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Unformatted text preview: ‘yl October 31, 2003
University of Saskatchewan
Department of Electrical Engineering EE372 Electronic Materials and Devices
Midterm Examination
Professor Robert E. Johanson PART B
(open textbook) Name: ((o/ Student Number: [p/é Welcome to the EE372 Midterm. The examination has two parts. Part A consists of
questions that test knowledge of basic concepts, and part B requires more involved
calculations. Part A is closed book and closed notes. When you ﬁnish part A, hand it in
(raise your hand) and then proceed to part B. Part B is open book; you may refer to your
textbook (Kasap, any edition) but not to any other material such as notes or other books.
You may also use a calculator for both parts. The examination lasts 2 hours. Each problem is weighted equally. Show your work if the question involves more than a
simple answer; credit will be given only if the steps leading to the answer are clearly
shown. Partial credit will be given for partially correct answers but only if correct
intermediate steps are shown. Write your answers on these pages. For part B, answer 3 of the 4 questions. Do not answer more than 3 questions.
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0 total 13 / 39 PHYSICAL CONSTANTS c = 29979wa m 53
e =1.6021x1019 C
me = 9.1091x10'31 kg
h = 6.62608x10'34 J s
k = 1.3807x1023 J K1 . £0 = 8.8542x1012 F m1 ﬂSemiconductor Statistics 3) A silicon crystal is uniformly doped with 3x10l6 cm'3 of boron acceptors. What is the
density of holes in the valence band and electrons in the conduction band? Calculate the position of the Fermi level with respect to the valence band edge E at T \1 b) The above silicon crystal is ion implanted with 2x 1017 cm'3 phosphorous donor atoms creating compensated silicon. What is the density of holes in the valence band and
electrons in the conduction band now? Calculate the new position of the Fermi level with respect to the conduction band edge EC. ‘ lo ’3
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(0 Quantum Tunneling An insulator in an electronic device presents a potential barrier that is 10 eV high. If the v electrons’ energy is 5 eV, how thick must the insulator be so that the probability of
tunneling through the barrier is 0.05? Mac; \
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11 is illuminated with light such that the A piece of ntype Si is doped with 1
(minority carrier) lifetime is 1 us. The ' '
generation rate is G = 3 x1020 cm'3 ' . ier) and hole (minority carrier) / a) What are the steadystate ctron (majority c
densities while the silico s illuminated? b) The electron ole mobilities are ye = 1300 csz '1 and ,uh = 450 csz'ls'1
What is the c ductivity of the silicon in darkness and durin illumination? _/ (9%" «3 IS
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This note was uploaded on 01/20/2011 for the course EE 372 taught by Professor Johanson/kasap during the Fall '10 term at University of Saskatchewan Management Area.
 Fall '10
 Johanson/Kasap

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