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
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 hydr
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
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
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. Ass
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
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 101
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. Ass
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 )
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 p
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 )
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 Diff
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
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
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
v
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 re
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
Bui
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-Recombinati
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
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 Concentra
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 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
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
EE339 Semiconductor material and devices I, Homework #1 (due by Sept 16)
1) (15 points) Determine the number of atoms per unit cell in a
a. Face-centered cubic structure
8 corner atoms x 1/8 =1 atom
6
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 101
EE 339 Semiconductor materials and devices I
Description
The crystal structure of solids. Introduction to quantum mechanics and quantum theory of
solids. Charge carriers in semiconductors. Carrier tra
X-Ray Methods
09/30/2006 01:50 PM
X-Ray Methods
There are three different experimental methods for x-ray diffraction that we are going to look at:
The Laue method, the rotating crystal method and the
Reciprocal Lattice
09/30/2006 01:49 PM
Reciprocal Lattice
A reciprocal lattice of a crystal structure is a set of vectors denoted by K that satisfies the
constructive interference condition, i.e.
. He
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
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
PN Junction Diode
Space-charge Region
When a slab of P-type semiconductor and a slab of N-type
semiconductor are brought together, a PN junction is formed.
(not a practical way of forming a device)
Fo
Fabrication Technology
Wafers vs. chips
A chip 10-100 mm2 in size may contain up to several
million devices.
Fabrication Technology
Bulk crystal growth Czochralski method
(vertical pull)
Fabrication T
Carrier Statistics
Density of States
Density of states (DOS), N(E), is the number of states per
unit energy and per unit volume.
For a 3D crystal, DOS is expressed as
N (E)
8m
*
2
2 h
3/ 2
E 1/
Carrier Processes
Drift Velocity and Carrier Mobility
If a constant voltage is connected to the two sides of a
semiconductor chip, an constant electrical field E is created
in it. The field acts upon