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ECE 440  Solid State Electronic Devices  University Of Illinois, Urbana Champaign Study Resources

Ece340Spring04HW1Sol
School: University Of Illinois, Urbana Champaign
Course: Ece440
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), bodycentered cubic (bcc), facecentered cubic (fcc), diamond structure, and zincblende structure crys

Hw4
School: University Of Illinois, Urbana Champaign
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

Ece340Spring04hw7sol
School: University Of Illinois, Urbana Champaign
Course: Ece440
ECE 340 Homework VII Due: Monday, February 23, 2004 Spring 2004 1. In soldering wires to a sample such as that shown in Fig. 325, 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

Hw6
School: University Of Illinois, Urbana Champaign
Course: Ece440
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

Ece340Spring04HW11Sol
School: University Of Illinois, Urbana Champaign
Course: Ece440
ECE 340 1. Homework IX Due: Friday, March 19, 2004 Spring 2004 A n+p Si junction with a long pregion has the following properties: Na =1.5x1016/cm3; n = 1020 cm2/Vs; p = 380 cm2/Vs; n =1 s. If we apply 0.7 V forward bias to the junction at 300 K, what

Ece340Spring04hw13Sol
School: University Of Illinois, Urbana Champaign
Course: Ece440
ECE 340 Homework XIII Due: Wednesday, April 07, 2004 Spring 2004 1. Redraw Fig. 73 for an n+pn transistor, and explain the various components of carrier flow and current directions. 2. Sketch the energy band diagram for an npn transistor in equilibri

Ece340Spring04HW10Sol
School: University Of Illinois, Urbana Champaign
Course: Ece440
ECE 340 1. Homework X Due: Monday, March 15, 2004 Spring 2004 When a prolonged diffusion or a highenergy implantation is conducted to form a p/n junction. The doping profile near the junction is usually graded, and the stepjunction approach is no longer

Hw14
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XIV Fall 2006 Due: Wednesday, November 15, 2006 1. For an ideal MOS structure, the SiO2 thickness is 200 , and the substrate is doped with 16 3 10 /cm acceptors. Determine the threshold voltage, VT, required to achieve strong inversion an

Hw13
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XIII Fall 2006 Due: Friday, November 10, 2006 1. Fieldeffect 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

Hw12
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XII Fall 2006 Due: Wednesday, Nov 01, 2006 + 1. Redraw Fig. 73 for an n pn transistor, and explain the various components of carrier flow and current directions. 2. Sketch the energy band diagram for an npn transistor in equilibrium

Hw11
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XI Fall 2006 Due: Wednesday, October 25, 2006 1. A Schottky barrier is formed between a metal having a work function of 4.2 eV and ptype Si (electron affinity = 4 eV). The acceptor doping in the Si is 6x1017/cm3. (a) Draw the equilibrium

Hw10
School: University Of Illinois, Urbana Champaign
ECE 440 Homework X Fall 2006 Due: Friday, October 20, 2006 + 17 3 1. A p n silicon diode (Vo = 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 the 16 3 doping is only 10 /cm ?

Hw3_solutions
School: University Of Illinois, Urbana Champaign
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

Hw9
School: University Of Illinois, Urbana Champaign
ECE 440 Homework IX Fall 2006 Due: Monday, October 16, 2006 1. An abrupt Si pn junction has the following properties at 300 K: pside 3 nside 17 Na = 3x10 /cm 3 n = 0.1 s A = 10 cm 15 Na = 6x10 /cm 2 3 p = 10 s 2 n = 1160 cm /Vs 2 p = 420 cm /Vs p

Hw7
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VII Fall 2006 Due: Friday, September 29, 2006 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

Hw6
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VI Fall 2006 Due: Monday, September 25, 2006 17 3 1. (a) Construct a semilogarithmic plot such as Fig. 47 for GaAs doped with 1x10 /cm 15 3 acceptors and having 2x10 EHP/cm created uniformly at t = 0. Assume that n= p =50 ns. (b) Calcula

Hw6_solutions
School: University Of Illinois, Urbana Champaign
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

Hw5
School: University Of Illinois, Urbana Champaign
ECE 440 Homework V Fall 2006 Due: Friday, September 22, 2006 2 17 3 1. A Ge bar 1m long and 100 m in crosssectional area is doped with 1x10 /cm gallium. Find the current at 300 K with 10 V applied assuming that the saturation thermal velocity of 7 electr

Hw3
School: University Of Illinois, Urbana Champaign
ECE 340 Homework III Fall 2006 Due: Monday, September 11, 2006 1. In practice we assume that the intrinsic Fermi level, Ei, coincides with the center of the band gap. In reality it is not true. Derive an expression relating the intrinsic level Ei to the c

Hw15
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XV Fall 2006 Due: Wednesday, November 29, 2006 + 1. An n polysilicongate pchannel MOS transistor is made on an ntype Si substrate with Nd = 16 3 5x10 /cm . The SiO2 thickness is 100 in the gate region, and the effective interface char

Hw16
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XVI Fall 2006 Due: Monday, December 04, 2006 1. A lightlydopeddrain (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.

Exam1_solutions
School: University Of Illinois, Urbana Champaign

Exam2_solutions
School: University Of Illinois, Urbana Champaign

ECE 440 Review Problems
School: University Of Illinois, Urbana Champaign
ECE 444 Fall 2005 Sakulsuk Unarunotai sunarun2@uiuc.edu ECE 440 Review Problems 5.9 18 3 15 3 An abrupt Si pn 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

Final_exam_example_sp03
School: University Of Illinois, Urbana Champaign
In answering the following multiple choice questions select and circle the most nearly correct answers. 1. (5 points) Consider silicon doped with 1017 cm3 donors which are all ionized. Knowing that the electron concentration is always much greater than t

ECE%20440%20Review%20Problems
School: University Of Illinois, Urbana Champaign
ECE 444 Fall 2005 Sakulsuk Unarunotai sunarun2@uiuc.edu ECE 440 Review Problems 5.9 An abrupt Si pn junction has N a = 1018 cm 3 on one side and N d = 5 1015 cm 3 on the other side (a) Calculate the Fermi level positions at 300 K in the p and n regions.

ECE 440 Review Problems
School: University Of Illinois, Urbana Champaign
x e 0.002 0 0.455 0 3.48 0 2 1 0 0.1 0 0.1 0.2 0.3 0.4 0.5 1 2 3 4 0.1 0 0.02 0 0.02 1.00E+18 0 1.00E+18 0 2.00E+16 0.455 2.00E+16 0.455 0.00E+00 0.5 0.00E+00 200000000000000000 0 0.1 0 200000000000000000 0.1 0.2 0.3 5x10 400000000000000000

Hw4_sol_09
School: University Of Illinois, Urbana Champaign
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 crosssectional area. Find the curren

Hw3_solution
School: University Of Illinois, Urbana Champaign
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 ntype or ptype material? Why? (b) For a nonstoichiometr

HW3_sol
School: University Of Illinois, Urbana Champaign
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 semilogarithmic plot for the following experimental result

Hw5_solution_fall09
School: University Of Illinois, Urbana Champaign
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

Hw17
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XVII Fall 2006 Due: Friday, December 8, 2006 1. Refer to Fig. 113. Assuming the lattice constant varies linearly with composition x for a ternary alloy, what composition of GaSb1xAsx is latticematched to InP? What composition of InxGa1

Hw4
School: University Of Illinois, Urbana Champaign
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

Hw2
School: University Of Illinois, Urbana Champaign
ECE 440 Homework II Fall 2006 Due: Wednesday, September 06, 2006 1. (a) A GaAs semiconductor crystal is doped with carbon atoms. If the carbon atoms displace arsenic atoms, does the crystal become an ntype or ptype material? Why? (b) For a nonstoichiome

Hw1
School: University Of Illinois, Urbana Champaign
ECE 440 Homework I Fall 2006 Due: Wednesday, August 30, 2006 1. How many atoms are found inside a unit cell of a simple cubic (sc), bodycentered cubic (bcc), facecentered cubic (fcc), diamond structure, and zincblende structure crystal? Find the maximu

ECE440_1st HE_Sol Spr05
School: University Of Illinois, Urbana Champaign

ECE440_1st HE_Sol Fall07
School: University Of Illinois, Urbana Champaign

ECE440_1st HE Conflict_Sol Fall08
School: University Of Illinois, Urbana Champaign

Ex2_example2_solution
School: University Of Illinois, Urbana Champaign

Problem 3
School: University Of Illinois, Urbana Champaign
Solar Cell problem A single pn junction solar cell with the crosssectional area of 1 cm x 1 cm is placed in a completely dark environment. The top layer of the pn junction is a 15 m thick ptype silicon layer and the bottom layer is a 100 m thick ntyp

Problem 4
School: University Of Illinois, Urbana Champaign
Exam 2 Question 3 Solution (DW) a 18 3 d 15 3 An abrupt p+n junction has N =2x10 cm , N =5x10 cm and T=300K. a) (4pts) The pnjunction is reverse biased with V=5V. What are the excess hole and electron concentrations at the edges of the transition regi

Ex2_example1_solution
School: University Of Illinois, Urbana Champaign
1. The room temperature IV characteristic of a silicon np junction under reverse bias is shown below. The doping density for the Pside (NA) is 4 times that in the Nside (NA = 4ND). Relevant data is given below: Ln L p L 1 m ; Dn D p D 40 cm 2 ; n i 101

Problem 1 And 2
School: University Of Illinois, Urbana Champaign
ECE 340 Exam 2 Problem 1  2 Solution 1. The band diagram of a silicon NP+ junction at T = 300K is shown below. Assume the intrinsic level is just in the middle of the band gap Ei = Eg /2 and ECn Fn = 0.18eV (a) Calculate the dopant concentration on the

Example Final Exam
School: University Of Illinois, Urbana Champaign
1) MOS CAPACITOR (20 points) A highfrequency capacitance voltage measurement of a silicon MOS structure was fitted by the following expression, where VG is the gate voltage in units of Volts: C(VG) = 6 pF +12 pF/(1 + exp(VG) The area of the capacitor is

Quiz3
School: University Of Illinois, Urbana Champaign

Quiz1D_solution
School: University Of Illinois, Urbana Champaign

Problem 1 And 3
School: University Of Illinois, Urbana Champaign
ECE 340 February 28, 2012 First Hour Exam Name:_Section_ Useful Formulas and Data: Problem1 A semiconductor has a nonuniform doping profile that results in the band diagram shown in the figure below. At T=300K the energy gap is EG=42kBT, and the intrinsi

NarrowBaseBJT
School: University Of Illinois, Urbana Champaign
N arrowBaseD iode A n arrowbase *n d iode i s s ketched elow a long w ith t he e quilibrium b and p b diagram.D iffusion o f m inority h oles w ithin t he n regionw ill b e c haracterizedvery simply t hroughu se o f a ' straightline' a pproximation.

Problem 2
School: University Of Illinois, Urbana Champaign

Hw14_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XIV Solutions Fall 2005 Due: Wednesday, November 16, 2005 1. For an ideal MOS structure, the SiO2 thickness is 150 , and the substrate is doped with 16 3 10 /cm acceptors. Determine the threshold voltage, VT, required to achieve strong in

Hw7_solutions
School: University Of Illinois, Urbana Champaign

Hw8_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VIII Fall 2005 Due: Monday, October 10, 2005 16 3 17 3 1. An abrupt Si pn junction has Na = 7x10 /cm on the pside and Nd = 2x10 /cm on the nside. (a) Calculate the Fermi level positions at 300 K in the p and n regions. P region: 7 1016

Hw9_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework IX Solutions Fall 2005 Due: Monday, October 17, 2005 1. An abrupt Si pn junction has the following properties at 300 K: 3 nside pside 17 3 2 A = 10 cm 15 3 Na = 2x10 /cm Nd = 4x10 /cm n = 0.1 s p = 10 s 2 n = 1200 cm /Vs 2 p = 420

Hw6_solutions
School: University Of Illinois, Urbana Champaign
17  p(t) = p + p0 [cm 3] 1.02 Carrier Concentrations x 10 1.015 1.01 1.005 1 0 50 100 150 200 250 300 0 50 100 150 t [ns] 200 250 300 16  log( n(t) = n + n0 ) [cm 3] 10 15 10 14 10 13 10 12 10

Hw4_solutions
School: University Of Illinois, Urbana Champaign

Hw5_solutions
School: University Of Illinois, Urbana Champaign

ECE440fa05_HW1_sol
School: University Of Illinois, Urbana Champaign

Hw3_solutions
School: University Of Illinois, Urbana Champaign

Hw2_solutions
School: University Of Illinois, Urbana Champaign

ECE440_1st HE_Sol Spr07
School: University Of Illinois, Urbana Champaign

Quiz2
School: University Of Illinois, Urbana Champaign

Hw11_solutions
School: University Of Illinois, Urbana Champaign
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

Hw4_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework IV 10 3 Summer 2006 15 3 1. A direct semiconductor with n i = 10 /cm is doped with 10 /cm donors. Its lowlevel carrier 7 lifetime n = p = 10 sec. (a) If a sample of this material is uniformly exposed to a steady optical generation rate

Hw5
School: University Of Illinois, Urbana Champaign
ECE 440 Homework V Summer 2006 Due: Thursday, June 29, 2006 14 1. A 1cm long Ge bar has a linear acceptor distribution NA = 10 3 (1 +ax) /cm , where a = 10/mm. (a) Plot the hole carrier distribution at equilibrium at 300 K from x=0 to 1 cm. (b) Estimate

Hw3_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework III Summer 2006 1. Calculate both the electron and hole concentrations for a germanium sample doped with 16 3 1x10 arsenic atoms/cm Doping germanium with arsenic will make the sample ntype. Thus, ND = 1x1016 cm3. To find the concentrati

Hw1_solution
School: University Of Illinois, Urbana Champaign
ECE 440 Homework I Solutions Summer 2006 1. Assuming that the lattice constant varies linearly with the composition, determine the unit cell side length for a silicongermanium alloy (in diamond structure) which has an atomic 22 3 density of 4.5x10 atoms/

Hw3
School: University Of Illinois, Urbana Champaign
ECE440 HomeworkIII Summer2006 Due:Thursday,June22,2006 1. Calculateboththeelectronandholeconcentrationsforagermaniumsampledopedwith 16 3 1x10 arsenicatoms/cm (a)atroomtemperature(b)at450K. 14 3 13 3 2. Agermaniumsampleisdopedwith1x10 /cm acceptorsand6x10

Hw2_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework II Summer 2006 1. An InP semiconductor crystal is doped with tin atoms. If the tin displaces phosphorous atoms, does the crystal become an ntype or ptype material? Why? InP is a III V compound semiconductor. Tin (Sn) is a column IV elem

Hw2
School: University Of Illinois, Urbana Champaign
ECE440 HomeworkII Summer2006 Due:Tuesday,June20,2006 1. AnInPsemiconductorcrystalisdopedwithtinatoms.Ifthetindisplacesphosphorous atoms,doesthecrystalbecomeanntypeorptypematerial?Why? 2. CalculateandexplicitlyplottheFermifunctionversusenergyfromE=EF0.20eV

Hw1
School: University Of Illinois, Urbana Champaign
ECE440 HomeworkI Summer2006 Due:Thursday,June15,2006 1. Assumingthatthelatticeconstantvarieslinearlywiththecomposition,determinetheunit cellsidelengthforasilicongermaniumalloy(indiamondstructure)whichhasanatomic 22 3 densityof4.5x10 atoms/cm .Also,findthe

Hw13_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XIII Fall 2008 Due: Monday, Dec. 08, 2008 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 greatly inc

Hw13
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XIII Fall 2008 Due: Monday, Dec. 08, 2008 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 greatly inc

Hw12_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XII Fall 2008 Due: Monday, December 01, 2008 1. Fieldeffect 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 to

Hw4
School: University Of Illinois, Urbana Champaign
ECE440 HomeworkIV Summer2006 Due:Tuesday,June27,2006 10 3 15 3 1. Adirectsemiconductorwithni=10 /cm isdopedwith10 /cm donors.Itslowlevelcarrier 7 lifetimen=p=10 sec.(a)Ifasampleofthismaterialisuniformlyexposedtoasteadyoptical 22 3 generationrateofgop=2x10

Hw6
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VI Summer 2006 Due: Thursday, July 06, 2006 17 3 15 3 1. An abrupt Si pn junction has NA = 3 x 10 /cm on the pside and ND = 2x10 /cm on the nside. (a) Calculate the Fermi level positions in the p and n regions at 300 K. (b) Draw an equ

Hw10_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework X Solutions Summer 2006 1. Redraw Fig. 612 for the pchannel (ntype substrate) case. Also include schematic drawings showing the electric circuit and contact configurations. 1 15 3 2. An ideal MOS capacitor which is made on an ntype Si

Hw11
School: University Of Illinois, Urbana Champaign
ECE 440 1. Homework XI Summer 2006 Due: Tuesday, August 01, 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 a

Hw9_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework IX Due: Thursday, July 20, 2006 Summer 2006 + 1. Assume that a p n diode is built with an n region width l smaller than a hole diffusion length ( l < Lp). This is the socalled narrow base diode. Since for this case holes are injected in

Hw9
School: University Of Illinois, Urbana Champaign
ECE 440 Homework IX Due: Thursday, July 20, 2006 Summer 2006 + 1. Assume that a p n diode is built with an n region width l smaller than a hole diffusion length ( l < Lp). This is the socalled narrow base diode. Since for this case holes are injected in

Hw5_solutions
School: University Of Illinois, Urbana Champaign
ECE440 HomeworkV Summer2006 14 3 1. A1cmlongGebarhasalinearacceptordistributionNA=10 (1+ax)/cm ,wherea= 10/mm. (a)Plottheholecarrierdistributionatequilibriumat300Kfromx=0to1cm. Theapproximation p0 N A isvalidif N A n i .Sincetheminimumvalueofthevariable d

Hw8_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VIII Solutions + Summer 2006 17 3 1. A p n silicon diode (Vo = 0.956 volts) has a donor doping of 2x10 /cm and nregion width = 1 m. Does it break down by avalanche or punchthrough? What if the 16 3 doping is only 1.5x10 /cm ? Refer to Fi

Hw10
School: University Of Illinois, Urbana Champaign
ECE 440 Homework X Summer 2006 Due: Thursday, July 27, 2006 1. Redraw Fig. 612 for the pchannel (ntype substrate) case. Also include schematic drawings showing the electric circuit and contact configurations. 15 3 2. An ideal MOS capacitor which is mad

Exam1
School: University Of Illinois, Urbana Champaign

Hw8
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VIII Due: Monday, July 17, 2006 + Summer 2006 17 3 1. A p n silicon diode (Vo = 0.956 volts) has a donor doping of 2x10 /cm and nregion width = 1 m. Does it break down by avalanche or punchthrough? What if the 16 3 doping is only 1.5x10

Hw6_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VI 17 Summer 2006 3 15 3 1. An abrupt Si pn junction has NA = 3 x 10 /cm on the pside and ND = 2x10 /cm on the nside. (a) Calculate the Fermi level positions in the p and n regions at 300 K. P region: (1) Ei E f = 3 1017 kT p ln = .0

Hw7_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VII 17 3 Summer 2006 15 3 1. A Si step junction has NA = 10 /cm , ND = 8 x 10 /cm and a crosssectional area 4 2 8 7 of 10 cm . Assume that minority carrier life times n = 10 sec and p = 10 sec. The diode is forward biased at V = (2/3)

Hw7
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VII Due: Wednesday, July 12, 2006 17 3 15 Summer 2006 3 1. A Si step junction has NA = 10 /cm , ND = 8 x 10 /cm and a crosssectional area 4 2 8 7 of 10 cm . Assume that minority carrier life times n = 10 sec and p = 10 sec. The diode

Hw11_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XI Fall 2008 Due: Monday, Nov. 17, 2008 1. Redraw Fig. 73 for an n+pn transistor, and explain the various components of carrier flow and current directions. 2. Sketch the energy band diagram for an npn transistor in equilibrium (all

Hw11
School: University Of Illinois, Urbana Champaign
ECE 440 Homework XI Fall 2008 Due: Monday, Nov. 17, 2008 1. Redraw Fig. 73 for an n+pn transistor, and explain the various components of carrier flow and current directions. 2. Sketch the energy band diagram for an npn transistor in equilibrium (all

Hw3_solutions
School: University Of Illinois, Urbana Champaign
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 ntype or ptype material? Why? (b) For a nonstoichiometr

Hw4
School: University Of Illinois, Urbana Champaign
ECE 440 Homework IV Fall 2008 Due: Monday, September 22, 2008 1. In practice we assume that the intrinsic Fermi level, Ei, coincides with the center of the band gap. In reality it is not true. Derive an expression relating the intrinsic level Ei to the ce

Hw2_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework II Fall 2008 Due: Monday, September 08, 2008 1. Gold, one of the best conductors, has a facecentered cubic lattice. The lattice constant is 4.08. The force holding the lattice together is the metallic bonding, i.e. an interaction between

Hw3
School: University Of Illinois, Urbana Champaign
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 ntype or ptype material? Why? (b) For a nonstoichiometr

Hw2
School: University Of Illinois, Urbana Champaign
ECE 440 Homework II Fall 2008 Due: Monday, September 08, 2008 1. Gold, one of the best conductors, has a facecentered cubic lattice. The lattice constant is 4.08. The force holding the lattice together is the metallic bonding, i.e. an interaction between

Hw1_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework I Solutions Fall2008 1. How many atoms are found inside a unit cell of a simple cubic (sc), bodycentered cubic (bcc), facecentered cubic (fcc), diamond structure, and zincblende structure crystal? Find the maximum fractions of the unit

Hw1
School: University Of Illinois, Urbana Champaign
ECE 440 Homework I Fall 2008 Due: Wednesday, September 03, 2008 1. How many atoms are found inside a unit cell of a simple cubic (sc), bodycentered cubic (bcc), facecentered cubic (fcc), diamond structure, and zincblende structure crystal? Find the max

Formula
School: University Of Illinois, Urbana Champaign

Hw7_solutions
School: University Of Illinois, Urbana Champaign
ECE 440 Homework VII Fall 2008 Due: Monday, October 20, 2008 1. An abrupt Si pn junction has Na = 6x1016/cm3 on the pside and Nd = 2x1017/cm3 on the nside. (a) Calculate the Fermi level positions at 300 K in the p and n regions. P region: (1) Ei Ef = kT