Class note#19
Topics covered in this class
z Fabrication Technology
Introduction
Silicon growth: wafer preparation
Device Fabrication
Oxidation
Etching
Diffusion
Ion implantation
2
Introduction: Microprocessor Chips
Conductive layer
Top protective
Class note#9
Topics covered in this class
z Extrinsic Semiconductors
N-type semiconductor
P-type semiconductor
z Thermal equilibrium
2
Extrinsic Semiconductors
z Extrinsic semiconductors are formed by the addition of
small amounts of selected impurities
Class note #4: Basic Quantum Theory
Topics covered in this class
z Wave Mechanics
z Heisenbergs uncertainty principle
z Schrodingers Equation
Application to the potential Well
2
Wave Mechanics
z Diffraction pattern was observed when beams of electrons
we
Class note#5
Topics covered in this class
z Application of Schrdinger's equation to the hydrogen
atom
z Energy level splitting
z Energy band formation
2
Application of Schrdingers equation
to the hydrogen atom
z The limitation of Bohrs theory of the hydro
EE339 Semiconductor material and devices I, Homework #5 (due by Dec 9)
Question 1.
Certain PN Junctions have a doping profile that is known as linearly graded, as shown in
the figure, such that (ND-NA)=ax in the depletion region. Assume symmetrical doping
EE339 Semiconductor material and devices I, Homework #5 (due by Dec 9)
Question 1.
Certain PN Junctions have a doping profile that is known as linearly graded, as shown in
the figure, such that (ND-NA)=ax in the depletion region. Assume symmetrical doping
EE339 Semiconductor material and devices I, Homework #4 (due by Nov 6)
Question 1.
Consider a homogeneous GaAs semiconductor at T=300K and electron mobility = 7500
and hole mobility =310 cm2 /V-s. Assume that the mobilities are constant with doping.
a) Fo
Semiconductor Materials and Devices (EE339)
ELECTRICAL ENGINEERING DEPARTMENT
CITY COLLEGE OF NEW YORK
Exam #1 Sept 25, 2008
Name (Last, First name):
-Note #1: Please print your name.
Note #2: please provide a brief explanation of your answers to all answ
EE339 Semiconductor material and devices I, Homework #3 (due by Oct 21)
Question 1.
Based on the effective density of states and band gap energy at T=300K
Semiconductor
Si
Ge
GaAs
Nc (cm-3)
3.22 x 1019
1.03 x 1019
4.21 x 1017
Nv (cm-3)
1.83 x 1019
5.35 x
Class note#10
Topics covered in this class
z Extrinsic Semiconductor
z Thermal Equilibrium
z Densities of carriers in extrinsic semiconductors
Charge neutrality
Additional expressions for n0 and p0
z Fermi level in extrinsic semiconductors
2
Extrinsic S
Class note#11
Topics covered in this class
z Review from the last class
z Carrier Process:
Velocity Limitation
Thermal Velocity
Collisions and Scattering
2
Carrier Process
z Electrons and holes as the current carriers in a
semiconductor
z Electrons exi
Class note#6
Topics covered in this class
z
z
z
z
Mathematical model of band formation
Kronig-Penny Model
Direct and indirect semiconductor
Covalent bond model
2
Potential Energy in a crystal
Lattice constant
The electronic potential energy V(x)
V(x)
For
Class note#13
Topics covered in this class
z Review from the last class
z Carrier Process:
Drift Current and Conductivity
Resistivity and Resistance
Diffusion
Carrier Currents
2
Mobility
qE x c
vd =
mn*
vd = n E x
z The drift velocity of electron (or
Class note#16
Topics covered in this class
z Review from the last class
z P-N Junction Diode:
Currents in Diode
Motion of Carriers with bias applied
Conditions with forward bias
Conditions with reverse bias
2
Conditions in the diode with voltage
appli
Class note#15
Topics covered in this class
z Review on the exam
z P-N Junction Diode:
Analytical Relations at Equilibrium
Electrostatics of the space charge region
Constancy of the Fermi Level
Built-in voltage in terms of Fermi potential
Built-in vol
Class note#14
Topics covered in this class
z Review from the last class
z Carrier Process:
Recombination and Generation
Rates of R-G
Direct Generation-Recombination
Indirect Generation-Recombination
Low level Injection and Recombination
Analytical R
3
4
5
6
7
8
9
10
The periodic potential
introduces a perturbation
that distorts the freeparticle solution.
The modification is
greatest at the lower
energies with the two
solutions essentially
merging at the higher
energies. This seems
reasonable from an
Class note#12
Topics covered in this class
z Review from the last class
z Carrier Process:
Collisions Effects
Drift Velocity
Collisions and Energy Exchanges
Mobility
Effects of Impurity Concentration and Temperature
on Mobility
Expressions for the M
Class note#8
Topics covered in this class
z Review from the last class and exam #1
z Intrinsic and Extrinsic semiconductor
Density of States
Fermi-Dirac Distribution Function
2
Types of charges in semiconductors
z Hole
Mobile Charge Carriers
They contri
EE339 Semiconductor material and devices I, Homework #4 (due by Nov 6)
Question 1.
Consider a homogeneous GaAs semiconductor at T=300K and electron mobility = 7500
and hole mobility =310 cm2 /V-s. Assume that the mobilities are constant with doping.
a) Fo
EE339 Semiconductor material and devices I, Homework #2 (due by September 23)
One dimension time-independent Schrdinger equation can be written as follows:
h 2 2 ( x)
+ V ( x ) ( x ) = E ( x ) ( x )
2
2m
x
Let the solution of wave function:
( x) = u ( x
Semiconductor Materials and Devices (EE339)
ELECTRICAL ENGINEERING DEPARTMENT
CITY COLLEGE OF NEW YORK
Exam #2 Nov 11, 2008
Name (Last, First name):
-Note #1: Please print your name.
Note #2: please provide a brief explanation of your answers to all answe
Crystalline State
09/30/2006 01:48 PM
Crystalline State
Solids are classified according to regularity and structure of their building blocks, typically atoms
and can be the following:
1. Amorphous No periodic structure at all. All constituent atoms are di
Recombination-Generation
09/30/2006 01:51 PM
Recombination-Generation
The generation and recombination of electrons and holes in a semiconductor play an important role in their
electrical and optical behavior. These processes are defined as:
Recombination
Bravais Lattice
09/30/2006 01:48 PM
Bravais Lattice
In 1848, Auguste Bravais demonstrated that there are fourteen possible point lattices and no more.
For his efforts, the term bravais lattice is often used in place of point lattice. The fourteen bravais
Introduction to Quantum Mechanics
09/30/2006 01:50 PM
Introduction to Quantum Mechanics
Quantum Mechanics arose as a result of problems that were becoming evident with classical physics in the
late 1800s and early 1900s. These problems are as follows:
1.
Ideal Diode Current-Voltage Characteristics
09/30/2006 01:52 PM
Ideal Diode Current-Voltage Characteristics
Qualitative View
Thermal Equilibrium
As we have said before, the electron and hole current across the PN junction in thermal equilibrium is zero.
A
X-Ray Diffraction and Reciprocal Lattice
09/30/2006 01:49 PM
X-Ray Diffraction and Reciprocal Lattice
Up until this point, the structure of crystals have been studied and classified because of its extreme
importance to almost every mechanical and electric
Blochs Theorem
09/30/2006 01:50 PM
Periodic Potential Energy of Electrons in a Crystalline Environment
The potential energy of electrons in a crystal are a result of the positively charged atomic cores producing a
coulombic attraction. All the electron-el
Miller Indices
09/30/2006 01:49 PM
Miller Indices
The use of Miller indices for describing planes and directions within a crystal lattice is very
common. To obtain the Miller indices describing a plane, you use the following four-step procedure given
by P