8. Schottky contacts / JFETs
|
|
- Maude Oliver
- 3 years ago
- Views:
Transcription
1 Technische Universität Graz Institute of Solid State Physics 8. Schottky contacts / JFETs Nov. 21, 2018
2 Technische Universität Graz Institute of Solid State Physics metal - semiconductor contacts Photoelectric effect Schottky barriers Schottky diodes Ohmic contacts Thermionic emission Tunnel contacts
3 Photoelectric effect hf 0 = e at threshold current workfunction f threshold frequency f 0
4 Singh There is a dipole field at the surface of a metal. This electric field must be overcome for an electron to escape.
5 work function - electron affinity If s < m, the semiconductor bands bend down. If s > m, the semiconductor bands bend up.
6 Singh
7
8 p-type Walter Schottky Schottky contact / ohmic contact E F,m metal E F,s Schottky contact E F,m metal E F,s Ohmic contact: linear resistance specific contact resistance: R c J V 1 -cm 2
9 n-type Schottky contact / ohmic contact E F,s Schottky contact E F,m metal E F,m metal E F,s Ohmic contact: linear resistance specific contact resistance: R c J V 1 -cm 2
10 Interface states b metal Interface states
11
12 Schottky barrier en D E x xn r 0 W x n 2 Vbi en V D V en D x 2 2 xx n
13 CV measurements x p 2 Vbi en V A e NA C x 2 V V p bi C bi V V e N A -2 F m GaAs has larger E g and V bi 1/C 2 ev V Nv ln ( T k T ) N A bi b B
14 Thermionic emission 1901 Richardson Owen Willans Richardson Current from a heated wire is: J A 2 RT exp e kt B Some electrons have a thermal energy that exceeds the work function and escape from the wire.
15 diode Vacuum diodes
16 Thermionic emission Fermi function ev bi V E F EF E E F E E f( E) exp exp exp exp kt B kt B kt B kt B The density of electrons with enough energy to go over the barriers E exp kt B
17 Thermionic emission n th ev exp kt B I sm ev nth exp kt B I ( 0) ms Ism V ev kt B I Ism Ims Ims e 1
18 Schottky barrier Forward bias Reverse bias b e(v bi - V) ev b ev e(v bi - V) I sm > I ms I sm ~ exp(ev/k B T) I ms constant I sm ~ 0 I ms constant
19 Thermionic emission ev B I I e kt sm Ims I s 1 Nonideality factor = 1
20 Thermionic emission I s * e 2 b AART exp kt B A = Area A R* = Richardson constant n-si A * R = 110 A K -2 cm -2 p-si A * R = 32 A K -2 cm -2 n-gaas A * R = 8 A K -2 cm -2 p-gaas A * R = 74 A K -2 cm -2 Thermionic emission dominates over diffusion current in a Schottky diode.
21 Schottky diodes Majority carrier current dominates. nonideality factor = 1. Fast response, no recombination of electron-hole pairs required. Used as rf mixers. Low turn on voltage - high reverse bias current ev B I I e kt s 1
22 Tunnel contacts For high doping, the Schottky barrier is so thin that electrons can tunnel through it. metal p+ p Degenerate doping at a tunnel contact metal n+ n Tunnel contacts have a linear resistance.
23 Contacts
24 Transport mechanisms Drift Diffusion Thermionic emission Tunneling All mechanisms are always present. One or two transport mechanisms can dominate depending on the device and the bias conditions. In a forward biased pn-junction, diffusion dominates. In a tunnel contact, tunneling dominates. In a Schottky diode, thermionic emission dominates.
25 Technische Universität Graz Institute of Solid State Physics JFETs - MESFETs - MODFETs Junction Field Effect Transistors (JFET) Metal-Semiconductor Field Effect Transistors (MESFET) Modulation Doped Field Effect Transistors (MODFET) n
26 JFET n-channel JFET n For N A >> N D 2 ( ) x n Vbi V en D Depletion mode h x n 2Vbi en D conducting at V g = 0 Enhancement mode h x n 2V bi en D nonconducting at V g = 0
27 depletion zone n-channel (power) JFET
28 Power SiC JFET p n p
29 n-channel JFET drain p+ n+ depletion region p n p gate n+ source JFETs are often discrete devices
30 MESFET Metal-Semiconductor Field Effect Transistors n Depletion layer created by Schottky barrier x n 2 ( Vbi V) en D Fast transistors can be realized in n-channel GaAs, however GaAs has a low hole mobility making p-channel devices slower.
31 JFET n D n-channel JFET D G S n-channel JFET x n 2 ( Vbi V) en D G S p-channel JFET 2 Pinch-off at h = x en n Dh Vp 2 V p = pinch-off voltage At Pinch-off, V= V bi -V p.
Schottky diodes. JFETs - MESFETs - MODFETs
Technische Universität Graz Institute of Solid State Physics Schottky diodes JFETs - MESFETs - MODFETs Quasi Fermi level When the charge carriers are not in equilibrium the Fermi energy can be different
Avalanche breakdown. Impact ionization causes an avalanche of current. Occurs at low doping
Avalanche breakdown Impact ionization causes an avalanche of current Occurs at low doping Zener tunneling Electrons tunnel from valence band to conduction band Occurs at high doping Tunneling wave decays
Current mechanisms Exam January 27, 2012
Current mechanisms Exam January 27, 2012 There are four mechanisms that typically cause currents to flow: thermionic emission, diffusion, drift, and tunneling. Explain briefly which kind of current mechanisms
Schottky Rectifiers Zheng Yang (ERF 3017,
ECE442 Power Semiconductor Devices and Integrated Circuits Schottky Rectifiers Zheng Yang (ERF 3017, email: yangzhen@uic.edu) Power Schottky Rectifier Structure 2 Metal-Semiconductor Contact The work function
Spring Semester 2012 Final Exam
Spring Semester 2012 Final Exam Note: Show your work, underline results, and always show units. Official exam time: 2.0 hours; an extension of at least 1.0 hour will be granted to anyone. Materials parameters
PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS
PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS Tennessee Technological University Monday, November 11, 013 1 Introduction Chapter 4: we considered the semiconductor
PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS
PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS Tennessee Technological University Wednesday, October 30, 013 1 Introduction Chapter 4: we considered the
Semiconductor Device Physics
1 emiconductor Device Physics Lecture 8 http://zitompul.wordpress.com 2 0 1 3 emiconductor Device Physics 2 M Contacts and chottky Diodes 3 M Contact The metal-semiconductor (M) contact plays a very important
Institute of Solid State Physics. Technische Universität Graz. Exam. Feb 2, 10:00-11:00 P2
Technische Universität Graz nstitute of Solid State Physics Exam Feb 2, 10:00-11:00 P2 Exam Four questions, two from the online list. Calculator is ok. No notes. Explain some concept: (tunnel contact,
Chapter 7. The pn Junction
Chapter 7 The pn Junction Chapter 7 PN Junction PN junction can be fabricated by implanting or diffusing donors into a P-type substrate such that a layer of semiconductor is converted into N type. Converting
Consider a uniformly doped PN junction, in which one region of the semiconductor is uniformly doped with acceptor atoms and the adjacent region is
CHAPTER 7 The PN Junction Consider a uniformly doped PN junction, in which one region of the semiconductor is uniformly doped with acceptor atoms and the adjacent region is uniformly doped with donor atoms.
Semiconductor Physics and Devices
The pn Junction 1) Charge carriers crossing the junction. 3) Barrier potential Semiconductor Physics and Devices Chapter 8. The pn Junction Diode 2) Formation of positive and negative ions. 4) Formation
EECS130 Integrated Circuit Devices
EECS130 Integrated Circuit Devices Professor Ali Javey 10/02/2007 MS Junctions, Lecture 2 MOS Cap, Lecture 1 Reading: finish chapter14, start chapter16 Announcements Professor Javey will hold his OH at
Memories Bipolar Transistors
Technische Universität Graz nstitute of Solid State Physics Memories Bipolar Transistors Technische Universität Graz nstitute of Solid State Physics Exams February 5 March 7 April 18 June 27 Exam Four
Semiconductor Devices
Semiconductor Devices - 2014 Lecture Course Part of SS Module PY4P03 Dr. P. Stamenov School of Physics and CRANN, Trinity College, Dublin 2, Ireland Hilary Term, TCD 17 th of Jan 14 Metal-Semiconductor
Figure 3.1 (p. 141) Figure 3.2 (p. 142)
Figure 3.1 (p. 141) Allowed electronic-energy-state systems for two isolated materials. States marked with an X are filled; those unmarked are empty. System 1 is a qualitative representation of a metal;
Metal Semiconductor Contacts
Metal Semiconductor Contacts The investigation of rectification in metal-semiconductor contacts was first described by Braun [33-35], who discovered in 1874 the asymmetric nature of electrical conduction
JFETs - MESFETs - MODFETs
Technische Universität raz Institute of Solid State Physics JFETs - MESFETs - MOFETs JFET n n-channel JFET S n-channel JFET x n 2 ( Vbi V) en S p-channel JFET 2 Pinch-off at h = x en n h Vp 2 V p = pinch-off
JFET/MESFET. JFET: small gate current (reverse leakage of the gate-to-channel junction) More gate leakage than MOSFET, less than bipolar.
JFET/MESFET JFET: small gate current (reverse leakage of the gate-to-channel junction) More gate leakage than MOSFET, less than bipolar. JFET has higher transconductance than the MOSFET. Used in low-noise,
ECE 340 Lecture 35 : Metal- Semiconductor Junctions Class Outline:
ECE 340 Lecture 35 : - Junctions Class Outline: Ideal - Contacts Rectifying Contacts Ohmic Contacts Things you should know when you leave Key Questions What happens to the bands when we make contact between
1 Name: Student number: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND. Fall :00-11:00
1 Name: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND Final Exam Physics 3000 December 11, 2012 Fall 2012 9:00-11:00 INSTRUCTIONS: 1. Answer all seven (7) questions.
Physics of Semiconductors 8 th
Physics of Semiconductors 8 th 2016.6.6 Shingo Katsumoto Department of Physics, Institute for Solid State Physics University of Tokyo Review of pn junction Estimation of builtin potential Depletion layer
Problem 9.20 Threshold bias for an n-channel MOSFET: In the text we used a criterion that the inversion of the MOSFET channel occurs when V s = ;2 F w
Prof. Jasprit Singh Fall 2001 EECS 320 Homework 11 The nals for this course are set for Friday December 14, 6:30 8:30 pm and Friday Dec. 21, 10:30 am 12:30 pm. Please choose one of these times and inform
Session 6: Solid State Physics. Diode
Session 6: Solid State Physics Diode 1 Outline A B C D E F G H I J 2 Definitions / Assumptions Homojunction: the junction is between two regions of the same material Heterojunction: the junction is between
MOS Capacitors ECE 2204
MOS apacitors EE 2204 Some lasses of Field Effect Transistors Metal-Oxide-Semiconductor Field Effect Transistor MOSFET, which will be the type that we will study in this course. Metal-Semiconductor Field
Semiconductor Physics fall 2012 problems
Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each
n N D n p = n i p N A
Summary of electron and hole concentration in semiconductors Intrinsic semiconductor: E G n kt i = pi = N e 2 0 Donor-doped semiconductor: n N D where N D is the concentration of donor impurity Acceptor-doped
Introductory Nanotechnology ~ Basic Condensed Matter Physics ~
Introductory Nanotechnology ~ Basic Condensed Matter Physics ~ Atsufumi Hirohata Department of Electronics Quick Review over the Last Lecture Classic model : Dulong-Petit empirical law c V, mol 3R 0 E
Introduction to Power Semiconductor Devices
ECE442 Power Semiconductor Devices and Integrated Circuits Introduction to Power Semiconductor Devices Zheng Yang (ERF 3017, email: yangzhen@uic.edu) Power Semiconductor Devices Applications System Ratings
3. Two-dimensional systems
3. Two-dimensional systems Image from IBM-Almaden 1 Introduction Type I: natural layered structures, e.g., graphite (with C nanostructures) Type II: artificial structures, heterojunctions Great technological
GaN based transistors
GaN based transistors S FP FP dielectric G SiO 2 Al x Ga 1-x N barrier i-gan Buffer i-sic D Transistors "The Transistor was probably the most important invention of the 20th Century The American Institute
12. Memories / Bipolar transistors
Technische Universität Graz Institute of Solid State Physics 12. Memories / Bipolar transistors Jan. 9, 2019 Technische Universität Graz Institute of Solid State Physics Exams January 31 March 8 May 17
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences. EECS 130 Professor Ali Javey Fall 2006
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EECS 130 Professor Ali Javey Fall 2006 Midterm 2 Name: SID: Closed book. Two sheets of notes are
Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination
Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination The Metal-Semiconductor Junction: Review Energy band diagram of the metal and the semiconductor before (a)
Session 0: Review of Solid State Devices. From Atom to Transistor
Session 0: Review of Solid State Devices From Atom to Transistor 1 Objective To Understand: how Diodes, and Transistors operate! p n p+ n p- n+ n+ p 2 21 Century Alchemy! Ohm s law resistivity Resistivity
Semiconductor Physics. Lecture 6
Semiconductor Physics Lecture 6 Recap pn junction and the depletion region Driven by the need to have no gradient in the fermi level free carriers migrate across the pn junction leaving a region with few
Section 12: Intro to Devices
Section 12: Intro to Devices Extensive reading materials on reserve, including Robert F. Pierret, Semiconductor Device Fundamentals Bond Model of Electrons and Holes Si Si Si Si Si Si Si Si Si Silicon
Semiconductor Physical Electronics
Semiconductor Physical Electronics Sheng S. Li Department of Electrical Engineering University of Florida Gainesville, Florida Plenum Press New York and London Contents CHAPTER 1. Classification of Solids
Theory of Electrical Characterization of Semiconductors
Theory of Electrical Characterization of Semiconductors P. Stallinga Universidade do Algarve U.C.E.H. A.D.E.E.C. OptoElectronics SELOA Summer School May 2000, Bologna (It) Overview Devices: bulk Schottky
Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes
Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes Problem 1: Semiconductor Fundamentals [30 points] A uniformly doped silicon sample of length 100µm and cross-sectional area 100µm 2
Lecture 9: Metal-semiconductor junctions
Lecture 9: Metal-semiconductor junctions Contents 1 Introduction 1 2 Metal-metal junction 1 2.1 Thermocouples.......................... 2 3 Schottky junctions 4 3.1 Forward bias............................
Semiconductor Physics Problems 2015
Semiconductor Physics Problems 2015 Page and figure numbers refer to Semiconductor Devices Physics and Technology, 3rd edition, by SM Sze and M-K Lee 1. The purest semiconductor crystals it is possible
- A free electron in CB "meets" a hole in VB: the excess energy -> a photon energy.
5.4. Recombination and Minority Carrier Injection 5.4.1 Direct and Indirect Recombination A free electron in CB "meets" a hole in VB: the excess energy > a photon energy. Energy CB ψ cb (k cb ) ψ vb (k
Lecture 04 Review of MOSFET
ECE 541/ME 541 Microelectronic Fabrication Techniques Lecture 04 Review of MOSFET Zheng Yang (ERF 3017, email: yangzhen@uic.edu) What is a Transistor? A Switch! An MOS Transistor V GS V T V GS S Ron D
MTLE-6120: Advanced Electronic Properties of Materials. Semiconductor p-n junction diodes. Reading: Kasap ,
MTLE-6120: Advanced Electronic Properties of Materials 1 Semiconductor p-n junction diodes Reading: Kasap 6.1-6.5, 6.9-6.12 Metal-semiconductor contact potential 2 p-type n-type p-type n-type Same semiconductor
* motif: a single or repeated design or color
Chapter 2. Structure A. Electronic structure vs. Geometric structure B. Clean surface vs. Adsorbate covered surface (substrate + overlayer) C. Adsorbate structure - how are the adsorbed molecules bound
Lecture 12: MOS Capacitors, transistors. Context
Lecture 12: MOS Capacitors, transistors Context In the last lecture, we discussed PN diodes, and the depletion layer into semiconductor surfaces. Small signal models In this lecture, we will apply those
MENA9510 characterization course: Capacitance-voltage (CV) measurements
MENA9510 characterization course: Capacitance-voltage (CV) measurements 30.10.2017 Halvard Haug Outline Overview of interesting sample structures Ohmic and schottky contacts Why C-V for solar cells? The
Classification of Solids
Classification of Solids Classification by conductivity, which is related to the band structure: (Filled bands are shown dark; D(E) = Density of states) Class Electron Density Density of States D(E) Examples
EE 3329 Electronic Devices Syllabus ( Extended Play )
EE 3329 - Electronic Devices Syllabus EE 3329 Electronic Devices Syllabus ( Extended Play ) The University of Texas at El Paso The following concepts can be part of the syllabus for the Electronic Devices
For the following statements, mark ( ) for true statement and (X) for wrong statement and correct it.
Benha University Faculty of Engineering Shoubra Electrical Engineering Department First Year communications. Answer all the following questions Illustrate your answers with sketches when necessary. The
Part 1: MetalMetal Contacts Workfunction Differences Flat band (a) (Pt) = 5.36 ev Pt Vacuum Fermi level Electrons Mo Vacuum Fermi level Electrons (Mo)
Applications Using Band Diagrams and Fermi Energy Level Applications to Devices Physics Physics Homojunctions Heterojunctions pn junction metals/c junctions diodes pnp junction pnp Bipolar transistors
Appendix 1: List of symbols
Appendix 1: List of symbols Symbol Description MKS Units a Acceleration m/s 2 a 0 Bohr radius m A Area m 2 A* Richardson constant m/s A C Collector area m 2 A E Emitter area m 2 b Bimolecular recombination
Transistors - a primer
ransistors - a primer What is a transistor? Solid-state triode - three-terminal device, with voltage (or current) at third terminal used to control current between other two terminals. wo types: bipolar
Effective masses in semiconductors
Effective masses in semiconductors The effective mass is defined as: In a solid, the electron (hole) effective mass represents how electrons move in an applied field. The effective mass reflects the inverse
MOS Capacitor MOSFET Devices. MOSFET s. INEL Solid State Electronics. Manuel Toledo Quiñones. ECE Dept. UPRM.
INEL 6055 - Solid State Electronics ECE Dept. UPRM 20th March 2006 Definitions MOS Capacitor Isolated Metal, SiO 2, Si Threshold Voltage qφ m metal d vacuum level SiO qχ 2 E g /2 qφ F E C E i E F E v qφ
Fundamentals of Semiconductor Physics
Fall 2007 Fundamentals of Semiconductor Physics 万 歆 Zhejiang Institute of Modern Physics xinwan@zimp.zju.edu.cn http://zimp.zju.edu.cn/~xinwan/ Transistor technology evokes new physics The objective of
9. Semiconductor Devices /Phonons
Technische Universität Graz Institute of Solid State Physics 9. Semiconductor Devices /Phonons Oct 29, 2018 p and n profiles p n V bi ~ 1 V E c W ~ 1 m E F E max ~ 10 4 V/cm ev bi E v p Ev E F Nv exp kt
ρ ρ LED access resistances d A W d s n s p p p W the output window size p-layer d p series access resistance d n n-layer series access resistance
LED access resistances W the output window size p-layer series access resistance d p n-layer series access resistance d n The n-layer series access resistance R = ρ s n where the resistivity of the n-layer
Lecture 2. Introduction to semiconductors Structures and characteristics in semiconductors. Fabrication of semiconductor sensor
Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Fabrication of semiconductor sensor
Sheng S. Li. Semiconductor Physical Electronics. Second Edition. With 230 Figures. 4) Springer
Sheng S. Li Semiconductor Physical Electronics Second Edition With 230 Figures 4) Springer Contents Preface 1. Classification of Solids and Crystal Structure 1 1.1 Introduction 1 1.2 The Bravais Lattice
Thermionic emission vs. drift-diffusion vs. p-n junction
6.772/SMA5111 - Compound Semiconductors Lecture 4 - Carrier flow in heterojunctions - Outline A look at current models for m-s junctions (old business) Thermionic emission vs. drift-diffusion vs. p-n junction
Sample Exam # 2 ECEN 3320 Fall 2013 Semiconductor Devices October 28, 2013 Due November 4, 2013
Sample Exam # 2 ECEN 3320 Fall 203 Semiconductor Devices October 28, 203 Due November 4, 203. Below is the capacitance-voltage curve measured from a Schottky contact made on GaAs at T 300 K. Figure : Capacitance
EECS130 Integrated Circuit Devices
EECS130 Integrated Circuit Devices Professor Ali Javey 9/18/2007 P Junctions Lecture 1 Reading: Chapter 5 Announcements For THIS WEEK OLY, Prof. Javey's office hours will be held on Tuesday, Sept 18 3:30-4:30
Lecture 2. Introduction to semiconductors Structures and characteristics in semiconductors
Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Literature Glen F. Knoll, Radiation
Semiconductor Physics fall 2012 problems
Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each
R. Ludwig and G. Bogdanov RF Circuit Design: Theory and Applications 2 nd edition. Figures for Chapter 6
R. Ludwig and G. Bogdanov RF Circuit Design: Theory and Applications 2 nd edition Figures for Chapter 6 Free electron Conduction band Hole W g W C Forbidden Band or Bandgap W V Electron energy Hole Valence
Section 12: Intro to Devices
Section 12: Intro to Devices Extensive reading materials on reserve, including Robert F. Pierret, Semiconductor Device Fundamentals EE143 Ali Javey Bond Model of Electrons and Holes Si Si Si Si Si Si Si
Module-6: Schottky barrier capacitance-impurity concentration
6.1 Introduction: Module-6: Schottky barrier capacitance-impurity concentration The electric current flowing across a metal semiconductor interface is generally non-linear with respect to the applied bias
Thermionic Emission Theory
hapter 4. PN and Metal-Semiconductor Junction Thermionic Emiion Theory Energy band diagram of a Schottky contact with a forward bia V applied between the metal and the emiconductor. Electron concentration
MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University
MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University Practice Final Exam 1 Read the questions carefully Label all figures
The pn junction. [Fonstad, Ghione]
The pn junction [Fonstad, Ghione] Band diagram On the vertical axis: potential energy of the electrons On the horizontal axis: now there is nothing: later we ll put the position qf s : work function (F
MOSFET: Introduction
E&CE 437 Integrated VLSI Systems MOS Transistor 1 of 30 MOSFET: Introduction Metal oxide semiconductor field effect transistor (MOSFET) or MOS is widely used for implementing digital designs Its major
EE 130 Intro to MS Junctions Week 6 Notes. What is the work function? Energy to excite electron from Fermi level to the vacuum level
EE 13 Intro to S Junctions eek 6 Notes Problem 1 hat is the work function? Energy to ecite electron from Fermi level to the vacuum level Electron affinity of 4.5eV Electron affinity of Ge 4.eV orkfunction
Schottky Diodes (M-S Contacts)
Schottky Diodes (M-S Contacts) Three MITs of the Day Band diagrams for ohmic and rectifying Schottky contacts Similarity to and difference from bipolar junctions on electrostatic and IV characteristics.
Semiconductor Integrated Process Design (MS 635)
Semiconductor Integrated Process Design (MS 635) Instructor: Prof. Keon Jae Lee - Office: 응용공학동 #4306, Tel: #3343 - Email: keonlee@kaist.ac.kr Lecture: (Tu, Th), 1:00-2:15 #2425 Office hour: Tues & Thur
Semiconductor Junctions
8 Semiconductor Junctions Almost all solar cells contain junctions between different materials of different doping. Since these junctions are crucial to the operation of the solar cell, we will discuss
Lecture 6: 2D FET Electrostatics
Lecture 6: 2D FET Electrostatics 2016-02-01 Lecture 6, High Speed Devices 2014 1 Lecture 6: III-V FET DC I - MESFETs Reading Guide: Liu: 323-337 (he mainly focuses on the single heterostructure FET) Jena:
CHAPTER 4: P-N P N JUNCTION Part 2. M.N.A. Halif & S.N. Sabki
CHAPTER 4: P-N P N JUNCTION Part 2 Part 2 Charge Storage & Transient Behavior Junction Breakdown Heterojunction CHARGE STORAGE & TRANSIENT BEHAVIOR Once injected across the junction, the minority carriers
Electronic Circuits 1. Transistor Devices. Contents BJT and FET Characteristics Operations. Prof. C.K. Tse: Transistor devices
Electronic Circuits 1 Transistor Devices Contents BJT and FET Characteristics Operations 1 What is a transistor? Three-terminal device whose voltage-current relationship is controlled by a third voltage
junctions produce nonlinear current voltage characteristics which can be exploited
Chapter 6 P-N DODES Junctions between n-and p-type semiconductors are extremely important foravariety of devices. Diodes based on p-n junctions produce nonlinear current voltage characteristics which can
Electrical Characteristics of Multilayer MoS 2 FET s
Electrical Characteristics of Multilayer MoS 2 FET s with MoS 2 /Graphene Hetero-Junction Contacts Joon Young Kwak,* Jeonghyun Hwang, Brian Calderon, Hussain Alsalman, Nini Munoz, Brian Schutter, and Michael
Operation and Modeling of. The MOS Transistor. Second Edition. Yannis Tsividis Columbia University. New York Oxford OXFORD UNIVERSITY PRESS
Operation and Modeling of The MOS Transistor Second Edition Yannis Tsividis Columbia University New York Oxford OXFORD UNIVERSITY PRESS CONTENTS Chapter 1 l.l 1.2 1.3 1.4 1.5 1.6 1.7 Chapter 2 2.1 2.2
Surfaces, Interfaces, and Layered Devices
Surfaces, Interfaces, and Layered Devices Building blocks for nanodevices! W. Pauli: God made solids, but surfaces were the work of Devil. Surfaces and Interfaces 1 Interface between a crystal and vacuum
ECE 340 Lecture 39 : MOS Capacitor II
ECE 340 Lecture 39 : MOS Capacitor II Class Outline: Effects of Real Surfaces Threshold Voltage MOS Capacitance-Voltage Analysis Things you should know when you leave Key Questions What are the effects
Typical example of the FET: MEtal Semiconductor FET (MESFET)
Typical example of the FET: MEtal Semiconductor FET (MESFET) Conducting channel (RED) is made of highly doped material. The electron concentration in the channel n = the donor impurity concentration N
Fundamentals of the Metal Oxide Semiconductor Field-Effect Transistor
Triode Working FET Fundamentals of the Metal Oxide Semiconductor Field-Effect Transistor The characteristics of energy bands as a function of applied voltage. Surface inversion. The expression for the
CLASS 12th. Semiconductors
CLASS 12th Semiconductors 01. Distinction Between Metals, Insulators and Semi-Conductors Metals are good conductors of electricity, insulators do not conduct electricity, while the semiconductors have
Semiconductor Module
Semiconductor Module Optics Seminar July 18, 2018 Yosuke Mizuyama, Ph.D. COMSOL, Inc. The COMSOL Product Suite Governing Equations Semiconductor Schrödinger Equation Semiconductor Optoelectronics, FD Semiconductor
Solid State Physics SEMICONDUCTORS - IV. Lecture 25. A.H. Harker. Physics and Astronomy UCL
Solid State Physics SEMICONDUCTORS - IV Lecture 25 A.H. Harker Physics and Astronomy UCL 9.9 Carrier diffusion and recombination Suppose we have a p-type semiconductor, i.e. n h >> n e. (1) Create a local
MOS Transistor I-V Characteristics and Parasitics
ECEN454 Digital Integrated Circuit Design MOS Transistor I-V Characteristics and Parasitics ECEN 454 Facts about Transistors So far, we have treated transistors as ideal switches An ON transistor passes
CME 300 Properties of Materials. ANSWERS: Homework 9 November 26, As atoms approach each other in the solid state the quantized energy states:
CME 300 Properties of Materials ANSWERS: Homework 9 November 26, 2011 As atoms approach each other in the solid state the quantized energy states: are split. This splitting is associated with the wave
ECE-305: Fall 2017 Metal Oxide Semiconductor Devices
C-305: Fall 2017 Metal Oxide Semiconductor Devices Pierret, Semiconductor Device Fundamentals (SDF) Chapters 15+16 (pp. 525-530, 563-599) Professor Peter Bermel lectrical and Computer ngineering Purdue
Lecture 5 Junction characterisation
Lecture 5 Junction characterisation Jon Major October 2018 The PV research cycle Make cells Measure cells Despair Repeat 40 1.1% 4.9% Data Current density (ma/cm 2 ) 20 0-20 -1.0-0.5 0.0 0.5 1.0 Voltage
Quantum Phenomena & Nanotechnology (4B5)
Quantum Phenomena & Nanotechnology (4B5) The 2-dimensional electron gas (2DEG), Resonant Tunneling diodes, Hot electron transistors Lecture 11 In this lecture, we are going to look at 2-dimensional electron
III.6. METAL SEMICONDUCTOR CONTACT BIAS
.6. MEAL SEMCONUCOR CONAC BAS 1. Work purpose he determination of the potential difference that appears at the contact surface between a metal and a semiconductor, potential difference that is known under
Electron Energy, E E = 0. Free electron. 3s Band 2p Band Overlapping energy bands. 3p 3s 2p 2s. 2s Band. Electrons. 1s ATOM SOLID.
Electron Energy, E Free electron Vacuum level 3p 3s 2p 2s 2s Band 3s Band 2p Band Overlapping energy bands Electrons E = 0 1s ATOM 1s SOLID In a metal the various energy bands overlap to give a single
Peak Electric Field. Junction breakdown occurs when the peak electric field in the PN junction reaches a critical value. For the N + P junction,
Peak Electric Field Junction breakdown occurs when the peak electric field in the P junction reaches a critical value. For the + P junction, qa E ( x) ( xp x), s W dep 2 s ( bi Vr ) 2 s potential barrier
! PN Junction. ! MOS Transistor Topology. ! Threshold. ! Operating Regions. " Resistive. " Saturation. " Subthreshold (next class)
ESE370: ircuitlevel Modeling, Design, and Optimization for Digital Systems Lec 7: September 20, 2017 MOS Transistor Operating Regions Part 1 Today! PN Junction! MOS Transistor Topology! Threshold! Operating
Misan University College of Engineering Electrical Engineering Department. Exam: Final semester Date: 17/6/2017
Misan University College of Engineering Electrical Engineering Department Subject: Electronic I Class: 1 st stage Exam: Final semester Date: 17/6/2017 Examiner: Dr. Baqer. O. TH. Time: 3 hr. Note: Answer