ECE 340
Homework Assignment #1
Spring 2016
D UE : F RIDAY, J ANUARY 29, 2016
P RINT YOUR NAME AND N ET ID LEGIBLY. F OLLOW THE GUIDELINES AND FORMAT GIVEN IN THE SYLLABUS .
S TAPLE MULTIPLE PAGES . S HOW ALL UNITS . H OMEWORK MUST BE TURNED IN AT THE BEGI
ECE 340
Lecture 11 : Effects of
Temperature and High Field
on Mobility
Class Outline:
Drift and Resistance
Temperature and Mobility
High Field Effects
Band Bending
Things you should know when you leave
Key Questions
What is the resistivity?
How does tem
Homework Assignment #4
ECE 340
Fall2012
Due: Friday, September 28th, 2012
Print your name and NetID legibly. Follow the guidelines and format given in the syllabus. Staple multiple
pages. Put all units.
1. (a) An average hole drift velocity of 104 cm / se
ECE 340
Homework Assignment #1
Fall2012
1. A convenient unit of length for description of solids is the nanometer (nm), which is the order of magnitude of a typical distance between atoms. (Actual sizes are between 0.1 nm and 1.0 nm. Many older texts use
ECE 340
Lecture 24 : Quantitative
Current Flow in a P-N
Junction
Class Outline:
Quantitative PN Junction Current
Things you should know when you leave
Key Questions
How do we calculate excess
carriers under bias?
How do we calculate the total
current?
Homework Solutions #8
ECE 340
Spring 2016
D UE : F RIDAY,A PRIL 1, 2016
Print your name and NetID legibly. Follow the guidelines and format given in the syllabus. Staple multiple pages.
Show all units. Homework must be turned in at the beginning of class
9/11/12
Things you should know when you leave
Key Questions
ECE 340
Lecture 7 : Fermi Level and
Equilibrium Carrier
Distributions
What is the density of states?
What does the Fermi function tell
us?
What is the Fermi level?
How do I find the equilib
ECE 340
Lecture 9 : Carrier
Concentrations and the
Temperature Dependence
Class Outline:
Intrinsic Carrier Concentrations
Extrinsic Carrier Concentrations
Thermal Effects Revisited
Things you should know when you leave
Key Questions
What is the charge n
ECE 340
Lecture 10 : Drift of Carriers
in Electric Fields
Class Outline:
Conductivity and Mobility
Things you should know when you leave
Key Questions
How do carriers move through a
semiconductor?
How does applying an electric
field change the motion?
ECE 340
Lecture 13 : Optical
Absorption and Luminescence
Class Outline:
Band Bending
Optical Absorption
Things you should know when you leave
Key Questions
How do I calculate kinetic and
potential energy from the
bands?
What is direct recombination?
Ho
ECE 340
1.
Homework Solution #9
Spring 2016
L IGHT EMITTING DIODES
(A). Group-IV and III-V semiconductors have a specific energy gap and can emit a certain wavelength. However, their natural emission wavelengths are not always practically useful. In most
ECE 340
Lecture 14 : Carrier R-G I
Class Outline:
Direct Recombination
Steady State Carrier Generation
Things you should know when you leave
Key Questions
What are the major mechanisms
for recombination?
What are the major mechanisms
for generation?
Wh
ECE 340
1.
Homework Solution #7
Spring 2016
QUALITATIVE D IODE C URRENTS
( A ). Since the positive terminal of the voltage source is connected to the p-side of the diode, the sample is
under forward bias.
Diffusion is a majority carrier process and depend
ECE 340
Homework Solution #10
Spring 2016
D UE : F RIDAY, A PR . 22, 2016
P RINT YOUR NAME AND N ET ID LEGIBLY. F OLLOW THE GUIDELINES AND FORMAT GIVEN IN THE SYLLABUS .
S TAPLE MULTIPLE PAGES . S HOW ALL UNITS . H OMEWORK MUST BE TURNED IN AT THE BEGINNI
ECE 340
1.
Homework Solution #6
Spring 2016
D RIFT AND DIFFUSION
(A). To find the hole mobility, we first need to find the electric field in the sample.
E=
V
7V
=
= 14 V/cm
L 0.5 cm
(1.1)
Then, the hole velocity can be written in terms of the mobility as
ECE 340
1.
Homework Solution #11
Spring 2016
BJT IN EQUILIBRIUM
21018
(A). Emitter (n-type): F n E i = 0.0259 ln 1.510
10 ' 0.485 eV.
21016
Base (p-type): E i F p = 0.0259 ln 1.510
10 ' 0.365 eV.
51015
Collector (n-type): F n E i = 0.0259 ln 1.510
10 ' 0.
9/10/12
Things you should know when you leave
Key Questions
ECE 340
Lecture 6 : Intrinsic and
Extrinsic Material I
What is the physical meaning of
the effective mass
What does a negative effective
mass mean?
What is intrinsic material?
What is therm
9/6/12
Things you should know when you leave
ECE 340
Lecture 5 : Energy Bands and
Charge Carriers
Class Outline:
Metals, Semiconductors, and Insulators
Electrons and Holes
Key Questions
How can we use the band gap to
classify materials?
What is the di
9/4/12
Things you should know when you leave
Key Questions
ECE 340
Lecture 4 : Bonding Forces
and Energy Bands
Why is the Bohr model useful?
What is the Schrdinger equation?
What is a wavefunction?
What are the most common
chemical bonds?
What are
Problem # 1:
=
Plot and label the C-V curve o f a PMOS capacitor with p+ gate, substrate doping o f ND= 5x10 17
NA
3
cm- and S i0 2 = 2 nm.
- ,
C
0 ')( - :.
e
tP")(
do
=
3/~)(
. s.8S
2lrC
>"
%,., =
D
' b 7 c.\"\"\
-"
\.1~)or' ()
FI
I C tfY\
~'.~.
'f~ ~O'J
Problem # 1:
(a) Show that the minimum conductivity of a semiconductor sample occurs when n0 = ni
(p/n).
(b) What is the expression for the minimum conductivity?
(c) Calculate the minimum conductivity for Si
Problem #1:
Consider the p-i-n structure shown above. Assume that the p and n regions are
uniformly doped and that ND - NA = 0 in the intrinsic region. Please answer the following:
a. Plot the charge, electric field, and potential within the device struct
. .
Problem #1:
~
P
I
~
- x'/2
I
.
'
n
.
x I'/2
Consider the p-i-n structure shown above. Assume that the p and n regions are
uniformly doped and that ND - NA = 0 in the intrinsic region. Please answer the following:
a. Plot the charge, electric field, a
ECE 340
Homework 5
Due: Feb 24, 2012
For all problems, assume T = 300 K if not stated otherwise.
1. Construct a semilogarithmic plot such as Fig. 4-7 (S&B) for GaAs doped with 6 1015donors/cm3and having
3 1014 EHP/cm3 created uniformly at t=0. Assume that
14
3 10 EHP/cm
3
n = p = 20ns.
6 1015
1 1013 /cm3 ?
no = 6 1015 /cm3
4p = 4n = 3 1014 /cm3
p(t) p = 4pe
=
n(t) = 4ne
t / n
t/p
+ no
1 1013 /cm3
r
gop
r
= 1020 EHP/cm3
s.
n=
p.
3
r =
1
no
=
1
(2010
gop = r (no n
n2 + (6 1015 ) n
9 )(61015 )
n2 ) = 8.33 10
ECE 340
Homework 6
1. An n-type silicon sample doped with
15
3
p = 5 10 /cm
Due: Mar 12, 2012
ND = 1017 /cm3
is in steady state with an excess hole concentration
injected at x = 0. Assume the sample cross-sectional area is
5 1016 cm2 .
(a) Determine the m
ECE 340
Summer2012
Homework 1 Solution
1. Solve part (a) and (b) in terms of the lattice constant a
a) What is the distance between nearest-neighbor atoms in a diamond
structure (e.g. Silicon)
Diamond/Zincblende:
The diamond lattice is almost i
ECE 340
Homework Assignment #11
Fall 2016
D UE : F RIDAY, D ECEMBER 2, 2016
P RINT YOUR NAME AND N ET ID LEGIBLY. F OLLOW THE GUIDELINES AND FORMAT GIVEN IN THE SYLLABUS .
S TAPLE MULTIPLE PAGES . S HOW ALL UNITS . H OMEWORK MUST BE TURNED IN AT THE BEGIN