ECE 440
Homework XV
Fall 2004
Due: Monday, November 29, 2004
+
1. An n -polysilicon-gate p-channel MOS transistor is made on an n-type Si substrate with Nd =
16
3
6x10 /cm . The SiO2 thickness is 100 in the gate region, and the effective interface charge
Suneil Hosmane
ECE 440 Spring 05
HW 2
(1) (a) A GaAs semiconductor crystal is doped with silicon atoms. If all silicon atoms
displace Ga atoms, does the crystal become an n-type or p-type material? Why?
What if 3/4 silicon atoms displace Ga atoms while 1/
Suneil Hosmane
ECE 440 Spring 05
HW 11
1. For a p-n silicon junction, Na=1017/cm3 in the p-side and Nd=1015/cm3 in the nside. Determine the depletion capacitance per unit area of cm2 at 4 V.
We have already solved a similar problem in the previous homewor
ECE 440
Homework VI
Spring 2009
Due on Wednesday, March 04, 2009
1. Consider a silicon sample at 300 K. Assume that the difference of hole concentration varies
linearly with distance. At x=0, the hole concentration is p(0). At x=10 m, the hole
concentrati
Suneil Hosmane
ECE 440 Spring 05
HW 5
1. (a) A Si bar 0.1 cm long and 100 m2 in cross-sectional area is doped with
5x1016/cm3 arsenic atoms. Find the current at 300 K with 10 V applied across
the length.
(b) Repeat for a similar Si bar 1 m long.
(c) Back
Suneil Hosmane
ECE 440 Spring 05
HW 15
1. Aluminum and polysilicon are commonly used as gate metals for the MOS structure
in silicon. Assume that platinum is used as the gate metal. Reconstruct a diagram
similar to Figure 6-17 showing the variation of the
ECE 440
Homework II
Spring 2009
Due on Wednesday, February 04, 2009
1. (a) A GaAs semiconductor crystal is doped with silicon atoms. If all silicon atoms displace
Ga atoms, does the crystal become an n-type or p-type material? Why? What if 3/4 silicon
ato
ECE 440
Homework XVI
Fall 2004
Due: Friday, December 03, 2004
1. A lightly-doped-drain (LDD) structure is incorporated in a MOSFET. To fabricate
such a structure, a heavy diffusion or implantation is first used to increase the doping in
the drain region.
ECE 440
Homework XVII
Fall 2004
Due: Wednesday, December 08, 2004
1. Refer to Fig. 1-13. Assuming the lattice constant varies linearly with composition x for a
ternary alloy, what composition of GaSb1-xAsx is lattice-matched to InP? What composition
of In
1
Spring 2009
ELECTRICAL AND COMPUTER ENGINEERING 440
Solid State Electronic Devices
The course director is Prof. K.C. Hsieh
The course structure consists of three lecture/discussion meetings per week.
Final course grades are based on the distribution of
ECE 440
Homework I
Spring 2009
Due on Wednesday, January 28, 2009
1. How many atoms are found inside a unit cell of a simple cubic (sc), body-centered cubic
(bcc), face-centered cubic (fcc), diamond structure, and zinc-blende structure crystal? Find
the m
ECE 440
11.
Homework I Solutions
Spring 2009
How many atoms are found inside a unit cell of a simple cubic (sc), body-centered cubic
(bcc), face-centered cubic (fcc), diamond structure, and zinc-blende structure crystal? Find
the maximum fractions of the
ECE 440
Homework II
Spring 2009
Due on Wednesday, February 04, 2009
1. (a) A GaAs semiconductor crystal is doped with silicon atoms. If all silicon atoms displace
Ga atoms, does the crystal become an n-type or p-type material? Why? What if 3/4 silicon
ato
ECE 440
Homework XIV
Fall 2004
Due: WednesdaY, November 17, 2004
1. Other than aluminum, polysilicon is another common gate metal for the MOS structure in
silicon. By incorporating heavy doping during chemical vapor deposition of polysilicon one
can great
ECE 440
Homework XIII
Fall 2004
Due: Friday, November 12, 2004
1. Field-effect transistors employ a mechanism different from that of BJT to control the output
current by changing the charge density in the active region. The following problem is
designed t
ECE 440
Homework XII
Fall 2004
Due: Monday, November 01, 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 equilibrium
ECE 440
Homework XI
Fall 2004
Due: Wednesday, October 27, 2004
1. A Schottky barrier is formed between a metal having a work function of 4.2 eV and p-type Si
(electron affinity = 4 eV). The acceptor doping in the Si is 5x1017/cm3. (a) Draw the equilibrium
ECE 440
Homework X
Fall 2004
Due: Friday, October 22, 2004
+
1. A p -n silicon diode (Vo = 0.956 volts) has a donor doping of 1017/cm3 and an nregion width = 1 m. Does it break down by avalanche or punchthrough? What if the
16
3
doping is only 10 /cm ? Re
ECE 440
Homework IX
Fall 2004
Due: Monday, October 18, 2004
1. An abrupt Si p-n junction has the following properties at 300 K:
p-side
-3
n-side
17
3
Na = 2x10 /cm
n = 0.1 s
2
p = 190 cm /V-s
2
n = 600 cm /V-s
2
A = 10 cm
15
3
Na = 4x10 /cm
p = 10 s
2
ECE 440
Homework VIII
Fall 2004
Due: Monday, October 11, 2004
16
3
17
3
1. An abrupt Si p-n junction has Na = 7x10 /cm on the p-side and Nd = 2x10 /cm on the nside.
(a) Calculate the Fermi level positions at 300 K in the p and n regions.
(b) Draw an equil
ECE 340
Homework VII
Fall 2004
Due: Friday, October 01, 2004
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 is
ECE 440
Homework III
Spring 2009
Due on Wednesday, February 11, 2009
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 or
ECE 440
Homework III
Spring 2009
Due on Wednesday, February 11, 2009
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 or
ECE 440
Homework IV
Spring 2009
Due on Wednesday, February 18, 2009
1.
A silicon sample is doped with 2x10 14 As atoms/cm3. (a) What are the electron and hole
concentrations, respectively, at 500 K under equilibrium conditions? (b) Where is E F positioned
ECE 440
Homework XI
Spring 2009
Due on Wednesday, April 22, 2009
1.
2.
Assume that a p-n-p transistor is doped such that the emitter doping is 10 times that in the
base, the minority carrier mobility in the emitter is one-half that in the base, and the ba
ECE 440
Homework X
Spring 2009
Due on Wednesday April 15, 2009
1. Assume that a p+ -n diode with a uniform cross section area, A, is built with an n
region width l smaller than a hole diffusion length ( l < Lp). This is the so-called
narrow base diode. Si
ECE 440
Homework X
Spring 2009
Due on Wednesday April 15, 2009
1. Assume that a p+ -n diode with a uniform cross section area, A, is built with an n
region width l smaller than a hole diffusion length ( l < Lp). This is the so-called
narrow base diode. Si
ECE 440
Homework X
Spring 2009
Due on Wednesday April 15, 2009
1. Assume that a p+ -n diode with a uniform cross section area, A, is built with an n
region width l smaller than a hole diffusion length ( l < Lp). This is the so-called
narrow base diode. Si
sherECE 440
Homework IX
Spring 2009
Due on Wednesday April 08, 2009
1. A newly fabricated silicon p-n junction in the ECE440 lab is to be characterized under
forward biasing. The uncompensated doping concentrations in the p and n side are
NA=4x1017/cm3 an