Engineering materials for electrical engineers

ECE 331: Introduction to Materials for
Electrical Engineers
Course Objective
Introduce fundamental concepts in Materials
Introduce

fundamental

concepts

in

Materials
Science and how they are used in ECE
You will learn about:
• material structure
• how structure dictates properties
• how electronic & physical properties are related
•

how

electronic

&

physical

properties

are

related
This course will help you to:
• use materials properly
•

use

materials

properly
• realize new design opportunities with materials
• understand the physics of semiconductor devices
ECE331 Wi11 lecture 1
ECE 331 – Intro to Materials for ECE
Materials in ECE are: semiconductors, metals (e.g.
Al t t ) l ( l t f LED )
Al
con
t
ac
t
s
)
, po
l
ymers
(
e.g. encapsu
l

an
t
s
f
or
LED
s
)

and insulators (ceramics such as silicon dioxide in
FETs
)
)
Materials in ECE are single crystals, polycrystals,
hl d tt
amorp
h
ous
l
ayers an
d
nanos
t
ruc
t
ures
Si (silicon) is
NOT
the only semiconductor (though
Si

(silicon)

is

NOT
the

only

semiconductor

(though

Si electronics is the world’s largest manufacturing
industry), but it is the most important one and will
i!
ECE331 Wi11 lecture 1
rema
i
n so
!
ECE 331 – Intro to Materials for ECE
III-V examples
GaAs
InP
InAs
AlGaAs
AlGaAs
InGaAs

InGaAsP
GN
G
a
N
InGaN
ECE331 Wi11 lecture 1
III -V
•Know your periodic table!
•Find your old chemistry notes!
Materials Roadmap for Device Technologies: the
Bandgap vs Lattice Constant Relationship
III
-
V electronics
ECE applications
are
expanding across
III
V

electronics
CD Lasers
Fiber pump lasers
Space solar
expanding

across

this entire space!

CMOS BiCMOS
CMOS
,
BiCMOS
,
Terrestrial solar,
Power CMOS
Telecomm
Optoelectronics
thermophotovoltaics
ECE331 Wi11 lecture 1
TECHNOLOGY ROADMAPS:
New Age for ECE Materials and opportunities
•
Electronics:
Roadmaps are calling for unusual properties not
obtainable using conventional materials or processes
•
Electronics:
- Nanoscale patterning
- optical interconnects
- speed enhancing materials
•
Optoelectronics:
Optoelectronics:

- tunable light emission/detection wavelengths
- seamless integration with electronic systems
• Alternative Energy:
- clean, renewable, cheap, safe, autonomous

ECE331 Wi11 lecture 1
- Biocompatiblity and medicine
The Materials Selection Process
1. Pick Application Determine required Properties
Properties: mechanical, electrical, thermal,
magnetic, optical, deteriorative.
2. Properties Identify candidate Material(s)
Material: structure, composition.
3. Material Identify required Processing
Processing: changes
structure
and overall
shape
Processing:

changes

structure
and

overall

shape
ex: casting, sintering, vapor deposition, doping
forming, joining, annealing.
ECE331 Wi11 lecture 1
ELECTRICAL
• Electrical Resistivity of Copper:
A
dapted from Fi

g
. 18.8, Callister 7e.
6
g
(Fig. 18.8 adapted from: J.O. Linde,
Ann Physik 5, 219 (1932); and
C.A. Wert and R.M. Thomson,
Physics of Solids, 2nd edition,
McGraw-Hill Company, New York,
1970 )
4
5
y, r
m)
1970
.
)
2
3
e
sistivit
0
-8
Ohm-
1
2
R
e
(1
0

0
• Adding “impurity” atoms to Cu increases resistivity.
T (°C)
-200 -100 0
0
ECE331 Wi11 lecture 1
• Deforming Cu increases resistivity.
THERMAL
• Space Shuttle Tiles:
Silica fiber insulation
offers low
heat conduction
• Thermal Conductivity
of Copper:
decreases when you add zinc!
offers

low

heat

conduction
. -
decreases

when

you

add

zinc!
i
ty
400
Adapted from chapter-
opening photograph,
o
nductiv
i
/
m-K)
300
200
Chapter 19, Callister
7e. (Courtesy of
Lockheed
Missiles and Space
Company, Inc.)
h
ermal C
o
(W
/
100
0
0
10
20
30

40
Adapted from
Fig. 19.4W, Callister
6e. (Courtesy of
Lockheed Aerospace
CS
Adapted from Fig. 19.4, Callister 7e.
(Fig. 19.4 is adapted from Metals Handbook:
Pro
p
erties and Selection: Nonferrous allo
y
s
Composition (wt% Zinc)
T
h
0
10
20
30
40
ECE331 Wi11 lecture 1
C
eramics
S
ystems,
Sunnyvale, CA)
(Note: "W" denotes
fig. is on CD-ROM.)
py

and Pure Metals, Vol. 2, 9th ed., H. Baker,
(Managing Editor), American Society for
Metals, 1979, p. 315.)
100mm
MAGNETIC
• Magnetic Permeability
vs. Composition:
• Magnetic Storage:
Recording medium
Adding 3 atomic % Si
makes Fe a better
recordin
g
medium!
is magnetized by
recording head.
g
z
ation
Fe+3%Si
F
M
agneti
z
F
e
Adapted from C.R. Barrett, W.D. Nix, and
A.S. Tetelman, The Principles of
Engineering Materials
,Fig.1

-
7(a), p. 9,
Fig. 20.23, Callister 7e.
(Fig 20 23 is from J U Lemke
MRS Bulletin
Magnetic Field
M
ECE331 Wi11 lecture 1
Engineering

Materials
,

Fig.

1
7(a),

p.

9,
1973. Electronically reproduced
by permission of Pearson Education, Inc.,
Upper Saddle River, New Jersey.
(Fig
.
20
.
23

is

from

J
.
U
.
Lemke
,
MRS

Bulletin
,
Vol. XV, No. 3, p. 31, 1990.)
OPTICAL
• Transmittance:
Aluminum oxide may be transparent, translucent, or
opaque depending on the material structure.
sin
g
le cr
y
stal
polycrystal:
low
p
orosit
y
polycrystal:

hi
g
h
p
orosit
y
gy
py
gp y
Adapted from Fig. 1.2,
Callister 7e.
(Specimen preparation,
P.A. Lessing; photo by S.
Tanner )
ECE331 Wi11 lecture 1
Tanner
.
)
Photovoltaics and the role of materials
ECE331 Wi11 lecture 1
ECE331 Wi11 lecture 1
Conversion of radiant heat to electricity:
Thermo
p
hotovoltaics
Interconnect
Grid Finger
Front Contact
p
n InPAs window

p InPAs BSF
Si
IltiIP
n InPAs Buffer
p/n InGaAs TJ
n/p InGaAs
Emitter/Bas
e
S
em
i
-
I
nsu
l
a
ti
ng
I
n
P
SiN/Gold Back Surface Reflector
23
SEM Micrograph Of Processed Ternary
MIM Structure
19
20
21
22
23

f
iciency (%)
26.7°C
26.7°C
25.6°C
• Efficiency ~18%
• With addition of a a front
surface filter
15
16
17
18
19
System Ef
f
25.6°C
surface

filter

– 0.9 W/cm
2
power density
- h = 20.6% at a radiator
temperat re of 1058
°
C
ECE331 Wi11 lecture 1
850 900 950 1000 1050 1100
Radiator Temperature (°C)

temperat
u
re

of

1058
°
C
.
Wide Bandgap Semiconductors – GaN:
Ener
gy
-Efficient Solid State Li
g
htin
g

(
SSL
)
gy
gg()
• Al-Ga-In-N spans uv-blue-green-red-near ir spectrum
50% of elec used by lighting:
National SSL Initiative: by 2020:
• save $115B
ECE331 Wi11 lecture 1
50%

of

elec
.
used

by

lighting:
• eliminate 258M metric ton of C
emission
SUMMARY
• Use the right material for the job
Course Goals:
•

Use

the

right

material

for

the

job
.

• Understand the relation between properties,
structure, and processing.
• Recognize new design opportunities offered
•

Recognize

new

design

opportunities

offered
by materials selection.
• Appreciate the relationship between devices
•

Appreciate

the

relationship

between

devices
,
their characteristics and their constituent materials
ECE331 Wi11 lecture 1