반도체공학
(Semiconductor Physics and Devices)
E-mail: [email protected] Phone: 051-510-2381
Office hour: Mon. Wed. 15:00 ~ 17:00
Evaluation: Attitude(~5%) + Mid(~40%) + Final(~45%) + Report(~10%)
Chapter 1: The Crystal Structure of Solids
Chapter 2: Introduction to Quantum Mechanics
Chapter 3: Introduction to the Quantum Theory of Solids Chapter 4: Semiconductor in Equilibrium
Chapter 5: Carrier Transport Phenomena
Chapter6: Nonequilibrium Excess Carriers in Semiconductors Chapter7: The pn Junction
Chapter8: The pn Junction Diodes
Chapter9: Metal-Semiconductor and Semiconductor Heterojunctions Chapter10: Fundamentals of the Metal-Oxide-Semiconductor FET Chapter11: Metal-Oxide-Semiconductor FET Additional Concepts Chapter12: The Bipolar Transistor
Chapter 1
The Crystal Structure of Solids
1.1 Semiconductor Materials 1.2 Types of Solids
1.3 Space Lattices
1.4 The Diamond Structure 1.5 Atomic Bonding
1.6 Imperfections and Impurities in Solids 1.7 Growth of Semiconductor Materials
1.1 Semiconductor Materials
Elemental : Silicon or Germanium
Compound : binary, ternary,
1.2 Types of Solids : depending on the size of ordered region within material
(a) Amorphous: Ordered in a few atomic or molecular dimension
(b) Polycrystalline: Grain and Grain boundary
(c) Single Crystal: Superior electrical properties
1.3 Space Lattices
Lattice : The periodic arrangement of atoms in the crystal
Unit cell : A small volume of the crystal that can be used to reproduce the entire crystal
A generalized primitive unit cell in 3-D Basic Crystal Structures
(a) SC : simple cubic
(b) BCC : body-centered cubic (c) FCC : face-centered cubic
Different Volume density of atoms !!
Face centered cubic Simple cubic Body centered
cubic
Simple tetragonal
Body centered tetragonal
Simple orthorhombic
Body centered orthorhombic
Base centered orthorhombic
Face centered orthorhombic
Rhombohedral Hexagonal
RHOMBOHEDRAL SYSTEM a=b=c α=β=γ ≠90°
Arsenic, Boron, Bismuth, Antimony, Mercury (<-39°C)
Simple monoclinic
Base centered monoclinic
Triclinic
TRICLINIC SYSTEM a≠b≠c α ≠ β ≠ γ ≠90°
Potassium dicromate
UNIT CELL GEOMETRY
The seven crystal systems (unit cell geometries) and fourteen Bravais lattices.
CUBIC SYSTEM a=b=c α=β=γ=90°
Many metals, Al, Cu, Fe, Pb. Many ceramics and semiconductors, NaCl, CsCl, LiF, Si, GaAs TETRAGONAL SYSTEM
a=b≠c α=β=γ= 90°
In, Sn, Barium Titanate, TiO2
ORTHORHOMBIC SYSTEM a≠b≠c α=β=γ= 90°
S, U, Pl, Ga (<30°C), Iodine, Cementite (Fe3C), Sodium Sulfate
HEXAGONAL SYSTEM a=b≠c α=β= 90°;γ= 120°
Cadmium, Magnesium, Zinc, Graphite
MONOCLINIC SYSTEM a≠b≠c α=β=90° ;γ≠ 90°
α−Selenium, Phosphorus Lithium Sulfate
Tin Fluoride
1.3 Space Lattices
Crystal Planes and Miller Indices
1.3 Space Lattices
(100)
(001) (110)
(111)
-z
y x
z
x
(110)
z
-y y
(111)
y z
(010) (010) (010) (010)
x
(010)
x z
y
(b) Various planes in the cubic lattice
Miller Indices (hkl ) :
1 1 1
∞1 (210) 1
2
zintercept at∞
a b
c
x
y xintercept ata/2
yintercept atb
Unitcell
z
(a) Identification of a plane in a crystal
0 0 0
0 0 0
Intercepts , , and are 3 , 2 , and 1
1 1 1
Reciprocals , , and are
1 1 1
, , and (2, 3, 6)
3 2 1
x y z a b c
x y z
=
( ) ( ) ( )
( ) ( ) ( ) { }
100 , 010 , 001 , 100 , 010 , 001 100
⇒
Family of Planes
The distance between nearest equivalent parallel planes
The surface concentration of atoms
1.3 Space Lattices
z
y = −a y
12 z= a
( )
012x a
FCC Unit Cell
0 0 0
0 0 0
Intercepts , , and are , 1 , and 1 2
1 1 1
Reciprocals , , and are
1 1 1
, , and 0,1, 2 1 1
2
x y z a a
x y z
∞ −
∞ − = Examples
Directions
1.3 Space Lattices
“Many properties, for example, the elastic modulus, electrical resistivity, magnetic susceptibility, etc., are directional within the crystal.”
[ ] [ ] [ ]
100 , 010 , 001 , 100 , 010 , 001 100 ⇒
[010]
[100]
[001]
[010]
[110]
[111]
[110]
-y -a x a
y
[111]
[111]
[111]
[111]
[111]
[111]
[111] Family of <111> directions
(c) Directions in cubic crystal system
Family of directions
(a) (100) plane and [100] direction (b) (110) plane and [110] direction (c) (111) plane and [111] direction
1.4 The Diamond Structure
Diamond structure • Covalently bonded solids; Si, Ge, diamond, etc.
• Eight atoms in the unit cell.
Zincblende structure
1.5 Atomic bonding
H 109.5°
C
H H
H
(c) H
H H
H
Lshell Kshell
Covalent bond
C
(a)
C H
H H
H
covalent bonds
(b)
Free valence electrons forming an
electron gas Positive metal
ion cores
3s 3p
ClosedKandLshells 3s
ClosedKandLshells (a)
3s3p FA
r
FA
ro (c)
Na Cl
Na+
Cl-
Na+
Cl-
A B
A B′
(b)
H Cl
(a)
Covalent bond
Vander Waals force Ionic bond
Metallic bond
1.6 Imperfections and impurities in solids
Point defects
(a) A vacancy in the crystal. (b) A substitutional impurity in the crystal. The impurity atom is larger than the host atom.
(c) A substitutional impurity in the crystal. The impurity atom is smaller than the host atom.
(d) An interstitial impurity in the crystal. It occupies an empty space between host atoms.
Line defects and Planar Defects
Dislocation line Grain
Grain boundary Vacancy
Interstitial Substitutional Doping
1.7 Growth of Semiconductor Materials
Schematic illustration of the growth of a single-crystal Si ingot by the Czochralski technique.
Electronic grade silicon : 99.99999999999 % pure.
Zone refining (Segregation coefficient)
Controlled amounts of specific impurity atoms can be added
Flat zone
Sawing, cutting and polishing
Epitaxial Growth : A thin single-crystal layer growth on the surface of a single- crystal substrate
Homoepitaxy
Heteroepitaxy
Homework
- Review Questions - 1.5
- 1.13 - 1.15 - 1.21
-Due day : Before the beginning of class after a week from today
