Copy of Copy of Comp020604.qxd


The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

1.  Introduction

The advanced society is strongly supported by electron-
ics. With the progress of society, much more aid of elec-
tronics in the wide area including hard environment
("Hard Electronics"), such as high-temperature, high
power, high irradiation, and high frequency, is needed.
The term of "Hard Electronics" was incepted in Japan in
1991. It means a new kind of electronics needed in hard
circumstances utilizing hard materials, which are essen-
tially tough themselves and very hard to be handled.  The 
hard materials involve wide band gap semiconductors and 
new  kind  of  oxides (Ma et al. 2002; Prelas et al. 2002;
_______________________________________
*Corresponding author's e-mail: touatif@squ.edu.om

Spitsyn et al. 2002).  Hard electronics research continued 
to develop  throughout  the 80s with increasing emphasis 
on  high-temperature   operation,  i.e.   high-temperature 
electronics (HTEs) (Patrick et al. 1997). The energy crisis
precipitated by the Middle East saw a clear focus on
improving petroleum recovery from oil wells by improved
down hole monitoring, necessitating increased tempera-
ture coverage by the  electronic  systems. There   are
many   equally potential applications with increasing com-
mercial opportunities afforded by programs of More
Electric Aircraft and More Electric Vehicles (Kodjak,
1993 and 1996).  

A main theme also has been in distributed control sys-
tems for improved reliability and increased fuel economy,
either directly by improved combustion control or indi-

High-Temperature Electronics: Status and Future Prospects
in the 21st Century
F. Touati*, F. Mnif and A. Lawati

Department of Electrical and Computer Engineering, Sultan Qaboos University, P. O. Box 33, Al-Khoud, Muscat, 123, 
Sultanate of Oman

Received 2 June 2004; accepted 18 September 2005

Abstract: This paper reviews the state of current electronics and states the drive toward high-temperature electronics. The
problems specific to high-temperature effects on conventional electronics and prospects of alternative technologies like
silicon-on-insulator, silicon carbide, and diamond are discussed. Improving petroleum recovery from oil wells with high-
temperature coverage of downhole electronics, making combustion processes more efficient utilizing embedded electron-
ics, programs for More Electric Aircraft and Vehicles necessitating distributed control systems, and environmental pro-
tection issues stress the need to use and develop high-temperature electronics. This makes high-temperature electronics a
key-enabling technology in the 21st century. Actual applications using high-temperature electronics are discussed in some
details. Also information and guidelines are included about supporting electronics needed to make a complete high-tem-
perature system. The technology has been making major advancements and is expected to account for 20% of the elec-
tronics market by 2010.  However, many technical challenges have to be solved.  

Keywords: High temperature, Hard  electronics, Downhole  monitoring, Electric  aircrafts  and
vehicles, Efficient use of energy, Distributed control systems

.øjô°û©©dGh  …OÉ◊G  ¿ô≤dG  ‘  á«∏Ñ≤à°ùŸŸG  äÉ©bƒàdGh  ‹É◊G  ™°VƒdG  :á«dÉ©dG  IQGô◊G  äÉ«fhεdG

»àjƒJ .±@≈«JGƒdG .´  h ∞«æe .± ,

::áá°°UUÓÓNNäÉ«fhεdÓd á≤aGôŸG πcÉ°ûŸG åëÑdG Gòg ¢ûbÉæj .á«dÉ©dG IQGô◊G äÉ«fhεdG ¤G ∫É≤àf’G Ò°S í°Vƒjh É«dÉM á∏ª©à°ùŸG äÉ«fhεdÓd á©LGôe åëÑdG Gòg øª° àj

á°SÉŸG IQhô° dG äÉ≤«Ñ£àdG øe ~j~©dG í°VƒJ .¢SÉŸGh ¿ƒµ«∏°ùdG ~«HQÉc ,∫RÉ©dG - ≈∏Y - ¿ƒµ«∏°ùdG äÉ«æ≤J øe É¡d á©bƒàŸG πFG~ÑdGh IQGô◊G äÉLQO ´ÉØJQG AÉæKG áj~«∏≤àdG

i~e IOÉjR ∫ÓN øe ôØ◊G πNGO áÑbGôŸG Iõ¡LG ôjƒ£àH §ØædG QÉHBG øe ∫hÎÑdG ¢UÓîà°SG ôjƒ£J :äÉ≤«Ñ£àdG √òg ºgCG øeh .á«dÉ©dG IQGô◊G äÉ«fhεdG ôjƒ£Jh ΩG~îà°S’

ÌcG ~ªà©J π≤f §FÉ°Sh hG äGôFÉW êÉàf’ IQƒ£àŸG èeGÈdG ,Iô°ûàæŸG äÉ«fhεdG  Iõ¡LG ΩG~îà°SÉH IAÉØc ÌcG ¥GÎM’G äGƒ£N π©L ,É¡JÉ«fhεdG πÑb øe √É£¨ŸG IQGô◊G

¿ô≤dG É«Lƒ∏æµJ ‘ ~YÉ°ùe ÉMÉàØe á«dÉ©dG IQGô◊G äÉ«fhεdG π©éj Gòg πc .áÄ«ÑdG ájɪëH á≤∏©àŸG äÉ≤«Ñ£àdG GÒNGh ,Iô°ûàæe Iô£«°S Iõ¡LG ¤G áLÉëH ¿ƒµJ AÉHô¡µdG ≈∏Y

πLG øe äÉ«fhεd’G ºY~d äGOÉ°TQ’Gh äÉeƒ∏©ŸG É° jG åëÑdG øª° àj ɪc .åëÑdG ‘ É¡à°ûbÉæe ” á«dÉ©dG IQGô◊G äÉ«fhεd’ á«∏©ØdG äÉ≤«Ñ£àdG øe ~j~©dG .øjô°û©dGh …OÉ◊G

~j~©dG ¿Éa Gòg ™e .2010 ΩÉY ™e äÉ«fhεd’G ¥ƒ°S øe %20 »£¨J ¿CG ™bƒàŸGh É«Lƒ∏æµàdG √òg ≈∏Y CGôW ÒÑc Ω~≤J ∑Éæg .á«dÉ©dG IQGô◊G äÉ«fhεd’ πeÉc Ωɶf AÉæH

.πM ¤G áLÉëH á«æ≤àdG äÉj~ëàdG øe

::áá««MMÉÉààØØŸŸGG  ääGGOOôôØØŸŸGGIõ¡MG ,É«Lƒdƒæµà∏d CÉØc’G ΩG~îà°S’G ,AÉHô¡µdG ≈∏Y ÌcG ~ªà©J π≤f §FÉ°Shh äGôFÉW ,ôØ◊G πNGO áÑbGôŸG ,áÑ∏°üdG äÉ«fhεd’G ,á«dÉ©dG IQÉ◊G äÉ«fhεdG

.Iô°ûàæŸG Iô£«°ùdG



44

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

rectly by reduced weight by reducing the requirement for
ancillary equipment. There are still many problems to
overcome for the full adoption of HTE systems in "every-
day" electronics. High-temperature designs need compo-
nents rated to operate in the hard environment in which
they will be used.

This paper reviews the state and future prospects of
HTEs as a technology increasingly affecting strategic sec-
tors in the 21st century. Some details of actual applica-
tions using HTEs have been discussed. Information has
also been included about components and materials need-
ed to make a complete high-temperature system.  

2. High-Temperature Effects on Device
Properties

2.1  General Tendency
As temperature increases in a semiconductor, there are

challenging issues to resolve (Lall et al. 1997):

-  Intrinsic carrier density increases.
-  Junction leakage current increases exponentially (p-n

junctions, BJTs, and FETs), which presents the
biggest problem.

-  Device parameters vary (forward bias voltage, thresh-
old voltage, forward current, carrier mobility, input
impedance, transconductance, susceptibility to
latchup).

-  Electromigration of interconnection traces increases.
-  Chemical reactivity of ohmic contacts increases.
-  Dielectric breakdown strengths decrease.
-  TEC mismatches stress the die mechanically.

The most important physical properties for a good high-

temperature semiconductor material are a wide bandgap
and high thermal conductivity.

-  Bandgap, because it determines the amount of leakage
current across the junction.

-  Thermal conductivity, because it determines the semi-
conductor's ability to dissipate heat to the ambient
environment. 

The above effects show that the temperature is a major
limitation for electronic devices. The upper temperature
limit for conventional electronics is 100oC, with some
special military components being operated at a maximum
of 125oC as shown in Fig. 1.  Possible way to cope with a
high-temperature environment is to use active cooling
systems and to place electronics some distance away in a
moderate environment. However, large, heavy, and com-
plex cooling systems and the cabling and interconnections
they require are not at all advantageous from the view-
point of accuracy, reliability, size and cost. The develop-
ment of HTEs is, therefore, eagerly sought after. 

2.2  Bipolar Technology
Typically, amplifiers must have low offset, high imped-

ance, and high gain to minimize errors in a control loop.
Unfortunately, bipolar junction transistors, which are typ-
ically used for these reasons, do not work well at high
temperatures because of:

- Forward current gain increases with temperature at 
about 30%/100ºC.

- Forward voltage decreases at about 200 mV/100ºC.
- Reverse leakage of the base/collector junction with

open emitter doubles every 8ºC.

Figure 1.  Temperature limits for electronic applications

*EOR = Enhanced Oil Recovery

oC



45

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

- Resistivity of silicon (Si), which is temperature
dependent.

-  A loss of linearity that occurs in the saturation region
with temperature increase.

Increasing leakage current, which is often the dominant
effect, eventually causes loss of rectification and isolation.
Bipolar circuits start to fail above 150ºC. In the bipolar
transistor characteristics, not only is the collector current
dramatically reduced, but there is significant distortion
and loss of linearity at high temperatures. Also, the output
resistance is not constant.

2.3  CMOS Technology
At high temperatures, CMOS devices also experience

reduced performance. Unfortunately, most devices are not
tested above 150ºC.

Characterization testing of a typical MOSFET device
in the range of 100ºC-200ºC indicates that:

- Breakdown voltage increases with temperature at
about 8%/100ºC.

- On-resistance increases with temperature at about
70%/100ºC.

-  Leakage current increases rapidly with temperature,
changing four orders of magnitude/100ºC, doubling
every 8 ºC.

-  Gate-source threshold voltage decreases with temper-
ature, about 24%/100ºC.

-  Conventional CMOS and MOSFET devices usually
operate to 160ºC. With dielectric isolation, this limit
can be extended to about 200ºC, and when designed
for high temperature, to about 300ºC. 

3.  Why Are High-Temperature Electronics
Needed?

The industries most interested in designing products
using HTEs today can be broken along field lines as fol-
lows:

3.1 Oil and Gas Well Logging 
The energy crises of the 70s backed by a second ener-

gy crisis precipitated by the Middle East nations emphasis
on the need for a clear focus on improving petroleum
recovery from oil wells by improved downhole monitor-
ing, necessitated increased temperature coverage by
downhole instruments. This requires sensors and data
acquisition systems used to log the environment around
drilling heads in wells, measuring reservoir potential and
environmental conditions, and geothermal implementa-
tion of 'permanent sensors' intended to allow long life; up
to 5 years operation with no failures. This will also help
discovering new markets in deeper (i.e. hotter) wells oper-
ating at 400oC and above. 

This has presented electronics with a challenging envi-
ronment. Locating an instrument for pressure or flow
measurement at the end of  3 miles of wire poses problems

for electronics including temperatures of 185°C (extended
periods) to 250°C (shorter periods).  Geothermal wells
push continuous operating temperatures to 300°C, with
survival to 350°C required (Normann, 1998). Traditional
limits of several hours to 100 hours are being pushed out
to several thousand hours, and in the case of permanent
gages, to several years of continuous operation. There are
three typical types of instruments which are discussed
below.

3.1.1  Logging Tools 
Logging tools are deployed for gathering snapshot

information revealing the quality and potential production
of the well. These can be wire-connected (wireline tools,
receiving power and communications from the surface) or
steel cable connected (memory tools, which are self-pow-
ered and contain memory which is retrieved with the tool).

3.1.2  Measurement while Drilling Tools
These are used for directional drilling information such

as hole inclination, hole azimuth, and the tool face direc-
tion. In addition, other measurements are now performed
including resistivity, natural gamma, and neutral density.
Downhole weight on bit, torque, vibration levels and
accelerations are sometimes also incorporated into the
measurement. This environment is extremely rugged
requiring endurance of high vibrations and shock and
thermal cycling every several days as the bit is pulled up
and changed. Because of the high cost of drilling opera-
tions ($20,000 to $100,000 per day) these instruments
need to be highly reliable. In some cases, the drilling oper-
ation is allowed to continue without operating instrumen-
tation.

3.1.3  Permanent Gauges
Permanent gauges are installed in producing wells and

monitored at the surface periodically over several years.
Temperature, pressure, flow and different chemical sen-
sors are deployed. These devices must have good long-
term stability without susceptibility to premature wearout
mechanisms such as electromigration (discussed later).  

3.2   Military and Space
The mechanisms of failure of electronic components

are being looked at afresh. Until quite recently the US
Military Handbook 217 provided design guidelines link-
ing failure rate exponentially to steady state temperature
which led to overly large cooling systems adding weight,
cost and complexity to aircraft. From the engine manufac-
turers' viewpoint, transducers with high-temperature capa-
bility would enable more accurate assessment of parame-
ters in hard environments. This would facilitate the
extended use of data buses to replace dedicated wiring
from engine probes to remote electronic processing cir-
cuits. The impact would give considerable weight and
reliability.  Total weight of connectors and wiring in the
harness is around 60-65 kg in current large civil aircraft. 

In the aerospace industry, HTEs could potentially



46

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

enable improved system designs resulting in lighter,
faster, cheaper, and more fuel-efficient aircraft. Most
severe environment is around the engine. Controlling
electronics operate in an ambient of up to 250oC and
cooled by routing and interfacing engine fuel (at less than
105oC) with the heat sinks. In two specialist applications,
electronics already operate above 100oC:

-  In electronic braking systems for large aircraft,
- UV flame detection for turbine engine combustor con

trol.

HTEs are also required for the implementation of mul-
tiplexed systems for gas turbine engine control, which
would enable complex cooling and connection require-
ments to be eliminated. Studies done at the US Air Force
Research Laboratory show that better regulation of engine
thrust can result in doubling of the thrust/weight ratio,
40% fuel burn reduction, at the same time providing a
35% decrease in engine life cycle costs (Lewis, 1998). To
achieve these goals, control logic must be designed to use
a broad array of hundreds of sensors/actuators operating
over a wide operating temperature range to control thrust
while protecting against aerodynamic, thermal, or materi-
al strength limitations. The engine case is a significant
source of radiant heat, approaching 560°C at high alti-
tudes.  Conventional uncooled electronics cannot be used
here because of thermally induced wear factors leading to
degradation and premature failure.  Although fuel cooling
has been very effective at improving the electronics envi-
ronment, this approach favors centralized control architec-
tures as well as the added weight and space required for
the cooling pumps, heat exchanger, and piping.

Also, deep space exploration of planets like Neptune
requires  electronics  which  are  able to  operate   below
-220°C on the surface of Triton or Pluto. Electronics for
Venus 2006-2007 missions need to operate at above
470°C and it seems that suitable HTEs may not be ready
in time except for "grab-and-go" or limited life" opera-
tions.  

3.3  Automotive
There is a rising need for More Electric Aircraft and

More Electric Vehicles which are more reliable, faster,
simpler, lighter, and less polluting. The automotive sector
presents, by far, the largest potential market for HTEs.
However, automotive applications will prove to be the
most difficult for HTE to penetrate, due to:

-  Extremely pricing pressures,
-  Very demanding requirements for long term reliability, 
-  The long cycles for new designs.

Five automotive applications will provide the main driv-
ers for HTEs and high-temperature power devices:

-  Engine control,
-  Transmission control,

-  ABS (antilock braking systems),
-  Active suspensions,
-  Sensors for wheel speed and MAP (Manifold Absolute 

Pressure (systems).

HTEs and sensors are becoming increasingly necessary
for automotive control applications such as Engine
Control Units (ECUs), in-cylinder pressure sensing and
camshaft position sensing because of international
requirements to rapidly reduce engine emissions.
Reducing emissions depends on more precise and local
control of valve timing, which in turn depends on primary,
not inferential, sensing of cylinder pressure and camshaft
position. Improveing the precision of these measurements
requires the sensors and signal conditioning electronics to
be mounted close to, or in some cases inside, the engine
itself.  ECUs,  typically mounted on the firewall of the
engine compartment, can also contribute to reduce emis-
sions by being mounted on the engine itself. The shorter
control loops to/from the ECU lead to more precise con-
trol. 

3.4 Efficient Energy Use and Environment
Protection

The global energy demand is growing at a rate of 3 to
4% a year. Accordingly, the world energy consumption
will double around 2050.  A survey of future carbon diox-
ide emission predicts environmental crisis such as:

-  Increase in atmospheric temperature,
-  Rise of sea surface level,
-  So this will be a challenge for mankind to avoid the cri-

sis in the 21st century. Three basic technological meas-
ures to take are as follows,
. Energy system change from fossil fuel to non-fossil 

fuel use,
. High efficiency energy utilization,
. Control of carbon dioxide emission and collection.

As to the energy system change, some report says that
today's ratio of fossil (80% of the 11 terawatts) to non-fos-
sil energy (20%) utilization have to be changed into the
ratio of 40% to 60% of the 30 terawatt total until middle
of the 21st century to stabilize carbon dioxide concentra-
tion in the air (Matin, 1998). Most of non-fossil energy
will be electricity, supplied by atomic energy and repro-
ducible natural energy such as solar energy, water power,
wind power and terrestrial heat. In Japan, about 40% of
the total input energy has been already supplied by elec-
tricity. The term high-efficiency energy utilization is two
fold. First, it will be more and more important for
mankind to develop high-efficiency electrical energy uti-
lization social system in this century, because electrical
energy demand will rapidly grow in the world. Second,
improvement of combustion control system is necessary
to attain efficient energy use and minimal pollution. As to



47

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

the first, expected electric power leading energy technolo-
gies for this century are:
-  Power generation: atomic, new systems to find out
-  Power transmission: power system linkage 
-  Power storage: pumped storage, hydraulic generation
- Power conversion: EV, high speed railway system

(inverters)
where power electronics will be essential for the new tech-
nologies. The corresponding power devices must, there-
fore, be of:

-  Low power consumption,
-  Higher switching speed,
-  Higher temperature operation.

As to the second, in Japan, in 1994 the Ministry of
International Trade and Industry (MITI) began the project
called "Research and Development on Combustion
Control for Energy conservation".  The project had a term
of 6 years. MITI has delegated management of the
research and development to the Ion Engineering
Research Institute Corporation through the New Energy
and Industrial Technology Development Organization
(NEDO). The objectives of this R&D are to establish tech-
nologies for realizing SiC-based devices applicable to the
advanced combustion control system as shown in Fig. 2.
More specifically, to achieve the advanced new system,
R&D is focused on SiC devices operable in a high-tem-
perature and oxidizing environment. 

3.5  Communication Sector
The communication sector is also very much concerned

by hard electronics devices. The communication systems
in 1970's to 1980's were characterized by:

-  High-power   land/satellite   base  stations  and   home  
receivers for broadcasting,

-   Analog transceiver  for   wireless  telecommunications

and cable network communication.

From the beginning of 1990's, new systems character-
ized by:
-  Very small-sized personal mobile telephones (cellular),
-  Personal computer network (Internet).

have been implemented. Keywords in these new systems:
digital, high speed, mobile and personal. In the beginning
of this century, 50 cc size and 50 g weight cellular hand-
set (can be wristband type) with a high RF performance
has appeared. Also, for this century various high-frequen-
cy communications are projected. Very small base stations
are strongly demanded in order to install them on rooftops
of buildings. Hard electronics will contribute a great deal:

3.6  Other Applications
In addition, markets needing HTEs are forming in the

areas of integrated motor controls, industrial process con-
trols, building fire safety controls, environmental test
equipment, and other areas. A number of recent require-
ment changes have pushed the upper operating tempera-
ture range limit higher, as shown in Table 1.

Figure 2.  Schematic new combustion control system using SiC-based control devices

 Requirement   Effect on Product  
Explore new, 
deeper oil wells  

 Hotter, i.e., 
equipment exposed to 
higher temperatures  

Downhole  
drilling cost 
increased  

 Durable and more 
reliable equipment 
required  

Improve aircraft 
performa nce 

 Distributed engine 
controls  

Optimize fuel 
consumption  

 Lighter controls and 
monitors 

Remove cooling 
systems 

 Hotter operat ing 
conditions with no 
airflow or heat sink  



48

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

Standard, commercial off the shelf (COTS) bulk Si
processed semiconductors, however, are not able to han-
dle these increased demands. They are designed for a
service range of -55°C to +70°C for commercial, +85°C
for industrial or +125°C for military temperature range.
Use of these components beyond their intended range is
not specified or recommended by their manufacturers.

The discussion above on the various strategic sectors
emphasizes the need for devices having higher tempera-
ture ratings. In fact, the 2002 five-year update to the
International Technology Roadmap for Semiconductors
(ITRS) did not reflect the immediate need for higher oper-
ating temperatures for complex integrated circuits or
ASICs; but did recognize increasing temperature require-
ments for power and linear devices as shown in Table 1
(Johnson, 2004). 

Nevertheless, in the 2003 edition of the ITRS, the max-
imum junction temperatures identified for hard-environ-
ment complex integrated circuits was raised to 150°C
through 2018 (Johnson, 2004). The ambient operating
temperature extreme for hard-environment complex inte-
grated circuits was defined as 40°C to 125°C through
2009, increasing to 40°C to 150°C for 2010 and beyond.

4.  Status and Prospects of High-Temperature
Electronics 

4.1 High-Temperature Semiconductor Techno-
logies 

Generally, the main part of electronics is composed of
semiconductors. Ordinary semiconductors Si, germanium
(Ge), and gallium arsenide (GaAs), have rather small
energy gaps as shown in Table 2.

Due to the limitation of material properties caused by
the bandgap, they cannot withstand severe environment.
So, we need wide bandgap semiconductors such as silicon
carbide (SiC), gallium nitride, diamond, and oxides. The
same reason has been behind the interest shown on Si over
Ge (ESi, gap > EGe, gap) fifty years ago and the techno-
logical development of the Si industry so far. However, as
Table 3 shows, Si and silicon on insulator (SOI) are the
only technologies with good high-temperature character-
istics that is mature enough for production use.

SOI technology was originally developed to meet
Aerospace needs for instrumentation, data acquisition and
distributed control. The temperature and reliability
requirements for the Aerospace applications supported the

 2001 2002 2003 2004 2005 2006 2007 
Complex ICs  -40°C to 

+125°C 
-40°C to 
+125°C 

-40°C to 
+125°C 

-40°C to 
+125°C 

-40°C to 
+125°C 

-40°C to 
+125°C 

-40°C to 
+125°C 

Power/Linear  -40°C to 
+150°C 

-40°C to 
+150°C 

-40°C to 
+180°C 

-40°C to 
+180°C 

-40°C to 
+200°C 

-40°C to 
+200°C 

-40°C to 
+200°C 

 

Table 1.  International technology roadmap for semiconductors ambient operating temperatures
for hard environments (automotive)

Element Bandgap E g  
(eV) 

 

Electron 
mobility 
(cm/s) 

Breakdown 
voltage 
(V/cm) 

Si 1.12 1x107 2x104 

Ge 0.67 5x107 7x103 

GaAs 1.43 2x107 3x104 

SiC 2.2 - 3.00 2x107 25x105 

Diamond 4.8 1x107 8x10
5 

 

Table 2.  The main physical parameters for various
semiconductors

Technology Maturity Temperature Source Products 

Si CMOS (bulk)  Production  -50ºC to 150ºC  Multiple  Sensor I/F, Logic,  Memory, Power  
High-Temp. 
Tolerant Si (SOI)  Production  -50ºC to 300ºC  Honeywell  

Sensor I/F, Logic,  
Memory, Power  

E/D Gallium 
Arsenide (GaAs)  Production  -50ºC to 150ºC  Vitesse Logic, Memory  

Complimentary 
GaAs 

Development  -50ºC to 350ºC  Honeywell  Logic, Power  

SiC   Development  -50ºC to 60 0ºC CREE, 
Siemens, ABB  

Very Few (Discrete)  

Diamond Early 
development  

-50ºC to 1000ºC  Research labs  None 

Table 3.  High-temperature tolerant semiconductor technologies (HITEN, London, England)



49

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

development of reliable integrated circuits to operate for
long periods of time at high temperatures. With the fully-
depleted SOI MOS technology, Si has very good thermal
properties, theoretically reaching temperatures of 400°C,
and low power Si devices have been widely demonstrated
to operate at 300°C (Brusius, 1994; Lemnios, 1995; Naefe
et al. 1998; Pinardi, 2003; Shahidi et al. 1993). Since by
far, most applications operate under 300°C, Si-based tech-
nologies dominate the field now and will for many years
to come. Another major selling point for Si is that the
manufacturing technology is already in place for high vol-
ume and low cost products.

Alternatively, silicon carbides demonstrated ability to
function under extreme high-temperature, high-power,
and high-radiation conditions. Therefore, SiC is expected
to enable significant enhancements to a far-ranging vari-
ety of applications and systems. Specific applications
include high frequency, high power radar systems, jet
ignition systems, turbine engine monitoring and control,
spacecraft power conditioning, nuclear power instrumen-
tation, in-cylinder engine sensors, and numerous others.
However, improvements in crystal growth and device fab-
rication processes are needed before SiC-based devices
and circuits can be scaled-up and reliably incorporated
into electronic systems (Eriksson, 2002; Ziegler et al.
2004). 

In summary, temperature ranges for high-temperature
Electronics can be broken down into 3 ranges as shown in
Table 4. Market usage is also shown for relative impor-
tance.

4.2  HTEs Devices and Systems 
In the past few years research and development in digi-

tal, analog, and power devices for HTEs have been very
active. The ultimate goal is to integrate on-chip applica-
tion-specific integrated circuits (ASICs) as solutions for
cost, reliability, space/weight, and power issues. In the fol-
lowing sections, we are going to highlight recent applica-
tions.  

4.2.1  Digital Devices
Table 5 shows, mainly  well-documented high-digital

devices available in SOI and SiC technology. These
devices demonstrated good operations at temperatures up
to 300°C.  As can be seen, SOI technology is dominant.
Although it  is finding wide applications in power sys-
tems, it started also in the digital world and a lot of work
is being put to produce SiC-based high-temperature digi-
tal systems.

4.2.2  Analog Devices
High-temperature analog devices such as operational

amplifiers (HT1104), analog-to-digital (A/D) converters,
analog multiplexers and switches, 5V voltage references
all operating at 250°C and above, and many others are
commercially available (not restrictively from Honeywell,
IBM, and Cree).  A well-documented application of the
opamp HT1104 concerns the control of combustion
process in engines, as shown in Fig. 3, by either simple
flame indicators which have a binary output correspon-
ding to the occurrence of flame or not or more complex
light spectrum sensors which have a complete analog out-
put (Sims, 1996).

4.2.3  Power Devices
Far-ranging development and applications of power

devices have been reported. Recently, for example, in the
automotive sector, the impact of SiC power electronic
devices for hybrid electric vehicles, traction drives, DC-
DC converters, PWM inverters, and IGBTs with field stop

 

Temperature 
Range 

Percent 
of Market  

Recommend 
for lo-power 

Recommend  
for hi-power 

Up to 200ºC  90.2% SOI SOI 
200 to 300ºC  8.6% SOI SiC 
Above 300ºC  1.2% SiC SiC 

Table 4.  Recommended technologies for given tempe-
rature ranges (HITEN, London, England

Part Temp. 
Range 

Features Reference/Source  

SOI IBM microprocessor  To 300 ºC  >500MHz, 32b, 6.5M 
devices 

IBM Microelectronics 
Division. 

SOI microprocessor 
HT83C51 

To 300 ºC  20MHz, 8k ROM, 256 
bytes RAM, 3 -16b 
timer/counters  

Honeywell HT83C51  

SOI SRAM HT6256  To 300 ºC  200MHz, 32kx8 static 
RAM 

Honeywell HT6256  

SOI CMOS SRAM  To 250 ºC  64kb  (Fallet et al., 1996)   

SOI Gate Array HT 2007, 
2080, 2400  

To 300 ºC  Sea of 5 k to 200k 
transistor gates  

Honeywell HT 2007, 2080, 
2400 

SiC CMOS ICs  To 300 ºC  p-well process, 5V 
power supply  

(Ryu et al., 1997, 1998)  

Table 5.  Samples of available high-temperature digital devices



50

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

technology was studied (Tolbert et al. 2002 and 2003;
Ozpineci et al. 2002; Hasanuzzaman et al. 2004; Spitz et
al. 1998; Ishii et al. 2001; Matsumoto et al. 2001; Bauer
et al. 2001). Honeywell has reported the availability of
power positive and negative linear regulators (0.5A, ±5V,
±10V, ±15V) operating well above 200ºC. 

4.2.4  High-Temperature ASICs
VLSI technologies today offer the potential for inte-

grating mixed signal circuits as ASICs in high-tempera-
ture applications. This solution opens up the possibility of
obtaining microelectronics circuits at a lower cost and
with better reliability compared to discrete solutions.
Furthermore, the scale of the technology leads to reduced
power supply voltages, which in turn reduces the field lev-
els, the high-temperature effects and the power consump-

tion. As a result, low power supply voltage and high-tem-
perature operation can be used together effectively in the
design of high-temperature mixed signal ASICs
(Vermesan, 1997). Examples of such implementations are
described below.

SSI/LSI Components for hybrid-mounted: Typical sys-
tem control circuits involve analog and digital signal con-
ditioning and processing, memories and peripherals are
implemented (Fallet et al. 1996). Such components are
already available for hybrid mounting and operation
above 175°C. Examples of circuits designed for high-tem-
perature operation are shown in Fig. 4. 

Control electronics module for future All-Electric
Aircraft (AEA): An interesting example is the Actuator
Control Electronics (ACE) Module, shown in Fig. 5.  It is
targeted for completely distributed control in future AEA

Figure 3.  Block diagram of engine combustion control circuit

Figure 4.  Typical circuit architecture for system monitoring applications

Figure 5.  Targeted actuator control electronics module for future AEA applications

SE
N

SO
R

S

A
C

T
U

A
T

O
R

S



51
The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

and operation up to 200oC for the wings, 315oC for the
engines (Bottner et al. 1991). ACE modules will require
high-speed data bus interface, large memories, powerful
microprocessor, precision analog functions as well as
power drivers (Brown et al. 1994). The development of
such systems is still years ahead but a few circuits already
aim at this direction.

Downhole monitoring: The market for electronics in
instrumentation and control systems for downhole appli-
cations demands increased performance for gauges both
in terms of duration and temperature. Many companies
now require instrumentation equipment that can tolerate
up to 200°C up to two months. There is no doubt as to the
future market requirements - even higher temperatures for
longer periods. 

Figure 6 shows architecture for a wire line permanent
gage which utilizes a custom gate array and ASIC to inter-
face pulse width modulated pressure sensors and temper-
ature sensors, and a single bi-directional communication
line (Normann et al. 1998).

4.3 Support Electronics & Materials Used in
Making High-Temperature Circuits

4.3.1  Passive & Discrete Devices  
For passive components, packaging durability at high

temperatures is of prime importance. Very often, joining,
sealing, and package ruggedness are the main issues
affecting the reliability of the components, whereas the
basic property materials are very robust. There is a strong
desire to use Surface Mount Technology (SMT) compo-
nents. More passive high-temperature SMT components
are now available, making the decision to go to SMT eas-
ier (Naefe et al. 1998).

Resistors: Are the largest utilized components in elec-
tronic design. Therefore, failure modes, shifts, and ther-

mal drifts all can have very detrimental effects on circuits
designed for high-temperature operations. Honeywell,
Heraeus-Cermalloy, and Huntington Electric have for
example, manufactured wire wound, thick-film and thin-
film resistors for power applications. These resistors with-
stand temperatures above 200°C (Naefe et al. 1998;
Grzybowski et al. 1998).  To stay below their material
temperature limits, these resistors should be derated sig-
nificantly. 

Capacitors: The strong temperature dependency of the
dielectric constant makes capacitances change significant-
ly with increasing temperature. High-temperature capaci-
tors usually have low capacitance due to mechanical
breakage caused by thermal packaging stresses. That is
why capacitors will need to be paralleled to get high val-
ues. Electrolytic capacitors do not operate above 150°C
due to dielectric breakdown. Values of several tens of
microfarads are typically wet slug Tantalum devices.
Solid Tantalum capacitors are available in values of sever-
al microfarads. High-temperature ceramic capacitors tend
to be very stable for long periods of time exceeding 5000
hours in some tests, however, their values are usually
smaller than 0.1 microfarad. Teflon electrostatic capaci-
tors are being developed by Custom Electronics, which
have very low TC of capacitance from room to 200°C,
though the parts are usually small valued. Some published
temperature test results demonstrate that these capacitors
show gradual loss of functionality and initial aging shift in
capacitance e.g. Matsuo solid tantalum and NOVACAP
ceramic capacitors (Naefe et al. 1998; Grzybowski et al.
1998).

Electromigration: Probably the most significant limit-
ing aspect of an electronic component's lifetime at high
temperature is the ability of the metal films to carry cur-
rents for extended periods of time. Over years, or even
months, with sufficient current density present, metal

Figure 6.  Downhole tool architecture



52

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

atoms tend to migrate in an uncontrollable dissipation
manner (electromigration). Lifetimes can, thus, be
improved by reducing current density. Manufacturers of
high-temperature-tolerant electronics eliminate this issue
by using layout rules that allow at most 1/10 the current
density of conventional bulk Si design.

Ohmic contact and packaging: High temperatures cause
increased chemical reactivity of metal to Si junctions.
Metals with high electrical conductivity present poor
interfaces and thus do not form stable ohmic contacts. To
overcome this problem, intervening layers of materials
(e.g. TiW), called diffusion barriers, that are chemically
neutral to the interconnect metal and the semiconductor
contact, are being used. A significant amount of study is
devoted to researching ohmic contacts in SiC, an issue
that has slowed this technology from entering volume pro-
duction (Cole et al. 2002; Lee et al. 2003; Madsen, 2001;
Saxena et al. 1999; Touati and Saji, 1997).

It is also true that packaging and interconnection prob-
lems present some of the biggest challenges for electron-
ics at temperatures above 250ºC, often being more of a
barrier to successful operation than the intrinsic material
issues. When HTEs are exposed to high temperatures for
extended periods of time, the materials used for sub-
strates, die attach, wire bonding, and metal interconnects
all have to be chosen carefully and should have good high-
temperature properties. Some of the important properties
for HTEs packaging and interconnections include:

-  Materials used should have matching TECs.
-  Interfacial materials used should be chemically inert.
-  Interconnect metals should not be mixed if possible, to

avoid intermetallics.
-  Substrates should have high dielectric strength at high

temperature.

4.4 Design Techniques for High-Temperature
Applications  

Design for high-temperature applications cannot dis-
pense with circuit techniques to solve problems due to
high-temperature operation. By combining techniques
such as process technology, physical design, and layout
techniques cost effective and reliable high-temperature
devices and ASICs can be designed.

Above 200°C, the SOI and epi-CMOS combined with
conservative layout rules (e.g. guarding and interdigitized
structures) and techniques such as low power supply volt-
age, operating the devices into the zero-temperature coef-
ficient (ZTC) biasing point and scaling of transistor aspect
ratio offer cost effective solutions for implementing reli-
able high-temperature systems (Fallet et al. 1994;
Shoucair et al. 1984; Vermesan, 1997; Wu and Brown,
1991).

In the Aerospace market today, the SOI technology
coupled with the above high-temperature design tech-
niques are being used. There are currently several major
projects ongoing which are in various stages of develop-
ment, testing, and demonstration. The reliability testing of

components has been ongoing for several years. Data col-
lection of reliability at the component level has indicated
the ability to operate within specification for 5 years or
more at 225°C. These results have included thermal
cycling, package mechanical testing as well as accelerat-
ed temperature and voltage testing (Hunter, 2004; Lewis,
1998; Naefe, 1998).

In the industrial control and instrumentation arena,
high-temperature circuit techniques are used to overcome
the inherent drift and non-linearity of sensors, condition-
ing blocks (e.g. instrumentation amplifiers, A/D convert-
ers), and actuators due to temperature effects (Brusius,
1994; Bryzek, 1993). In low-temperature applications
inherent drift and non-linearity in the sensor due to tem-
perature effects are generally neglected. High-temperature
approaches such as sensor's scaling (Normann and
Livesay, 1998), removing of thermal drift of instrumenta-
tion amplifiers (Paine Instruments), and overcoming ther-
mal effects when controlling actuators using pulse-width
modulation (PWM) signals (Honeywell) were demon-
strated. 

Consequently, all "screw" it up and let industry and
market guide the way. 

5.  Market Overview

The world market for HTE components reached $148
million in 1995. Industry analysts estimate that this will
reach $1.5 billion by 2010 as shown in Table 6. The mar-
ket is currently quite a bit small; about $1billion, because
of component scarcity, component cost, the lack of semi-
conductor fabrication facilities capable of producing these
devices, and immature packaging and materials technolo-
gy.  It is highly expected that key drivers like well logging
equipment, aerospace, and automotive industries, plus
several niche applications will boost the HTE market. 

By temperature range, operation up to 200oC satisfies
most requirements currently. As the technology matures,

 1995 2000 2010 
Actual Market by Application Sector ($ million)  
Well Logging 
Equipment  

62 93 313 

Aerospace    6 38 221 
Automotive  73    274 848 
Other   7 31 118 
Total    148    436   1500 
By Temperature Range, as % of total  
Up to 200 oC 92 88 80 
200-300oC   8 11 12 
>300oC   0   2   8 
By Semiconductor Technology, as % of  total  
Si/SIO 88 86 83 
GaAs 12 13   9 
WBS   0   1   8 

Table 6.  The world market for high-temperature
electronics



53

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

applications at high temperatures will be enabled and are
expected to account for 20% of the market by 2010. Si-
based technologies dominate applications up to 200-
250oC. GaAs and wide bandgap semiconductors (SiC,
diamond and group III nitrides) will play critical roles
beyond 250oC, accounting for 17% of the market by
2010.

6.  Conclusions

Status and future prospects of high-temperature elec-
tronics have been reviewed. High-temperature electronics
are a key enabling technology for many applications in a
wide range of industrial sectors. Therefore, they have been
recognized as a strategically potential technology.
Development of high-temperature electronics is being
driven mainly by vertically integrated system organiza-
tions in strategic sectors such as oil and gas logging,
space, automotive, and communications along with small
specialist companies developing new semiconductor tech-
nologies. These electronics are based on SOI and wide
band-gap semiconductors like silicon carbide, diamond,
and oxides by virtue of their superior physical properties
compared to those of conventional technologies (Si,
GaAs). Modern systems require distributed electronics to
achieve adequate performance and accuracy, but conven-
tional components cannot handle high temperatures
because of severe derating and thermal wearout. The
major market opportunities will arise from incorporating
high-temperature electronics in subsystems/systems, as
opposed to high-volume component markets. Recently,
the technology has witnessed major advancements toward
systematic implementations. However, many technical
challenges are still pending and need to be surmounted.  

Acknowledgments

The authors wish to thank Sultan Qaboos University
(SQU) for providing the facilities and resources.

References

Bauer O., Auerbach J.G., Porst F., Roth A., Ruething R.
and Schilling, H., 2001, "6.5 kV-modules Using
IGBTs with Field Stop Technology," IEEE
Proceedings of the 13th  Int. Symposium on Power
Semiconductor Devices and ICs, pp. 121-124, Osaka,
Japan.

Bottner, T., 1991, "High-temperature Electronics for
Automobile, Aeronautical, Geothermal, Nuclear, and
Space," Proceedings of The 1st Int. High-temperature
Electronics Conference, pp. 77-82, Albuquerque,
NM.

Brown, D. M., 1994, "High-temperature Silicon Carbide
Planar IC Technology and First Monolithic SiC
Operation Amplifier IC," Proceedings of The 2nd Int.
High Temperature Electronics Conference,  pp. XI17-
XI22, Charlotte, NC.

Brusius, P., 1994, "Reliable High-temperature SOI
Process," Proceedings of The 2nd Int. High-tempera-
ture Electronics Conference, pp. 15-19, Charlotte,
NC.

Bryzek, J., 1993, "The Evolution of Smart Sensor and
Transducer Design," Sensors, pp. 12-22.

Cole, M.W., Joshi, P. C., Hubbard, C., Demaree, J. D. and
Ervin, M., 2002, "Thermal Stability and Performance
Reliability of Pt/Ti/WSi/Ni Ohmic Contacts to n-SiC
for High-temperature and Pulsed Power Device
Applications," J.  of Applied Physics, Vol. 91(6), pp.
3864-3868.

Eriksson, J., 2002, Silicon Carbide Microwave Devices,.
Publisher: Chalmers University of  Technology,
Sweden.

Fallet T., 1996, "A High-Temperature Voltage Regulator
Chip For Downhole Applications," Proceedings of the
3rd Int.  High-temperature Electronics Conference,
pp. 3-8, Charlotte, NC.

Fallet, T., Gakkestad, J. and Forre, J., 1994, "Application
Specific Integrated Circuits for High Temperature Oil
Well Applications," Proceedings of The 2nd Int.
High-temperature Electronics Conference,  pp. VII9-
VII14, Charlotte, NC.

Flandre, D. and Colinge, J. P., 1994, "High-temperature
Characteristics of CMOS Devices and  Circuits on
Silicon-on-Insulator (SOI) Substrates," Proceedings
of IX SBMICRO 94, pp. 777-786, Rio de Jeneiro.

Grzybowski, R., 1998, "Long Term Behavior of Passive
Components for High-temperature Applications-An
Update," Proceedings of the High-Temperature
Electronic Materials, Devices and Sensors
Conference, pp. 172-179, Albuquerque, NM.

Hasanuzzaman, M., Islam, S. K. and Tolbert, L. M, 2004,
"Effects of Temperature Variation  (300°-600°K) in
MOSFET Modeling in 6H Silicon Carbide," Solid
State Electronics, Vol. 48(1),  pp. 125-132.

Hunter, G. W., Neudeck, P. G., Xu, J., Lucko, D., Trunek,
A., Artale, M., Lampard, P., Androjna, D., Makel, D.,
Ward, B. and Liu,  C.C.,  2004, "Development of SiC-
Based Gas Sensors for Aerospace Applications,"
Materials Research Society Symposium Proceedings,
Vol. 815, pp. 287-297, San Francisco, CA, USA.

Ishii, S., Yasuoka, K. and  Ibuka, K., 2001, "Pulsed Power
Application Assisted by Power  Semiconductor
Devices," IEEE Proceedings of the 13th Int.
Symposium on Power Semiconductor Devices and
ICs, pp. 11-14, Osaka, Japan.

Johnson, R. W., Evans, J. L., Jacobsen P., Thompson, J. R.
and Christopher, M., 2004, "The  Changing
Automotive Environment: High-Temperature
Electronics," IEEE Transactions on Electronics
Packaging Manufacturing, Vol. 27(3), pp. 164-176.

Kodjak, D., 1993, "Emissions, Quantifying the Air
Quality Impact of EV Recharging," Green Car J.,
October Issue, pp. 116-120.

Kodjak, D., 1996, "EVs: Clean Today, Cleaner
Tomorrow," Technology Review, August issue,  pp.
66-67.



54

The Journal of Engineering Research Vol. 3, No. 1 (2006) 43-54

Lall., P.,  Pecht, M. and Hakim, E., 1997, Influence of
Temperature on Microelectronics and System
Reliability: A Physics of Failure Approach. CRC
Press, New York. 

Lee, B. T., Shin, J. Y., Kim, S. H., Kim, J. H., Han, S. Y.
and Lee, J. L., 2003, "Investigation of  Ti/Al and
TiN/Al Thin Films as the Stable Ohmic Contact for p-
Type 4H-SiC," J.  of Electronic Materials, Vol. 32(6),
pp. 501-509.

Lemnios, J., 1995, "Manufacturing Technology
Challenges for Low Power Electronics," Proceedings
of VLSI Technology Symposium, pp. 5-8, Kyoto,
Japan.

Lewis, T., 1998, "Military Aircraft Turbine Engine
Electronics and Requirements," Proceedings of The
4th Int. High-temperature Electronics Conference, pp.
1-23, Albuquerque, NM.

Ma, Y., Wang, W. L., Liao, K. J. and Kong, C. Y., 2002,
"Study on Sensitivity of Nano-Grain  ZnO Gas
Sensors," J. of Wide Bandgap Materials, Vol. 10, pp.
113-120.  

Madsen, L. D., 2001, "Formation of Ohmic Contacts to
Ti-SiC and Their Impact on Devices,"  J.  of
Electronic Materials, Vol. 30(10), pp. 1353-1361. 

Matin, I. H., 1998, "Experts urge All-out Push for Non-
Fossil Energy," Nature, November 19 issue.

Matsumoto, S., Hiraoka S. and  Sakai Y., 2001, "A High-
efficiency 5-GHz-band SOI Power MOSFET having
a Self-Aligned Drain Offset Structure," IEEE
Proceedings of the 13th Int. Symposium on Power
Semiconductor Devices and ICs, pp. 99-102, Osaka,
Japan.

Naefe, J., Johnson, W. and Grzybowski, R., 1998, "High-
temperature Storage and Thermal Shock Studies of
Passive Component Attach Materials," Proceedings
of The Fourth Int. High-temperature Electronics
Conference, pp. 68-78, Albuquerque, NM.

Normann, R. and Livesay, B., 1998, "Geothermal High-
temperature Instrumentation Applications,"
Proceedings of the 4th Int.  High-temperature
Electronics Conference, pp. 21-31, Albuquerque,
NM.

Ozpineci, B., Tolbert, L. M., Islam, S. K. and
Hasanuzzaman, M., 2002, "System Impact of SiC
Power Devices," Int.  J.  of High Speed Electronics
and Systems, Vol. 12(2), pp. 439-448. 

Patrick, F., McCluskey, Grzybowski, R. and Podlesak, T.,
1997, High-temperature Electronicsm.  CRC Press,
Inc., New York.  

Pinardi, K., 2003,"Modelling of High Power SOI Vertical
DMOS Transistors and Flip-chip Packages".
Doctoral Dissertation, Publisher: Chalmers
University of Technology, Sweden. 

Prelas, M. A., Ghosh, T. K., Loyalka, S. K. and Tompson,
R. V., 2002, "Hydrogen Storage in  Diamond Films,"
J.  of Wide Bandgap Materials, Vol. 10, pp. 99-111.   

Ryu, S., Kornegay, K. T., Cooper, J. A. and Melloch, M.
R., 1997, "6H-SiC CMOS Digital ICs Operating on a

5V Power Supply," IEEE Device Research Conf., pp.
38-39, Fort Collins, CO, USA.

Ryu, S., Kornegay, K.T., Cooper, J. A. and Melloch, M.
R., 1998, "Digital CMOS ICs in 6H-SiC Operating on
a 5V Power Supply," IEEE Trans. on Electron
Devices, Vol. 45(1), pp. 45-53. 

Saxena, V., Nong, J. S. and Steckl, A. J., 1999, "High-
Voltage Ni- and Pt-SiC Schottky Diodes Utilizing
Metal Field Plate Termination," IEEE Transactions
on Electron Devices, Vol. 46, No. 3, pp. 456-464.

Shahidi, G. G., 1993, "SOI for a 1-Volt CMOS Technology
and Applications to a 512-Kb SRAM with 3.5 ns
Access Time," Proceedings of IEDM, pp. 813-816,
Washington DC, USA.

Shoucair, F. S., Hwang, W. and Jam, P., 1984, "Electrical
Characteristics of Large Scale  Integration (LSI)
MOSFETs at Very High Temperatures, Part I:
Theory," Microelectronics Reliability, Vol. 24(3), pp.
465-485.

Shoucair, F. S., Hwang, W. and  Jam, P., 1984, "Electrical
Characteristics of Large Scale Integration (LSI)
MOSFETs at Very High Temperatures, Part II:
Experiment," Microelectronics Reliability, Vol. 24(3),
pp. 487-510.

Spitsyn, A. B., Tompson, R.V., Prelas, M. A. and. Ghosh,
T. K., 2002, "Charge Carriers Removal from 4H-
SiC Using Field Enhanced by Optical Activation
Diffusion Method," J.  of Wide Bandgap Materials,
Vol. 10, pp. 89-98.

Spitz, J., Melloch, M. R., Cooper, J. A. and  Capano, M.
A., 1998, "High-Voltage (2.6 kV) Lateral DMOSFETs
in 4H-SiC," IEEE Electron Device Letters, Vol. 19,
pp. 100-107. 

Sims, P. E., 1996, "High-temperature Electronics for
Distributed Control Systems,"  Proceedings of The
3rd Int. High-temperature Electronics Conference, pp.
X9-15, Albuquerque, NM.

Tolbert, L. M., Ozpineci, B., Islam, S. K. and Peng, F. Z.,
2003, "Impact of SiC Power Electronic Devices for
Hybrid Electric Vehicles," J.  of Passenger Cars:
Electronic and Electrical Systems, pp. 765-771.

Touati, F. and Saji, M., 1999, "Electrical Properties and
Interface Chemistry in Ti/3C-SiC Contact System,"
Special Issue of the IEEE Transactions on Electron
Devices on Silicon Carbide, Vol. 46(3), pp. 186-189. 

Vermesan, O., 1997, "ASIC Design for High-Temperature
Applications," Proceedings of the 2nd Int. High-
Temperature Electronics Conference, Invited Paper,
pp. 1-7, Charlotte, NC.

Ziegler, K. J., Lyon., D. M., Holmes, J. D., Erts, D.,
Polyakov, B., Svensson, K., Olin, H. and  Olsson, E.,
2004, "Nanomechanical Non-volatile Memory
Element," Applied Physics Letters, Vol. 84(20), pp.
4074-4076.

Wu, K. and Brown, R. B., 1991, "High-Temperature
Design Rules," Proceedings of the 1st Int. High
Temperature Electronics Conference, pp. 267-272,
Albuquerque, NM.