Semiconductor Device Physics Lecture 1 Dr Ing Erwin

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Semiconductor Device Physics Lecture 1 Dr. -Ing. Erwin Sitompul President University http: //zitompul. wordpress.

Semiconductor Device Physics Lecture 1 Dr. -Ing. Erwin Sitompul President University http: //zitompul. wordpress. com President University Erwin Sitompul SDP 1/1

Semiconductor Device Physics Textbook and Syllabus Textbook: “Semiconductor Device Fundamentals”, Robert F. Pierret, International

Semiconductor Device Physics Textbook and Syllabus Textbook: “Semiconductor Device Fundamentals”, Robert F. Pierret, International Edition, Addison Wesley, 1996. Syllabus: Chapter 1: Semiconductors: A General Introduction Chapter 2: Carrier Modeling Chapter 3: Carrier Action Chapter 5: pn Junction Electrostatics Chapter 6: pn Junction Diode: I–V Characteristics Chapter 7: pn Junction Diode: Small-Signal Admittance Chapter 8: pn Junction Diode: Transient Response Chapter 14: MS Contacts and Schottky Diodes Chapter 9: Optoelectronic Diodes Chapter 10: BJT Fundamentals Chapter 11: BJT Static Characteristics Chapter 12: BJT Dynamic Response Modeling President University Erwin Sitompul SDP 1/2

Semiconductor Device Physics Grade Policy: Final Grade = 10% Homework + 20% Quizzes +

Semiconductor Device Physics Grade Policy: Final Grade = 10% Homework + 20% Quizzes + 30% Midterm Exam + 40% Final Exam + Extra Points § Homeworks will be given in fairly regular basis. The average of homework grades contributes 10% of final grade. § Homeworks are to be written on A 4 papers, otherwise they will not be graded. § Homeworks must be submitted on time. If you submit late, < 10 min. No penalty 10 – 60 min. – 20 points > 60 min. – 40 points § There will be 3 quizzes. Only the best 2 will be counted. The average of quiz grades contributes 20% of final grade. President University Erwin Sitompul SDP 1/3

Semiconductor Device Physics Grade Policy • Heading of Homework Papers (Required) Grade Policy: §

Semiconductor Device Physics Grade Policy • Heading of Homework Papers (Required) Grade Policy: § Midterm and final exam schedule will be announced in time. § Make up of quizzes and exams will be held one week after the schedule of the respective quizzes and exams. § The score of a make up quiz or exam can be multiplied by 0. 9 (the maximum score for a make up is 90). President University Erwin Sitompul SDP 1/4

Semiconductor Device Physics Grade Policy: § Extra points will be given every time you

Semiconductor Device Physics Grade Policy: § Extra points will be given every time you solve a problem in front of the class. You will earn 1 or 2 points. § Lecture slides can be copied during class session. It also will be available on internet around 3 days after class. Please check the course homepage regularly. http: //zitompul. wordpress. com President University Erwin Sitompul SDP 1/5

Chapter 1 Semiconductors: A General Introduction What is a Semiconductor? n Low resistivity “conductor”

Chapter 1 Semiconductors: A General Introduction What is a Semiconductor? n Low resistivity “conductor” n High resistivity “insulator” n Intermediate resistivity “semiconductor” n The conductivity (and at the same time the resistivity) of semiconductors lie between that of conductors and insulators. President University Erwin Sitompul SDP 1/6

Chapter 1 Semiconductors: A General Introduction What is a Semiconductor? n Semiconductors are some

Chapter 1 Semiconductors: A General Introduction What is a Semiconductor? n Semiconductors are some of the purest solid materials in existence, because any trace of impurity atoms called “dopants” can change the electrical properties of semiconductors drastically. n Unintentional impurity level: 1 impurity atom per 109 semiconductor atom. n Intentional impurity ranging from 1 per 108 to 1 per 103. No recognizable long-range order Entire solid is made up of atoms in an orderly three- dimensional array Completely ordered in segments polycrystalline amorphous crystalline n Most devices fabricated today employ crystalline semiconductors. President University Erwin Sitompul SDP 1/7

Chapter 1 Semiconductors: A General Introduction Semiconductor Materials Elemental: Si, Ge, C Compound: IV-IV

Chapter 1 Semiconductors: A General Introduction Semiconductor Materials Elemental: Si, Ge, C Compound: IV-IV III-VI Alloy: Si 1 -x. Gex Alx. Ga 1 -x. As President University Si. C Ga. As, Ga. N Cd. Se Erwin Sitompul SDP 1/8

Chapter 1 Semiconductors: A General Introduction From Hydrogen to Silicon President University Erwin Sitompul

Chapter 1 Semiconductors: A General Introduction From Hydrogen to Silicon President University Erwin Sitompul SDP 1/9

Chapter 1 Semiconductors: A General Introduction The Silicon Atom n 14 electrons occupying the

Chapter 1 Semiconductors: A General Introduction The Silicon Atom n 14 electrons occupying the first 3 energy levels: n 1 s, 2 p orbitals are filled by 10 electrons. n 3 s, 3 p orbitals filled by 4 electrons. n To minimize the overall energy, the 3 s and 3 p orbitals hybridize to form four tetrahedral 3 sp orbital. n Each has one electron and is capable of forming a bond with a neighboring atom. President University Erwin Sitompul SDP 1/10

Chapter 1 Semiconductors: A General Introduction The Si Crystal • Each Si atom has

Chapter 1 Semiconductors: A General Introduction The Si Crystal • Each Si atom has 4 nearest • neighbors. Atom lattice constant (length of the unit cell side) ° 1 A=10 ° – 10 m a = 5. 431 A, • Each cell contains: 8 corner atoms 6 face atoms 4 interior atoms a “Diamond Lattice” President University Erwin Sitompul SDP 1/11

Chapter 1 Semiconductors: A General Introduction How Many Silicon Atoms per cm– 3? n

Chapter 1 Semiconductors: A General Introduction How Many Silicon Atoms per cm– 3? n Number of atoms in a unit cell: n 4 atoms completely inside cell n Each of the 8 atoms on corners are shared among 8 cells count as 1 atom inside cell n Each of the 6 atoms on the faces are shared among 2 cells count as 3 atoms inside cell Total number inside the cell = 4 + 1 + 3 = 8 n Cell volume = (. 543 nm)3 = 1. 6 x 10– 22 cm 3 n Density of silicon atom = (8 atoms) / (cell volume) = 5 x 1022 atoms/cm 3 President University Erwin Sitompul SDP 1/12

Chapter 1 Semiconductors: A General Introduction Compound Semiconductors n “Zincblende” structure n III-V compound

Chapter 1 Semiconductors: A General Introduction Compound Semiconductors n “Zincblende” structure n III-V compound semiconductors: Ga. As, Ga. P, Ga. N, etc. President University Erwin Sitompul SDP 1/13

Chapter 1 Semiconductors: A General Introduction Crystallographic Notation Miller Indices Notation Interpretation (hkl) crystal

Chapter 1 Semiconductors: A General Introduction Crystallographic Notation Miller Indices Notation Interpretation (hkl) crystal plane {hkl} equivalent planes [hkl] crystal direction <hkl> equivalent directions h: inverse x-intercept of plane k: inverse y-intercept of plane l: inverse z-intercept of plane (h, k and l are reduced to 3 integers having the same ratio. ) President University Erwin Sitompul SDP 1/14

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes (632) plane President University (001) plane

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes (632) plane President University (001) plane Erwin Sitompul _ (221) plane SDP 1/15

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes President University Erwin Sitompul SDP 1/16

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes President University Erwin Sitompul SDP 1/16

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes of Si Wafers n Silicon wafers

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes of Si Wafers n Silicon wafers are usually cut along a {100} plane with a flat or notch to orient the wafer during integrated-circuit fabrication. n The facing surface is polished and etched yielding mirror-like finish. President University Erwin Sitompul SDP 1/17

Chapter 1 Semiconductors: A General Introduction Crystal Growth Until Device Fabrication President University Erwin

Chapter 1 Semiconductors: A General Introduction Crystal Growth Until Device Fabrication President University Erwin Sitompul SDP 1/18

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes of Si Unit cell: View in

Chapter 1 Semiconductors: A General Introduction Crystallographic Planes of Si Unit cell: View in <111> direction View in <100> direction President University View in <110> direction Erwin Sitompul SDP 1/19

Chapter 1 Semiconductors: A General Introduction Greek Alphabet —new —zz-eye —pie —taw —fie —k-eye

Chapter 1 Semiconductors: A General Introduction Greek Alphabet —new —zz-eye —pie —taw —fie —k-eye —sigh —mew President University Erwin Sitompul SDP 1/20