NMJ20603 Semiconductor
Physics
Lecture 01: Introduction
Sources
The contents is largely taken from Lecture Notes:
Assoc. Prof. Dr. Foo Khai Long
Dr. Nur Hamidah Abdul Halim
Dr. Noraini Othman
Text Books
Course Content
Overview
Introduction of semiconductor devices and technology.
Part 1
SEMICONDUCTOR PHYSICS
1. Energy bands and Carrier Concentration in Thermal Equilibrium
Semiconductor materials, basic crystal structure and growth techniques, valence bonds and energy bands, intrinsic carrier concentration, donors
and acceptors.
2. Carrier Transport Phenomena
Carrier drift and carrier diffusion, generation and recombination process, and continuity equation Thermionic emission process tunneling
process, and high-field effects.
Part 2
SEMICONDUCTOR DEVICES
3. p-n junction
Basic fabrication steps, thermal equilibrium condition, depletion region and capacitance, and C-V characteristics
Charge storage and transient behavior, junction breakdown, and heterojunction.
4. Bipolar Transistor
The transient action, static characteristics of bipolar transistor, frequency response and switching of bipolar transistor, and the heterojunction
bipolar transistor.
5. MOS Diode
The MOS diode fundamentals, basic operation, Flat band condition
6. MOSFET and Related Devices
MOSFET on insulator, MOS memory structures, and the power MOSFET
Lecturers
Ts. Dr. Nurjuliana
Juhari,
FKTEN
Assoc. Prof. Ir. Dr.
Mohd Khairuddin
Md Arshad,
FKTEN
Course Outcomes (CO)
01
02
03
CO1: Ability to apply the
theory of semiconductor
physics and basic operation
of semiconductor devices.
CO2: Ability to analyse the
semiconductor devices and
properties, related to
engineering fundamental in
terms of its problems and
performances.
CO3: Ability to evaluate
semiconductor operation in
terms of its enhancement
and problems related to
advanced semiconductor
technology.
Assessment
Type of Assessment
Week
Marks
W6
W14
W7
W13
40 %
Exam week
60%
Continuous Assessment (CA)
Assignment 1
Assignment 2
Test 1
Test 2
Final Examination
Answer all questions
Total
100%
References
Texts Book:
• D.A. Neamen (2012), Semiconductor
physics and devices : basic principles,
4th edition, international edition,
McGraw-Hill 2012. ISBN:
9780071089029
• S M Sze & M K Lee (2013),
Semiconductor devices : physics and
technology, 3rd edition, International
Student Version. John Wiley & Sons.
ISBN: 9780470873670
Acknowledgement
This presentation was largely taken from;
•
EMT471 Semiconductor Physics prepared by Dr. Syarifah
Norfaezah Sabki
•
EMT471 Semiconductor Physics prepared by Dr. Noraini Othman
•
EMT271 Semiconductor Fundamentals prepared by Dr.
Nurhamidah Abdul Halim
•
EMT272 Semiconductor Fundamental prepared by Assoc. Prof. Dr.
Foo Kai Long
Semiconductor Material
• Semiconductors are materials which have a conductivity
between conductors (generally metals) and nonconductors or
insulators (such as most ceramics).
• Semiconductors can be pure elements, such as silicon or
germanium, or compounds such as gallium arsenide or
cadmium selenide or alloys like ternary and quaternary.
• Ability to conduct electrical current, and they can be regulated
in the amount of their conductivity.
• Si is most widely used – easily obtained.
• Early developments semiconductor – 1600 to 1800.
Semiconductor Material
• The study of semiconductor materials
since 19th century.
• Early 1950s – Germanium (Ge) was the
major semiconductor material.
• Early 1960s, Si has become a practical
substitute with several advantages:
i.
better properties at room
temperature,
ii.
can be grown thermally – high quality
silicon oxide,
iii.
Lower cost, and
iv.
Easy to get, silica & silicates
comprises 25% of the Earth’s crust.
Compound Semiconductor
Types of compounds:
i.
binary compounds
o
combination of two elements.
o
i.e GaAs is a III – IV.
ii.
ternary and quaternary compounds for special
applications purposes.
o
ternary compounds, i.e alloy
semiconductor AlxGa1-xAs (III – IV).
o
quaternary compounds with the form
of AxB1-xCyD1-y , so-called combination
of many binary & ternary compounds.
o
more complex processes.
GaAs – high speed electronic & photonic
applications
Semiconductor Material
GENERAL
CLASSIFICATI
ON
EXAMPLE
SYMBOL
NAME
Element
Si
Ge
Silicon
Germanium
Binary
compound
(III – V)
GaN
GaP
GaAs
InP
Gallium Nitride
Gallium Phosphide
Gallium Nitride
Indium Phosphide
Ternary
compound
Quaternary
compound
AlxGa1-xAs
AlxIn1-xAs
AlxGa1-xAsySb1-y
Aluminum Gallium Arsenide
Aluminum Indium Arsenide
Aluminum gallium arsenide
antimonite
Conductivity,𝜎 =
!
"
Semiconductor Devices: Basic Device Building Block
M
S/C
p – type S/C n – type S/C
(1) Metal – semiconductor interface
(2) p – n junction
oxide
S/C A
S/C B
(3) Heterojunction interface
M
S/C
(4) MOS interface
Basic Device
Building
Block
•
1. Metal-semiconductor interface
•
intimate contact between a metal and
a semiconductor
•
first semiconductor device ever
studied (1874).
•
used as rectifying contact.
•
MESFET.
•
2. p-n junction
•
form between p-type s/c and n-type
s/c.
•
key building block for most s/c devices.
•
p-n junction theory – foundation of
the physics of s/c.
•
p-n-p bipolar transistor (1947).
•
p-n-p-n called thyristor.
• 3. Heterojunction interface
• interface between two dissimilar
s/c, i.e GaAs + AlAs à
heterojunction.
• the key components for highspeed and photonic devices.
• 4. Metal-Oxide-Semiconductor
(MOS) structure
• a combination of metal-oxide
interface and oxidesemiconductor interface.
•
MOSFET (MOS field-effect
transistor) – most important
device for advanced IC.
IC Evolution
1960
1971
1954
FIRST
Intel Micro
First Single PLANAR
Crystal INTEGRATED processor
Silicon CIRCUIT (IC)
1874 (Braun)
Metalsemiconduct
or contact
(detector)
1952
First Single
Crystal
Germanium
2000 ++
1975
First PC
1958 (TI)
First IC Device
1947 (Bell Lab)
First Transistor
Metal Oxide Semiconductor
MOS TECHNOLOGY
• Good for digital electronics
NMOS TECHNOLOGY
(1970s)
Complementary MOS
CMOS TECHNOLOGY
(1980s onwards)
• MOSFET IC surpassed
bipolar
• LCD replaced LED
• CMOS replaced NMOS
• Still dominates IC market
•Low power consumption
• High temperature stability
•High noise immunity
CMOS
• Ion implantation replaced diffusion
• What is Transistor and how it works?
Fab
rica
tio
nP
roc
e
ss
MOORE’S LAW
"The number of transistors incorporated in a chip will
approximately double every 24 months."
Gordon Moore, INTEL co-founder
§ Founder :
§ Gordon Moore.
§ Moore's law :
§ Rules of thumb in the history of computing
hardware.
§ The number of transistors that can be placed
on an integrated circuit DOUBLES
approximately every two years.
§ As of 2012, the highest transistor count in a
commercially available CPU is over 2.5
billion transistors, in Intel's 10- core Xeon
Westmere-EX.
IC INTEGRATION SCALE
• Small, medium and large scale
integration (SSI, MSI, LSI).
• Tens, hundreds,
thousands of transistors
on a single IC.
• Very large or ultra scale
integration (VLSI or ULSI).
• Up to a million transistor
on an IC.
• Gigascale integration (GSI) and
Terascale integration (TSI).
• Many billions and trillions
of transistor integrated on
a single semiconductor
chip.
EVOLUTION OF IC INTEGRATION SCALE
FABRICATION OF SILICON WAFER:
FROM SAND TO SILICON
Fabrication & Manufacturing Process
Design
Mask
Wafer
Fabrication
Front End
Processes
Deposition:
-Oxidation
-Diffusion
-Photolithograph
y
-Etch (wet/dry)
-Implantation
Test
Back End
Processes
Deposition
(oxide/nitride):
-Metallization
-Rapid Thermal
Process
-Lithography
-Etch (wet/dry)
Packaging
Parametric
&
Functional
Final Test
Failure
Analysis &
Reliability
BASIC OF IC FABRICATION PROCESS
• Basic of fabrication process :
• Lithography :
• The process for pattern definition by applying thin uniform layer of
viscous liquid (photo-resist) on the wafer surface. The photo-resist is
hardened by baking and than selectively removed by projection of light
through a reticle containing mask information.
• Etching :
• Selectively removing unwanted material from the surface of the wafer.
The pattern of the photo-resist is transferred to the wafer by means of
etching agents.
• Deposition :
• Films of the various materials are applied on the wafer. For this purpose
mostly two kind of processes are used, physical vapor deposition (PVD)
and chemical vapor deposition (CVD).
BASIC OF IC FABRICATION PROCESS
• Chemical Mechanical Polishing :
• is a process of smoothing surfaces with the combination of chemical and mechanical
forces.
• It can be thought of as a hybrid of chemical etching and free abrasive polishing.
• Oxidation :
• In the oxidation process oxygen (dry oxidation) or H2O (wet oxidation) molecules
convert silicon layers on top of the wafer to silicon dioxide.
• Ion Implantation :
• Most widely used technique to introduce dopant impurities into semiconductor. The
ionized particles are accelerated through an electrical field and targeted at the
semiconductor wafer.
• Diffusion :
• A diffusion step following ion implantation is used to anneal bombardment-induced
lattice defects.
FABRICATION TECHNOLOGY
§ Assembly process / IC Packaging process :
Summary
1.
2.
3.
4.
Semiconductor Material, eg: Silicon
Types of semiconductor (intrinsic-pure/extrinsic-dopant)
How’s silicon wafer made ?
How the the electron flow in the device?, refer on the basic building
block of device
5. How the IC fabrication process of the device has been made?
6. IC packaging process
7. Application of the device?