Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 4 pps
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 1 doc
... ⇒ 4 probes
© H.L. Tuller-2001
For R
9
3.225
9
Equation of Motion - Impact of Collisions
Assume:
• probability of collision in time dt = dt/τ
• time varying field F(t)
v(t+dt) = ( 1- dt/τ) ... L/Wt = ρ L/A ⇒ρ(οhm-cm)
σ = 1/ρ ⇒ σ (οhm-cm)
-1
⇒σ (Siemens/cm)
(Test your dimensions: σ=E/j=neµ)
Ohms/square ⇒ Note, if L=W, then R= ρ /t independent
of magnitude of L...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 5 ppt
... Eg=1.1eV, and let µ
e
and µ
h
be approximately equal at 1000cm
2
/V-sec (very good Si!).
σ~10
10
cm
-3
*1.602x10
-1 9
*1000cm
2
/V-sec=1.6x10
-6
S/m, or a resistivity ρ of about 10
6
ohm-m max. ... Si: . 046 eV
•
P donor in Si: 0. 044 eV
•
As donor in Si: 0. 049
© E. Fitzgerald-1999
3.225
18
The Power of Doping
• Can make the material n-type or p-type: Hydrogeni...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 10 pps
... 13
10
-7
10
-6
10
-5
10
-4
Y-cut
σ
0
= 2.1 S cm
-1
E
A
= 105 kJ mol
-1
10
4
/T [1/K]
σ
[S cm
-1
]
900 800 700 600 500
T [°C]
13
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13
© H.L. Tuller-2001
Gas Sensors and MEMS ...
•Smart sensors
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14
© H.L. Tuller-2001
Microhotplate
7
4
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7
© H.L. Tuller-2001
0 5 10 15 20 25 30 35
1E-5
1E -4
1E-3
0,01
0,1
T = 850°C
X=0.03
X=0.0...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 9 pps
... (Ωcm)
-1
)
T = 800 °C
log(pO
2
/ bar)
0.995 1,005
-1 6 -4 0
-5
-4
-3
-2
-1
0
1
donor
acceptor
-2 0 -1 2 -8
donor doped
acceptor doped
2
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Designer Wavelengths
Variation of ... Wavelengths
Variation of band-gap energy with composition x of In
1-x
Ga
x
As.
© H.L. Tuller, 2001
3.225
16
Band-Gap Colors
Mixed crystals of yellow cad...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 3 pot
... (xrays) can be ‘particle-like’
• DeBroglie
– matter can act like it has a ‘wave-nature’
• Schrodinger, Born
– Unification of wave-particle duality, Schrodinger
Equation
Wave-particle Duality: ... E. Fitzgerald-1999
3.225
18
Ψ must be able to represent everything from a particle to a wave (the two
extremes)
Unification: Wave-particle Duality
wave
particle
(
tkxi
Ae
ω−
=Ψ
k and p kn...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 6 pps
... when you join these together?
© E. Fitzgerald-1999
3.225
12
-
-
+
+
+
+
Holes diffuse
Electrons diffuse
+
+
+
+
-
-
-
-
+
+
+
+
-
-
+
+
+
+
An electric field forms due to ... 3.225
11
The p-n Junction (The Diode)
• Note that dopants move the fermi energy from mid-gap towards either the
valence band edge (p-type) or the conduction band edge (n-t...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 8 pdf
... metastable relative positions of
positive and negative ions
© E. Fitzgerald-1999
3.225
4
Ferroelectrics
Applications
• Capacitors
• Non-volatile memories
• Photorefractive materials
© H.L. Tuller, ...
−
=
1
© E. Fitzgerald-1999
9
3.225
11
Interaction of the d orbitals of a central ion with six ligands in
an octahedral arrangement.
Octahedral Environment of Tra...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 4 pps
... are:)
n=1,2,3,…
=0,1,2,…,n-1
m
l
=- , - +1,…,0,…, ,
(m
s
=+ or - 1/2)
l
l
l
l
0
-1 3.6eV
U(r)
© E. Fitzgerald-1999
)
in
-1
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9
Diffraction Picture of the Origin of Band Gaps
Probability Density=probability/volume ... Electron Model
© E. Fitzgerald-1999
5
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5
Metals and Insulators
•E
F
in mid-band area: free e-, metallic
•E
F
near band edge
–E
F...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 11 potx
...
HAMABA
B
B
2
2
4
4
444 ~
=
Φ
=
===Φ
L increased by ~χ due to
magnetic material
Material Type
χ
Paramagnetic +10
-5
-1 0
-4
Diamagnetic -1 0
-8
-1 0
-5
Ferromagnetic ...
=
14
41
MKS:
B = µ
0
(H+M) = µ
0
nI + µ
0
M
µ
r
= B/ µ
0
H = 1 + (M/H) = 1 + χ
m
Magnetic Permeability and Susceptibility
4
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4
© E. Fitzgerald-199...
Materials Science and Engineering - Electronic and Mechanical Properties of Materials Part 2 pot
... x 10
14
Hz)
λ = c/ν = 40 0 nm
k=2π/ λ = 1.57 x 10
7
m
-1
ω = 2 πν = 4. 71 x 10
15
s
-1
After Livingston
ε
)
ε
(kx-
)
ε
6
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• Scaling of Si CMOS includes conductivity engineering ... e
-i(kx-ωt)
are all waves
e
-i(kx-ωt)
is the complex one and is the most general
real
imaginary
A
Acosθ
iAsinθ
θ
e
iθ
=cosθ+isinθ
© E.A. Fitzgerald-1999
1
3.225...
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