibration/

Performance Verification Evaluation and

Research Program, NBSIR 82-2601

(December 1982).

This work describes an experimental

approach to verify the performance of

selected third generation automatic test

systems. The approach consisted of

careful laboratory characterization of

two types of signal sources. One was a dc and low frequency ac voltage source covering the range of approximately 100

mV to 200 V dc, and 300 mV to 140 V ac rms over a frequency range of 100 Hz to

10 MHz. The second source was a precision time synthesizer used to generate

Page 11

pulses of known durations from 50 to

1000 ns. Both of these sources were used to verify the ability of two automatic test systems to measure ac and dc

voltages and time intervals. The

methods used to characterize these

sources and the measurement results of

applying the sources to the two automatic test systems are discussed in

detail. Recommendations for future

efforts to improve the measurement capabilities and traceability of automatic

test systems are also presented.

[(301) 921-2727]

Schoenwetter, H.K., Sensitive Analog

Comparator, IEEE Trans. Instrumentation & Measurement IM-31, pp. 266-269

(December 1982)

.

A strobed, sensitive analog comparator

has been developed for use in the NBS

Data Converter Test Facility. The

comparator has a sensitivity of 1.5 yV

and a response time of 30 us to within

10 uV, following input steps up to 20 V. Signal voltages up to ±10 V are compared

with reference voltage levels of

opposite polarity, using a precision

resistive divider. The input offset has

a temperature coefficient of -1 uV/°C

and changes less than ±5 yV under worstcase dynamic conditions. Following a strobe pulse, the digital output is

retained until the next strobe pulse.

Optical isolators provide isolation

between the analog and digital circuits.

[(301) 921-2727]

Cryoelectronic Metrology

Released for Publication

Hamilton, C. A., 100 GHz Binary

Counter Using SQUID Flip Flops,

submitted to Proc. Applied Superconductivity Conference.

A binary counter using bistable dc

SQUID'S as flip flop circuits is re- viewed. Its potential for frequency

division in the THz range and for ultra

high accuracy A/D conversion is discussed. [(303) 497-3740]
cont ' d

Page 12

Cryol ect ronl c Metrology ,

Hamilton, C. A., Lloyd, F. L. , 8-B1t

Superconducting A/D Converter,

submitted to Proc. Applied Superconductivity Conference.

The design, fabrication and testing of a superconducting 8-bit converter are presented. Experimental results show

essentially monotonic output code at

conversion rates of a few megahertz. An

algorithm for automatic adjustment and

potential problems of higher speed operation is discussed. [(303) 497-3740]

Kautz, R. L., Chaos in Josephson

Circuits, submitted to Proc. Applied

Superconductivity Conference.

Chaotic behavior in Josephson circuits

Is reviewed using the rf-drlven junction

as an example. Topics Include the

effect of chaos on the I-V characteristic, the period doubling route to chaos,

and power spectra for the chaotic state.

Liapunov exponents and the fractal

geometry of strange attractors are also

discussed. [(303) 497-3391]

Kautz, R. L. , Operation of a Superconducting Analog-to-dlgltal Converter

at Short Conversion Times, submitted

to Proc. Applied Superconductivity

Conference.

The accuracy of a six-bit superconducting analog-to-digital converter has been

tested at short aperture times. The

accuracy was found to be good for

conversion times down to 0.5 ns but

significant errors were observed at a conversion time of 0.1 ns. These errors

can be understood in terms of unwanted

switching events that occur when the

mode boundary separating two flux states

is crossed rapidly.

[( 303 ) 497 - 3391 ]

Muhlfelder, B., Johnson, W. , Cromar,

M. W. , Double Transformer Coupling to

a Very Low Noise SQUID, to be

published in Proc. Applied Superconductivity Conference.

CEEE Technical Progress Bulletin - July 83

We have built and tested a planar dc

SQUID with an Integral matching

transformer. The measured coupling Is

In good agreement with our calculations.

We demonstrate that this configuration

can efficiently couple a 1 pH signal source to a 16 pH SQUID loop. We have

also built an uncoupled SQUID of this

design that has an energy sensitivity,

referred to the SQUID inductor, of 20 h over a flux range of about 0.15 4> 0 . [(303) 497-5375]

Sullivan, D.B., Radebaugh, R., Daney,

D.E., Zimmerman, J.E., An Approach

to Optimization of Low- Power Stirling

Cryocoolers, sumitted to Conf. on Refrigerators for Cryogenic Sensors.

We describe a method for optimizing the

design (shape of the displacer) of

low-power Stirling cryocoolers relative

to the power required to operate the

systems. A variational calculation

which Includes static conduction losses,

shuttle losses, and radiation losses,

together with regenerator Inefficiency,

has been completed for coolers operating

in the 300 K to 10 K range. While the

calculations apply to machines with

tapered displacers, comparison of the

results with stepped-di spl acer

cryocoolers indicates reasonable

agreement. [Contact: Zimmerman, [(303)

497-3901 or -5427] •

Van Zeghbroeck, B. J., A Superconducting Current Injection Transistor,

submitted to Applied Physics Letters.

A new superconducting transistor has

been investigated, both theoretically

and experimentally. The device has a current gain of 10 and an estimated

power-delay product of 90 attojoules.

Possible applications include analog

amplification and digital logic. It is

shown that in principle, the gain of the

device is limited only by its length.

[(303) 497-51 21]

Zimmerman, J.E., Daney, D.E., Sullivan,

D.B., Development of a SecondGeneration Low-Power Stirling
CEEE Technical Progress Bulletin - July 83 Page 13

Cryoelectronic Metrology , cont'd.

Cryocooler, submitted to Proc.

Conf. on Refrigerators for Cryogenic

Sensors.

A very low-power low-interference

Stirling cryocooler is being developed

based on principles and techniques

developed over the last four years and

described in several previous publications. It differs in several important

details from those built previously. It uses a tapered displacer based upon an analytical optimization procedure. The

displacer is driven by an auxiliary

piston and cylinder (rather than by

mechanical linkage) using some of the

working fluid itself to provide the

driving force. This provides smooth,

vibration-free motion, and, more importantly, allows complete mechanical and

spatial separation of the cryostat from

the pressure-wave generator. Either of

two different pressure-wave generators

can be used. One uses a non-contaminating unlubricated ceramic piston and

cylinder. The other uses a compressedair-operated rubber diaphragm and motordriven valves to cycle the pressure

between appropriate limits.

[(303) 497-3901 or -5427]

Recently Published

Hamilton, C.A., 100 GHz Binary Counter

Based on DC SQUIDS, IEEE Electron

Device Letters EDL-3, No. 11, pp. 335-

338 (November 1982)

.

A binary counter using bistable dc

SQUID's as flip flop circuits is demonstrated. All of the functions: LOAD,

COUNT, STORE, READ, and CLEAR can be

performed. The use of single flux quantum logic results in high sensitivity

(1 0- 1

8

J input pulse energy), high speed

(100-GHZ count rate) and low power

(10- 7 W at 100-GHz count rate).

[(303) 497-3740 or 3988]

Antenna Metrology

Hill, D. A., Leaky Feeders and Subsurface Radio Communications,

submitted to IEEE Antennas and Propagation Society Newsletter.

This book review will appear in the IEEE

Antennas and Propagation Society News

letter. It is a summary of the contents

and a technical evaluation of the 1982

book. Leaky Feeders and Subsurface Radio

Communications, by P. Delogne.

[(303) 497-3472]

Recently Published

Baird, R.C., and Estin, A.J., The

Orbiting Standards Package: A Recall* - bratable Satellite Instrument Assembly

for Measuring Large Earth Station Antennas, Proc. Antenna Measurement

Techniques Association, Las Cruces,

NM, October 5-7, 1982, pp. 5. 1-5. 9.

The concept of an Orbiting Standards

Package (0SP) has been discussed as a means of making direct measurements of

fields, patterns, and polarization

states of signals radiated from large

earth station antennas. It would also

have the capability of producing test

fields of known intensities and arbitrary but well-defined polarization

states, thereby enabling the determination of such parameters as G/T and Effective Receiving Area of earth stations. Recent developments in microwave

six-port networks and in standard

antennas would permit the all -electronic

generation and detection of these signals. Moreover, it appears possible to

recalibrate the satellite standards

package to laboratory state-of-the-art

accuracy following launch.

[(303) 497-3301]

FitzGerrell, R. G. , A Partial Loop

Source of E and H Fields for Antenna

Factor Calibration (A Loop Cell),

Proc. Antenna Measurement Techniques

Association, Las Cruces, NM, October 5-

7, 1982, pp. 15.1 - 15.22 [also to be

published in IEEE Trans. Electromagnetic Compatibility].

Released for Publication
Page 14 CEEE Technical Progress Bulletin - July 83

Antenna Metrology , cont'd.

The loop cell is fabricated using two

intersecting metal sheets joined at

the intersection and forming a 36-degree

angle. A section of a loop is mounted

between two coaxial panel jacks, one on each sheet located at a distance equal

to the loop radius from the intersection. A known current through this

section of electrically small loop produces calculable E and H fields between

the sheets in the plane of the loop.

These known fields may be used to determine the antenna factor of small E and H antennas placed in the field if the

mutual impedance due to the antenna

images in the sheets is negligible and

the antenna is not close to the open

edges of the cell. Measured and calculated antenna factors agree within 2 dB

between 0.25 and 1000 MHz. [Contact:

H.E. Taggart, (303) 497-3462]

Repjar, A. G. , Baird, R. C., and Newell,

A. C., Accurate Gain Measurements by

an Extended Version of the NBS

Extrapolation Method, Proc. Antenna

Measurement Techniques Association, Las

Cruces, NM, October 5-7, 1982, pp.

F7-F9.

A General Extrapolation Technique which

eliminates the effects of ground reflections in absolute gain measurements has

been developed. It extends the Extrapolation Method developed at NBS which, in

its present form, utilizes only amplitude versus distance data and a curve fitting procedure to determine gain.

The main advantages of the extrapolation

method are its accuracy and generality,

and there is essentially no upper frequency limit. It can, in principle, be

applied to any type of antenna although

some directivity is desirable to reduce

multipath i nterference. Above 1 GHz

uncertai nties between 0.08 and 0.10 dB

in gain are achieved routinely. Below

1 GHz however, a transfer standard is

often broadbeam and produces ground

reflections which cause oscillations in

the amplitude data as a function of

distance. These oscillations have

longer periods than those due to the

multile reflections between antennas

which are routinely averaged out in the

Extrapolation Method. For this reason,

below 1 GHz and for gains less than

about 10 dB, the antenna might not be

calibratable by the usual Extrapolation

Method, since errors in gain In the

order of 1 to 2 dB could result. Now,

however, by utilizing both amplitude and

phase data as a function of distance,

the extended version of the NBS

extrapolation method can correct for

ground reflections and can be used to

calibrate antennas below 1 GHz.

Uncertainties in gains, typical ly 0.12

dB, are achieved. The method and some results will be presented. [(303) 497-

5703]

Noise Metrology

Released for Publication

Wait, D. F., Earth Terminal Measurement

System Operations Manual (Revised), to

be published as NBSIR 83-1679(R).

The Earth Terminal Measurement System

(ETMS) was developed by the National

Bureau of Standards to make accurate

measurements of earth terminal and sat

ellite parameters such as figure of

merit (G/T), antenna gain relative to a reproducible reference level, the noise

equivalent flux (NEF), and noise

ulterior flux (NUF). This manual

includes the theory of the measurements,

measurement procedures, measurement

trouble shooting, interpretation of the

results, and a discussion of the ETMS

software. [(303) 497-3610]

Laser Metrology

Recently Published

Sanders, A. A., Rasumussen, A. L.,

A System for Measuring Energy and Peak

Power of Low-Level 1.064 ym Laser

Pulses. NBS Tech Note TN-1058,

(October 1982).

For the first time, transfer standards

have been developed for measuring
CEEE Technical Progress Bulletin - July 83 Page 15

Laser Metrology , cont'd.

1.064 ym laser pulses of duration about

10-100 ns, peak irradiance of about

10- 8 -10- 4 W/cm2 and fluences of about

10- 1

6

-10- 11 J/cm 2

. These energy and

power measurement devices use PIN and

APD silicon detectors, respectively, and can be used as stable transfer standards

with total uncertainties (random errors computed at the 95 percent confidence

level) of 10 to 15 percent. The system

for calibrating these transfer standards

is also described and consists of a cw Nd:YAG laser beam acoustoopti cal ly modulated to provide low-level laser pulses

of known peak power and energy. A detailed evaluation of systematic and

random errors is also shown.

[(303) 497-5341]

Optical Fiber Metrology

Released for Publication

Gallawa, R. L. , Chamberlain, G. E., Day,

G. W. , Franzen, D. L. , Young, M.,

Measurement of Multimode Optical Fiber

Attenuation, to be published as NBS

Tech Note TN 1060.

This document is one of a series which

describes optical fiber measurement

capabilities at the National Bureau of

Standards. We concentrate here on the

measurement of attenuation of multimode,

telecommunication-grade fibers in the

wavelength of 850 nm to 1300 nm. The

document begins by discussing the need

for restricted launch conditions, the

most fundamental and crucial aspect of

precise attenuation measurements. The

limited phase space launch and the mode

filter launch are discussed. Attention

then turns to the practical matter of

ensuring that the conditions of the re- stricted launch are met. The question

of guaranteeing system linearity is included. A discussion of system noise is

also included. The document describes

measurement procedure and results obtained in the laboratory using three

typical fibers. Results are presented

for the two wavelengths of current

interest: 850 nm and 1300 nm. The

procedures are applicable to any wavelength, however. The document touches

briefly on the matter of monomode

fibers. Finally, a summary of the

results from an interlaboratory comparison are presented to give perspective to

the stability of a fiber subjected to

handling and shipping. [(303) 497-3761]

Recently Published

Kim, E. M., Franzen, D. L. , An Interlaboratory Measurement Comparison of

Core Diameter on Graded- Index Optical

Fibers, NBS Special Pub. SP-641,

(October 1982)

.

Core diameter is an important geometrical parameter used in fiber specification. Unnecessary splice loss can be

reduced by joining fibers of similar

dimension. A core diameter of 50 ym has

been internationally accepted for multimode graded-index fibers.

[(303) 497-3897 or -5342]

Other Fast Signal Topics

Released for Publication

Young, M., Scratch Standards Should

Not be Used to Predict Damage Threshold, submitted to Proc. Laser Damage

Conference.

The scratch and dig standards are the

most widely used surface quality

standards in the industry. In the

proceedings of the 1980 symposium,

Harold E. Bennett showed theoretically

that damage ought to be initiated near a defect and related damage threshold to

defect size.

Evidently because of one or both of

these facts, some purchasers may use the

scratch standards to specify the surface

quality of components intended for high

power laser systems. Although damage is

often associated with the presence of a defect, this is an inappropriate use of

these purely cosmetic standards. The

classification of a particular scratch
Page 16

Other Fast Signal Topics , cont'd.

correlates only very loosely with its

width or depth. Even if a component is

made of glass, little or nothing

pertinent to damage threshold may be

determined by classifying a scratch

according to the existing cosmetic

standards.

[(303) 497-3223 or -5342]

Young, M., Questions Students Ask,

submitted to The Physics Teacher.

Answer to the question whether the

greenhouse effect is a "hoax," submitted

at the request of the associate editor

of the journal. The greenhouse effect

(radiation trapping) is not a hoax,

although reduced convection plays a major role. [(303) 497-3223 or -5342]

ELECTRICAL SYSTEMS

Power Systems Metrology

Released for Publication

Kotter, F. R., and Smith, A. N. , A

Study of Air-Gap Breakdown at 28.5

Kilohertz, submitted to IEEE Trans.

Power Apparatus & Systems.

Measurements of the electrical breakdown

of both quasi -uni form and highly non- uniform-field air gaps at a frequency of

28.5 kHz are reported. Gaps between a variety of electrode geometries ranged

from a few centimeters to over two

meters in length. Breakdown voltages

significantly below the corresponding

60-Hz values were observed with

electrodes for which appreciable prebreakdown discharges occurred, and a pattern of "anomalous" flashovers at

considerably lower than the normal

breakdown voltages was noted with quasiuniform field gaps. The results

obtained appear to correlate well with

the data found in the literature for

higher frequencies but lower voltages.

[(301) 921-3121]

Mcknight, R. H. , and Kotter, F. R. , A

CEEE Technical Progress Bulletin - July 83

Facility to Produce Uniform Space

Charge for Evaluating Ion Measuring

Instruments, submitted to IEEE Trans.

Power Apparatus & Systems.

A low-speed wind tunnel containing space

charge has been constructed and evaluated. The facility is used for testing

the performance of ion counters and net

space charge measuring devices. For

different operating conditions, space

charge densities in the test volume

range from 2. 5-5. 7 x 10- 8 C/m 3

. The

space charge density is spatially uniform within ±5% over more than 90% of

the cross sectional area of the test

volume, but decreases by approximately

20% between two positions separated by

1 m. Ion densities achieved in this

system are comparable to those found near high-voltage dc transmission lines

but are free from the accompanying large

electric fields. [(301 ) 921-31 21]

Recently Published

Fitzpatrick, G. J. , Forster, E. 0.,

Kelley, E. F., and Hebner, R. E.,

Effects of Chemical Impurities on Prebreakdown Events In Toluene, 1982

Annual Report, Conference on Electrical

Insulation and Dielectric Phenomena,

Amherst, Massachusetts, October 17-21,

1982, pp. 464-472.

Effects of chemical impurities on the

breakdown process in toluene have been

investigated under non-uniform field

conditions using a high-speed image

converter camera. The resistivity of

the four samples investigated ranged

from 10 9 to 10 13 ft*cm. It was noted

that when the cathode was a point,

streamer growth rate increased slightly

with decreasing resistivity. When the

needle was an anode, streamer growth

rate was not measurably affected by

changes in resistivity or applied

voltage, requiring 1.6 ± 0.3 ys to cross the 3 mm gap. Independent of the

polarity of the needle, the last step in

the traverse leading to breakdown of the

gap occurred at speeds greater than 1 x 10 8 cm/s. In purified toluene, more
CEEE Technical Progress Bulletin - July 83 Page 17

Power Systems Metrology , cont'd.

than 200 kV could be applied to a 3 mm

gap without breakdown. With the needle

as a cathode, impurities facilitated the

generation of secondary streamers which

appeared to grow from the primary

bush-like streamers. With decreasing

resistivity, the branching of these

streamers seemed to increase.

[(301) 921-3121]

Hebner, R. E., Development of Power

System Measurements — Quarterly

Report April l, 1982 to June 30, 1982,

NBSIR 82-2586 (October 1982).

This report documents the progress on four technical investigations sponsored

by the Department of Energy and performed by the Electrosystems Division,

the National Bureau of Standards. The

work described covers the period

cables, the characteristics of positive

and negative corona in compressed SF6 gas, and the measurement of the space

charge density in transformer oil

subjected to 60-Hz excitation.

[(301) 921-3121]

Van Brunt, R.J. , Misakian, M., Leep,

D.A., Beaty, E.C., Gallagher, J.W.,

Cooke, C.M., Wyatt, K. , and Gels, R.G.

,

1981 Annual Report: Technical

Assistance for Future Insulation

Systems Research, NBSIR 82-2555

(November 1982).

A system for measuring the electrical

properties of corona pulses has been

characterized and is discussed. Additional data on the pulse height distributions of positive and negative corona

pulses in pure SF

6 for point-plane

electrode geometries are presented.

Basic mechanisms for initiation of

electric discharges in SF6 for highly

nonuniform fields have been investigated

in a collaborative effort between NBS

and the High Voltage Research Laboratory

of the Massachusetts Institute of

Technology. Effects of radiation,

electrode geometry, and polarity on corona inception in SF 6 have been

measured. Corona inception voltages and

discharge initiation volumes have been

calculated using the streamer criterion.

Limitations of the streamer criterion as applied to SF

& in highly nonuniform

fields are discussed.

The statistics of electron avalanche

growth in SF6 have been measured and

compared with results of theory. While

the avalanche pulses, on average, followed expected theoretical behavior,

the distribution was not found to be

regular or to follow a simple stochastic

theory. A thorough compilation and

survey of electron swarm data for electro-negative gases used, and proposed

for use, as components of gaseous dielectrics was completed. The parameters

considered include: electron drift

velocity, attachment coefficient,

ionization coefficient, electron growth

constant, diffusion coefficient, detachment coefficient, and characteristic

energy. These are quantities needed for

prediction of breakdown and modelling of

gas discharges. Some of the important

gases included in this study are: 0 2

, CO,, SF 6

, H

2 0), air, nitrogen oxides,

halogens, and various halogenated

hydrocarbons, e.g., CF4

, C^Fg, C

3 F8

, C

4

F io , CC1,F2

, CC1F

3

, c-C4 F^, c-CcF^,

Ch

3 Br, CH

2

C1 o, CHC1 3

, etc. In this

report we include only an example of the

data collected, namely that for SF 6. Using a gas-chromatograph/mass

spectrometer, absolute concentrations of

S0F2 and S02 F

2 and relative concentrations of H

2 0 in SF6 have been measured

as a function of total energy dissipated

in corona discharges operated at power

levels between 50 and 700 mW. The

observed production rates for S0F 2 and

S0 2 F

2 appear to be proportional to power

level, and the ratio of S0 2 F

2 to S0F 2 concentrations for corona is considerably higher than that typically observed

for arc discharges in SF6

. [(301) 921-3121]

Superconductors

Released for Publication
Page 18 CEEE Technical Progress Bulletin - July 83

Superconductors , cont'd.

Ekln, J.W., j-B-T-e Interaction In

A15, Bl, and C15 Crystal Structure

Superconductors, submitted to

Proc. Applied Superconductivity

Conference.

Experimental evidence is presented which

indicates that the elastic strain effect

on the critical current of high-field

compound superconductors correlates

strongly with the type of superconductor

crystal structure. Large strain effects

are observed in all practical A15 super

conductors examined to date, including

Nb3Sn, Nb-Hf/Cu-Sn-Ga, Nb3Al , and V3Ga.

Strain is observed to have no measurable

effect, however, on either the critical

current or the critical field of superconductors having the Bl crystal structure [V 2

( Hf , Zr ) ] . Strain limits placed

on the mechanical design of superconducting devices are evaluated as a function of magnetic field for several

A15 superconductors (Nb3Sn, Nb-Hf/Sn-Ga,

and V

3 Ga) and compared with the strain

limits imposed by Bl and C15 superconductors. It is shown that the latter

materials have mechanical design advantage in applications where the superconductor is subjected to strain (either

compressive or tensile) in excess of

0.2%. [(303) 497-5448]

Fickett, F.R., Oxygen-Free Copper at

4K, submitted to Proc. Applied

Superconductivity Conference.

Oxygen-free copper is the most common material used for stabilizing practical

superconductors. This type of copper

may show residual resistance ratios

( RRR) that vary from 50 to 700 in the

full soft condition. Knowledge of the

exact RRR value is often essential for

optimum system design. We have investigated the effect of stress, temper, and

reanneal on the RRR and magneto-resistance of several hundred samples of

oxygen-free copper from many sources.

In this paper we describe the program

and present a sampling of the results

obtained to date. [(303) 921-3785]

Fickett, F. R., Goldfarb, R. B., Magnetic Properties, submitted to book,

Materials at Low Temperatures,

Chapter 6.

The magnetic properties of materials at

low temperatures and techniques for

their measurement are described. The low

temperature literature is reviewed. The

emphasis of the review is on metals and

alloys of technological Importance.

Similarly, the treatment of theory and

of measurement techniques Is aimed

toward the user interested In the more

practical aspects of the subject. In every instance, however, references are given which allow the reader to pursue

the subject at any level he may desire.

[(303) 497-3785]

Gavaler, J.R., Greggl , 0., Wllmer, R.,

Ekln, J.W., Properties of NbN Films

Crystallized from the Amorphous

State, submitted to IEEE Trans.

Magnetics, MAG-19.

Cubic Bl structure NbN was prepared by

annealing amorphous Nb-N films made by

sputtering niobium in an argon-nitrogen

atmosphere onto low temperature ( 350°C)

substrates. Crystallized films on sapphire substrates have equiaxed grains

while films on niobium are columnar.

Grain sizes vary from 125 A to >1000 A.

The highest superconducting critical

properties measured in these films are:

Tc

= 16K, J c (4.2, zero field) = 8 x 105 Amps/cm2

, and HC 2(1.3K) = 280

kG. Data on the effect of uniaxial

tensile strain on J c show that there

is no measurable elastic (reversible)

strain effect. Irreversible J c degradation begins at an intrinsic

tensile strain of 1.3% in the best case. [(303) 497-5448]

Goodrich, L.F., The Effect of Field

Orientation on Current Transfer In

Multlfl lament ary Superconductors

,

submitted to Proc. Applied

Superconductivity Conference.

Experimental data and discussion are presented on the current distribution
CEEE Technical Progress Bulletin - July 83 Page 19

Superconductors

,

cont'd.

when subject to multiple parallel and

perpendicular magnetic fields along the

length of a superconducting wire. The

experimental data were taken on a rectangular pancake coil with the

applied magnetic field in the plane of

the coil. These data indicate that

significant current transfer occurs in

the first and last perpendi cul ar magnetic field sections and little

transfer occurs between these two

sections. The implication for

superconducting magnet design will also

be discussed. [(303) 497-3143]

Hong, M. , Hull, G.W., Holthuis, O.T.,

Hassenzahl , W.V., and Ekin, J.W.,

Multifilamentary Nb-NB3 Sn Composite by

Liquid Infiltration Method: Superconducting, Metallurgical, and Mechanical Properties, submitted to

Proc. Applied Superconductivity

Conference.

A rapid solid-liquid reaction mechanism

has been used to form A15 Nb 3 Sn in the

liquid-infiltration processed Nb-Sn

wire. Small, equiaxed A15 grains across

the fine reacted filaments of 0. 2-1.0 u thickness were revealed with the transmission electron microscopy studies. A

uniform Sn concentration near the

stoichiometry was found in the A15

region. High inductive Tc 's of 17.9 K with sharp transition widths (<0.3 Kl and excellent overall J c

' s of 10^

A/cm2 at 19 T and 4.2 K were achieved.

Mechanical properties of the reacted

wire are not worse than those of typical

commercial bronze-process Nb3Sn con- ductors, and e(irrev) is slightly

higher.

[Contact: Ekin (303) 497-5448]

Recently Published

Ekin, J.W., Effect of Strain on the

Critical Current and Critical Field of

B1 Structure NbN Superconductors,

Applied Physics Letters 41(10)

p. 996, November 1982.

The effect of uniaxial strain on the

critical current of NbN superconductors

has been measured at 4.2 K in magnetic

fields from 6 to 22 T. Unlike A15

superconductors, the critical current of

B1 structure NbN shows no measurable

dependence on elastic strain, even at

fields as high as 22 T. Furthermore,

the bulk upper critical field determined

from the high field critical current

data is independent of uniaxial strain

within experimental error (.5%). The

irreversible strain limit e(irrev) where

the superconductor is permanently

damaged was measured to be greater than

0.7% (0.5% intrinsic strain) in 0.2-)m

thick-film samples. Values of e(irrev) were observed to correlate with the

microstructure of the NbN films as well

as with the onset of substrate yielding.

[(303) 497-5448]

Goldfarb, R.B., Fickett, F.R., Rao,

K. V. , Chen, H.S., Spin-freezing Below

the Ferromagnetic Transition Determined

by the Imaginary Component of ac Magnetic Susceptibility, J. Applied

Physics, 53(11), p. 7687 (November

1982).

The temperature dependences of the real

and imaginary components of ac magnetic

susceptibility have been measured for a number of amorphous Fe-Mn and Fe-Ni alloys. The alloys have paramagnetic,

ferromagnetic, and spin-glass intervals

as a function of decreasing temperature.

The spin-freezing temperature, Tfg is

identified by examining the imaginary

susceptibility x"* With decreasing temperature, x" » representative of losses,

begins to increase at the Curie temperature Tc, and reaches a peak at a temperature identified as Tfg. No peak is seen at Tc. The real susceptibility x' increases rapidly at Tc but decreases

before reaching Tfg. For frequencies of

10 and 20 Hz, the peak magnitude of x"

is about half that of x'* The results

suggest that Tfg may be unambiguously

defined by a peak in x" in the case of

spin glasses with intervening ferromagnetic states. [(303) 497-3650]
Page 20

ELECTROMAGNETIC INTERFERENCE

Released for Publication

Crawford, M.L., Improving the Repeat

ability of EM Susceptibility Measure

ments of Electronic Components When

Using TEM Cells, submitted to SAE

Technical Paper Series 830607, International Congress and Exposition,

Detroit, MI, February 28 - March 4,

1983

This paper outlines a systematic approach, using a TEM cell, for evaluating

the electromagnetic (EM) radiated sus- ceptibility of electronic equipment.

The purpose of the paper is to provide

guidelines, for those using TEM cells

for performing EM susceptibility meas- urements, to improve the repeatability

and, hence, the value of their test

results. The paper describes the test

setup, details the step-by-step procedures to use in performing susceptibility measurements, and discusses pertinent information related to the range of

application and limitations associated

with the use of TEM cells.

[(303) 497-5497]

Kanda, M., Ries, F.X., Driver, L.D. , and

Orr, R.D., Electric and Magnetic

Field Sensor Concept for Simultaneous

Near-Field Electromagnetic Field Measurements, submitted to Proc. 1983

EMC Symposium and Exhibition, Zurich,

Switzerland, March 8-10, 1983.

This paper describes a single sensor to

perform simultaneous near-field electric

and magnetic field measurements. The

theory indicates that it is possible to

obtain the loop-mode and dipole-mode

currents using a loop terminated with

identical loads at diametrically opposite points. The theory also indicates

that it is possible to adjust the loopmode and dipole-mode by adjusting the

load impedance, and thus obtaining an ideal load impedance for achieving equal

electric and magnetic responses of the

loop. Preliminary experiments have been

performed to verify these results.

CEEE Technical Progress Bulletin - July 83

[(303) 497-5320]

Koepke, G.H., and Ma , M.T., A New

Method for Determining the Emission

Characteristics of an Unknown Interfer- ence Source, submitted to Proc. 1983

EMC Symposium and Exhibition, Zurich,

Switzerland, March 8-10, 1983.

Quantitative determination of the radiation characteristics of an unknown interference source is of importance to

the users, manufacturers, and regulatory

authorities. The theoretical background

and measurement procedures for a new method to achieve this objective are presented with experimental results.

[Contact: Ma, (303) 497-3800]

Recently Published

Chew, H., Electromagnetic Modeling of

011 Shale Retorts for Remote Sensing

Purposes, IEEE Trans. Geoscience and

Remote Sensing, GE-20, No. 4, pp. 510-

517 (October 1982).

We report here some work on the modeling

of oil shale retorts for electromagnetic

sensing techniques. The aim is to obtain useful information about the con- tents of the retort (e.g., rubble size,

void ratio, etc.) by means of electromagnetic probes. In this work, the

retort is modeled by a spheriod with an average dielectric constant which depends on the void ratio. The near field

due to a radiating dipole source in the

vicinity of a spheroidal retort is com- puted using the Extended Boundary Condition Method due to Waterman, Barber, and

Yeh. Numerical results are given at 4

MHz for a retort with major axis 45.7

(150 ft.), minor axis 25.1 m (82.5 ft.),

bulk dielectric constant 8.8 + 3. 7 j , and

various void ratios. The results indicate feasibility of determining the void

ratio by remote electromagnetic measurements. It is also believed that this

work may be of interest beyond the

immediate context of oil shale retort

modeling. Contact: R. Jesch,

[(303) 497-3496]
CEEE Technical Progress Bulletin - July 83 Page 21

Electromagnetic Interference , cont'd.

Ma, M.T., and Koepke, G.H., A Method

to Quantify Radiation Characteristics

of an Unknown Interference Source,

NBS Tech. Note 1059 (October 1982).

A new method for determining the radiation characteristics of leakage from

electronic equipment for interference

studies is described in this report.

Basically, an unintentional leakage source is considered to be electrically

small, and may be characterized by three

equivalent orthogonal electric and magnetic dipole moments. When an unknown source object is placed at the center of

a transverse electromagnetic ( TEM) cell,

its radiated energy couples into the

fundamental transmission mode and propagates toward the two output ports of the

TEM cell. With a hybrid junction inserted into a loop connecting the cell

output ports, one is able to measure the

sum and difference powers and the relative phase between the sum and difference outputs. Systematic measurements

of these powers and phases at six different source object positions, based on

a well -developed theory, are sufficient

to determine the amplitudes and phases

of the unknown component dipole moments,

from which the detailed free-space radiation pattern of the unknown source and

the total radiated power can be determined. Results of simulated theoretical

examples and an experiment using a spherical dipole radiator are given to

illustrate the theory and measurement

procedure. [(303) 497-3800]

Taggart, H.E., Radiated EMI Instrumentation Errors, EMC Technology,

Magazine, Vol . 1, No. 4, pp. 26-35.

The purpose of this article is to address the various types of instrumentation errors that can be encountered when

performing EMI measurements. The various types of errors associated with the

instrumentation will be discussed and

suggestions made as to how they can be

reduced. Since the instrumentation

consists of basically an antenna connected to a receiver, the errors associated

with the antenna, the receiver, and

connecting cables will be addressed.

Calibration errors associated with the

various parts of an EMI measuring system

are discussed. These include (1) antenna calibration errors (loops, monopoles,

and dipoles), (2) receiver calibration

errors (rf voltmeter, attenuator, and

linearity), (3) mismatch errors (antenna

and receiver) and (4) antenna ground

effect errors. A table summarizing

these errors is included in the conclusions. [303) 497-3462]

CEEE CALENDAR

1983

September 12-13 (Gaithersburg, MD)

The IEEE CHMT Society and NBS are jointly sponsoring the VLSI Chip Packaging

Workshop. New developments and

critical overviews in the following

areas will be presented: hermetic,

plastic package design and evaluation;

package thermal design, characteristics,

problems, and test methods; bonding and

interconnections for high lead count

devices; coordinated chip, interconnection and package design, including

design for automatic assembly; materials

for VLSI packaging; die attach methods

and problems for large chips; and new package-related failure mechanisms.

[Contact: G.G. Harman (301 ) 921-3621]

November 14-16 (Boulder, CO)

15th Annual Symposium on Optical

Materials for High Power Lasers (Laser

Damage Symposium). This Symposium,

now in its 15th year, has become the

major forum for information exchange on problems of high power laser materials.

The Symposium is an outgrowth of the

activities of the ASTM Subcommittee on Laser Standards. The subject matter of

this year's symposium is about equally
Page 22

CEEE CALENDAR, cont'd.

CEEE Technical Progress Bulletin - July 83

divided between problems of high power

laser materials, especially thin film

coatings, of importance in laser fusion,

and problems of CW lasers, especially in

the infrared, relevant to DoD applications. There will also be discussion of

the problems of uv and visible lasers,

of long term interest in both agencies.

NBS has co-sponsored this meeting since

its inception.

[Contacts: Susie Rivera (303) 497-5342

or Kit Kline (303) 497-3678]

December 8 (Gaithersburg, MD)

The IEEE Electron Devices Society and

NBS are co-sponsoring the Power

Semiconductor Devices Workshop, which

is designed to bring together those

actively working in the field of power

semiconductor devices. The Workshop

will be held in conjunction with the

IEEE International Electron Devices

Meeting in Washington, D.C.

[Contact: F. Oettinger, (301) 921-3541]

1984

February 6-10 (San Jose, CA)

The Symposium on Semiconductor

Processing will be sponsored by ASTM

and co-sponsored by NBS, SEMI, and

Stanford University. Technical sessions

will address new problems arising from

rapid increases in device complexity and

performance and the emergence of

integrated systems-on-a-chip, automated

factories, and silicon foundries.

[Contact: R.I. Scace, (301) 921-3786]

June 18-21 (Gaithersburg, MD)

applications, and the latest advances In

power electronics.

[Contact: F. Oettinger (301 ) 921-3541]

SPONSORS OF WORK REPORTED IN THIS ISSUE

National Bureau of Standards

Department of Defense

Defense Advanced Research Project

Agency; Calibration Coordination

Group; Defense Nuclear Agency

U. S. Ai r Force

Bolling Air Force Base; Kirtland

AFB; Newark Air Force Station; Space

Division; Wright-Patterson AFB

U.S. Army

Aviation Research & Development

Command; Fort Huachuca; Fort Monmouth; Materials & Mechanics

Research Center; Redstone Arsenal

U.S. Navy

Aviation Logistics Center (Patuxent

River); Medical Research & Development Command; Metrology Engineering

Center (Seal Beach); Naval Air Systems Command; Naval Ship Research

Development Center; Naval Sea Systems Command; Naval Surface Weapons

Center; Naval Surface Weapons Center

(Crane); Office of Naval Research

Department of Energy

Bonneville Power Administration;

Energy Systems Research; Fusion

Energy

Department of Justice

Law Enforcement Assistance

Admi ni strati on Department of Transportation

National Highway Traffic Safety

Admi ni strati on Environmental Protection Agency

International Copper Research

Association

Sandia Laboratories

Co-sponsored by IEEE and NBS, the

Power Electronics Specialist Conference,

will bring together specialists in circuits, systems, electron devices, magnetics, control theory, Instrumentation,

and power engineering for discussions of

new ideas, research, development,
MBS.114A (wev. a-«0)

I. Publication D*t*

July 1983

U.«. DIPT, OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instruction s)

1. PUBLICATION OR

REPORT NO.

NBSIR 83-2719

2. Performing Organ. Roport No

Center for Electronic!

& Electrical Engineer ng

4. TITLE AND SUBTITLE

Center for Electronics and Electrical Engineering Technical Progress Bulletin,

Covering Center Programs, October 1982 - December 1982

5. AW=FH©ftfS)-

Compiler J. Franklin Mayo-Wells

6. PERFORMING ORGANIZATION (If joint or other than NBS, see Instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

I. Type of Report & Period Covered

October 1982

December 1982

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State. ZIP)

U. S. Department of Commerce

National Bureau of Standards

National Engineering Laboratory

Center for Electronics and Electrical Engineering

10. SUPPLEMENTARY NOTES

All technical information included in this document has been approved for

publication previously.

[7 ] Document describes a computer program; SF-185. FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document Includes a significant

bibliography or literature survey, mention it here

This is the third issue of an abstract bulletin to be Issued quarterly by the

Center for Electronics and Electrical Engineering, National Bureau of Standards.

This issue covers the work of the Center's programs for the first quarter of

Federal fiscal year 1983. Abstracts are provided by technical area for both

published papers and papers approved by NBS for publication.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicoion s) antennas; electrical engineering; electrical power; electromagnetic interference;

electronics; instrumentation; lasers; magnetics; microwave; optical fibers;

semiconductors; superconductors.

13. AVAILABILITY

| Unlimited

[777] For Official Distribution. Do Not Release to NTIS

[ 7] Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402. OOruer From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

25

15. Price

$7.00

U S COMM- D C 6043-P80


CENTER FOR

ELECTRONICS AND ELECTRICAL ENGINEERING

I

Applied Electrical Measurements

Electronic Instrumentation and Metrology

H

Antenna Systems

I IMetrology _

_|

Fields H

Characterization

Interference

Characterization

HMicrowave Metrology

Optical Electronic Metrology

Cryoelectronics

Metrology

Superconductors

and Magnetic

Materials

H

I Metrology

I Defect Metrology

H

Dimensional

I IMetrology

H

SEMICONDUCTOR

DEVICES AND

ciRCuns

DIVISION

Integrated

Circuit Test

Structures

Device and

Process

Modeling

Device Metrology

KEY CONTACTS:

Center (720)

Director Mr. Judson C. French

Acting Deputy Director Dr. Donald B. Sullivan

Administrative Officer Ms. Carol P. Mull is

Electrosystems Division (722)

Chief Dr. Oskars Petersons

Electromagnetic Fields Division (723)

Chief Mr. Charles K. S. Miller

Electromagnetic Technology Division (724)

Chief Dr. Robert A. Kamper

Semiconductor Materials and Processes Division (725)

Chief Mr. Robert I. Scace

Semiconductor Devices and Circuits Division (726)

Chief Dr. Kenneth F. Galloway

(301)921-3357

(301 ) 921 -3357

(301)921-3821

(301 ) 921 -2328

(303)497-31 31

(303)497-3535

(301 ) 9 21 -3786

(301)921-3541

INFORMATION:

For additional information on the Center for Electronics and Electrical

Engineering, write to or call:

Center for Electronics and Electrical Engineering

National Bureau of Standards

Metrology Building, Room B-358

Washington, DC 20234 Telephone (301 )921^-3357

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