ECE 440
Homework XI
Fall 2008
Due: Monday, Nov. 17, 2008
1. Redraw Fig. 7-3 for an n+-p-n transistor, and explain the various components of carrier flow
and current directions.
2. Sketch the energy band diagram for an n-p-n transistor in equilibrium (all
ECE 440
Homework IV
Fall 2006
Due: Friday, September 15, 2006
17
3
13
3
1. A compensated germanium sample is doped with 1x10 /cm acceptors and 5x10 /cm
donors. (a) What is the electron and hole concentration respectively at room temperature
15
3
13
3
unde
ECE 440
Homework 11 Solution
Fall 2009
1. Illuminated Diode. A silicon p-n diode with reverse saturation current 10 -10 A is used as
photodiode. This diode is illuminated with sunlight, yielding a photocurrent of 1 mA. Find the
maximum power (Pm) which ca
ECE 440
Homework 12
Fall 2009
Due: Friday, Dec 4, 2009
1. Sketch the energy band diagram for an n-p-n transistor in equilibrium (all terminals grounded)
and also under normal active bias (emitter junction forward biased, collector junction reverse
biased)
ECE 440
1.
Homework XI
Summer 2006
(a) Find the voltage VFB required to reduce to zero the negative charge induced at the
semiconductor surface by a sheet of positive charge Qox located x below the metal. (b) In
the case of an arbitrary distribution of ch
ECE 440
Homework XV
Fall 2005
Due: Friday, December 2, 2005
+
1. An n -polysilicon-gate p-channel MOS transistor is made on an n-type Si substrate with Nd =
16
3
5x10 /cm . The SiO2 thickness is 100 in the gate region, and the effective interface charge
1
ECE 340
Homework I Due: Wednesday, January 28, 2004 (30 points total)
Spring 2004
1. How many atoms are found inside a unit cell of a simple cubic (sc), body-centered cubic (bcc), facecentered cubic (fcc), diamond structure, and zinc-blende structure crys
ECE 340
Homework VII Due: Monday, February 23, 2004
Spring 2004
1.
In soldering wires to a sample such as that shown in Fig. 3-25, it is difficult to align the Hall probes A and B precisely. If B is displaced slightly down the length of the bar from A, an
ECE 440
Homework I
Fall 2009
Due: Wednesday, September 02, 2009
Print your name and netid legibly. Show all work leading to your answer clearly and
neatly. Staple multiple pages.
1.
In this problem, we will be partly using a web-based simulations that are
ECE 340
1.
Homework XII Due: Friday, April 02, 2004
Spring 2004
For a p+-n silicon junction, Na=1017/cm3 in the p-side and Nd=1015/cm3 in the n-side. Determine the depletion capacitance per unit area of cm2 at 4 V.
Solutions: 1017 1015 kT N a N d ln 2 = 0
ECE 444
Fall 2005
Sakulsuk Unarunotai
sunarun2@uiuc.edu
ECE 440 Review Problems
5.9
18
3
15
3
An abrupt Si p-n junction has N a = 10 cm on one side and N d = 5 10 cm on
the other side
(a) Calculate the Fermi level positions at 300 K in the p and n regions
ECE 340
Homework IV
Fall 2005
Due: Friday, September 16, 2005
17
3
13
3
1. A compensated germanium sample is doped with 1x10 /cm acceptors and 5x10 /cm
donors. (a) What is the electron and hole concentration respectively at room temperature
15
3
13
3
unde
ECE 340
Homework V
Spring 2004
Due: Friday, February 13, 2004 (30 points total) 16 3 1. (a) Construct a semi-logarithmic plot such as Fig. 4-7 for Si doped with 4x10 /cm donors and having 14 3 4x10 EHP/cm created uniformly at t = 0. Assume that n= p = 2 s
ECE 440
Homework VI Due: Friday, October 16, 2009
Fall 2009
Please write your name and net ID on your homework. For full credit please show all work leading to your answer. Note some of the metal work functions given below may differ slightly from the tex
ECE 440
Homework VIII
Fall 2009
Due: Monday, November 02, 2009
Print your name and netid legibly. Show all work leading to your answer clearly
and neatly. Staple multiple pages.
Problem # 1: A semi-infinite p-type bar is illuminated with light which gener
ECE 440
Homework IX
Fall 2008
Due: Monday, November 03, 2008
17
3
1. A p+-n silicon diode (V o = 0.956 volts) has a donor doping of 10 /cm and an nregion width = 1 m. Does it break down by avalanche or punchthrough? What if
16
3
the doping is only 10 /cm
ECE 340
1.
Homework IX Due: Friday, March 19, 2004
Spring 2004
A n+-p Si junction with a long p-region has the following properties: Na =1.5x1016/cm3; n = 1020 cm2/V-s; p = 380 cm2/V-s; n =1 s. If we apply 0.7 V forward bias to the junction at 300 K, what
ECE 340
Homework XIII Due: Wednesday, April 07, 2004
Spring 2004
1. Redraw Fig. 7-3 for an n+-p-n transistor, and explain the various components of carrier flow and current directions.
2. Sketch the energy band diagram for an n-p-n transistor in equilibri
ECE 340
1.
Homework X Due: Monday, March 15, 2004
Spring 2004
When a prolonged diffusion or a high-energy implantation is conducted to form a p/n junction. The doping profile near the junction is usually graded, and the step-junction approach is no longer
ECE 440
HW Assignment 1 Solutions
Spring 2011
ECE 440 Homework Assignment 1 - Solutions
Due: Friday February 4th, 2011
1. In this problem, we will be using web-based simulations that are contained within the NanoHUB
website (a NSF sponsored education and
ECE 440
Homework V
Fall 2009
Due: Friday, October 09, 2009
Please write your name and net ID on your homework. Show all work leading to your
answer.
1. The acceptor profile of a silicon sample is shown below. Assume that the majority carrier
mobility can
ECE 440
Homework III
Fall 2009
Due: Friday, September 18, 2009
Print your name and netid legibly. Show all work leading to your answer clearly and
neatly. Staple multiple pages.
1. a) Construct a semi-logarithmic plot for the following experimental result
ECE 440
Homework III Solutions
Spring 2008
1. (a) It was mentioned in Section 3.2 that the covalent bonding model gives false
impression of the localization of carriers. As an illustration, calculate the radius of the
electron orbit around the donor in Fi
In answering the following multiple choice questions select and circle the most nearly correct
answers.
1. (5 points) Consider silicon doped with 1017 cm-3 donors which are all ionized. Knowing that
the electron concentration is always much greater than t
ECE 440
Homework IV
Fall 2009
Due: Friday, September 25, 2009
Print your name and netid legibly. Show all work leading to your answer clearly
and neatly. Staple multiple pages.
1. A Si bar is 0.2 cm long and 200 m2 in cross-sectional area. Find the curren
You must provide your name on the answer sheet. In addition, you are asked to voluntarily provide your social
security number in order to verify your identity and avoid confusion between two students" with the same name.
Your social security number is sou
ECE 440
Homework III
Fall 2008
Due: Monday, September 15, 2008
1. (a) A GaAs semiconductor crystal is doped with carbon atoms. If the carbon atoms displace
arsenic atoms, does the crystal become an n-type or p-type material? Why?
(b) For a nonstoichiometr
ECE 440
Homework VI
Fall 2008
Due: Wednesday, October 08, 2008
1. Consider a silicon sample at 300 K. Assume that the electron concentration varies linearly
with distance. At x=0, the electron concentration is n(0). At x=10 m, the electron
concentration i
ECE 440
Homework VI
Fall 2008
Due: Wednesday, October 08, 2008
1. Consider a silicon sample at 300 K. Assume that the electron concentration varies linearly
with distance. At x=0, the electron concentration is n(0). At x=10 m, the electron
concentration i