Semiconductor Devices (EE 482 & EE 539A)
Instructor Contact Information:
M. P. Anantram (Anant)
EE Building, Room # M218
Phone: 206-221-5162
E-mail: [email protected]
Instructor Office Hours and Location: Wednesday 11 am noon, EE Bldg, Room #M218
TA Contact In
Lecture Note 7: BJT
Derivation of current-voltage characteristics
Example of current voltage characteristics
Performance metrics
Emitter injection efficiency
Base transport factor
Common base dc current gain
Common emitter dc current gain
Summary of desig
Lecture Note 1: Crystal Properties and
Growth of Semiconductors
1) Describe a semiconductor
2) Perform simple calculations on crystals
3) Basics of growth (read on your own from text)
Basics of semiconductor
Materials that have electrical conducti
Lecture Note 4: Basics of semiconductor
concepts
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
What is a semiconductor
Convention to represent energy bands
Direct and indirect semiconductors
Fermi function: Probability of occupancy
Concept of hole
Mass of hole
Wave vect
Lecture Note 5: Drift and Diffusion
Currents
Continuity equation
In-flow and Out-flow of current
Generation and Recombination
Particle and electrical current densities
Mechanisms for current flow: Drift and Diffusion
Drift and Mobility
Diffusion
Total cur
Lecture Note 2: Quantum Mechanics
Introduction
1) Historical Motivation for Quantum Mechanics
a. Plancks Hypothesis
b. De Broglie Principle
c. Youngs double slit experiment
d. Energy levels of Hydrogen atom and Bohrs hypothesis
e. Tunneling
2) Schrodinger
Lecture Note 5: Drift and Diffusion Currents
Continuity equation
In-flow and Out-flow of current
Generation and Recombination
Particle and electrical current densities
Mechanisms for current flow: Drift and Diffusion
Drift and Mobility
Diffusion
Total cur
DIODES
p-type
n-type
V
Electrostatics - Qualitative view
p-type
n-type
V
p-type
When separated, the blocks are neutral
n-type
When the blocks join, electrons diffuse to
the p-side and holes diffuse to the n-side.
This builds up an electric field which
pre
1
Electronic Materials
Electrical characterization of materials
Insulators
> 10 cm
e.g. Diamond = 10 cm
Conductors < 10 cm
e.g. Copper = 3 10 cm
Semiconductors in between
Elemental semiconductors (e.g. Si)
Compound semiconductors (e.g. GaAs)
Semico
Lecture Note 3: Velocity, Force and
Effective Mass
1) Velocity of an electron in a material with a band structure E (k )
2) Relationship between force and time evolution of wave vector k .
3) Effective mass of electrons.
Lecture Note 3
M. P. Anantram,
HW 8
(due Wed Nov 19 )
1) In a PNP BJT with NE=1E+17 cm-3, NB=1E+14 cm-3 , NC=1E+14 cm-3 with DB 35cm 2 / s
DE DC 12cm 2 / s , E 1 s , B 1 s and C 1 s , and base width of 4m , what are the
emitter injection efficiency, base transport factor and common emi
HW 2
(due in class on October 8)
PiB (Particle in Box)
1) Discuss two important important differences between the classical and quantum mechanical
solutions for the PiB problem. One difference should address the probability of finding a
particle in the bo
HW 1
(due in class on October 1)
Planes and directions
1) Draw the (423) plane and the [423] direction in a cubic lattice.
2) Identify the plane drawn in the figure below.
c
-2b
y
a
x
Lattice vectors of the
cubic lattice are a, b
and c along the x, y
and
HW 3
(due in class on October 15)
Force, wave vector and velocity
1) Consider the two different E(k) relationships shown below (SI units):
2
Indirect Bandgap Semiconductor: E =
k2
5 1031 kg
2
+ 0.5eV (CB) and E = 0.5eV
k2
5 1031 kg
(VB)
m
Graphene: E = 4
HW 4
(due in class on October 22)
1. Consider a semiconductor with a bandgap of 0.66eV . If the Fermi energy is 26meV above the
valence band edge. Plot the probability of finding (i) an electron in the conduction band and
(ii) hole in the valence band. Pl
HW 7
(please submit between Nov 13-15, slip under my door)
1) (a) Why is it desirable to have very high doping in a Zener diode? (b) In Zener diodes, how
does the breakdown voltage change with semiconductor (Si, Ge, GaAs) bandgap?
2) Consider a PN junctio
HW 10
(Due Fri Dec 5)
This HW is optional and can be used to replace your lowest HW score. There are two interesting issues that this HW
problem addresses. Even if you do not submit this HW, please think about he two issues.
1) Qualitatively describe (i)
HW 5
(due in class on October 29)
1. The electron and hole densities in two different pieces of semiconductor are shown below.
Draw plots of the electrical current densities due to diffusion only for the carrier whose density
is given in the plots. For si
1
Electronic Materials
Semiconductor Materials
Semiconductor Bandgap
(eV)
C (diamond)
Si
Ge
Sn
GaAs
GaN
InP
BN
SiC
CdSe
5.47
1.12
0.66
0.082
1.42
3.49
1.35
7.50
3.26
1.70
4
5
Periodic System
a
a
a
a
a
a
a
a
a
A primitive cell
a
a
a
a
a
a
A primitive cell