ECE685 Nanoelectronics – Semiconductor Devices Lecture given by Qiliang Li.

Slides:

Advertisements

Similar presentations

6.1 Transistor Operation 6.2 The Junction FET

Advertisements

ELECTRICAL CONDUCTIVITY

ECE G201: Introductory Material Goal: to give you a quick, intuitive concept of how semiconductors, diodes, BJTs and MOSFETs work –as a review of electronics.

Semiconductor Devices 21

Department of Electronics Semiconductor Devices 25 Atsufumi Hirohata 11:00 Monday, 1/December/2014 (P/L 005)

Semiconductor Device Physics

Physics of Semiconductor Devices. Formation of PN - Junction When a P-type Semiconductor is joined together with an N-type Semiconductor a PN junction.

ECE 4339: Physical Principles of Solid State Devices

Bohr quantized the atom… An atom has a set of energy levels Some (but not all) occupied by electrons Not really dealing with isolated atoms, but 3D solids.

Integrated Circuit Devices

Fabrication of p-n junction in Si Silicon wafer [1-0-0] Type: N Dopant: P Resistivity: Ω-cm Thickness: µm.

Department of Electronics Introductory Nanotechnology ~ Basic Condensed Matter Physics ~ Atsufumi Hirohata.

Spring 2007EE130 Lecture 34, Slide 1 Lecture #34 OUTLINE The MOS Capacitor: MOS non-idealities (cont.) V T adjustment Reading: Chapter 18.3.

Section 12: Intro to Devices

Lecture #3 OUTLINE Band gap energy Density of states Doping Read: Chapter 2 (Section 2.3)

Spring 2007EE130 Lecture 30, Slide 1 Lecture #30 OUTLINE The MOS Capacitor Electrostatics Reading: Chapter 16.3.

9/24/2004EE 42 fall 2004 lecture 111 Lecture #11 Metals, insulators and Semiconductors, Diodes Reading: Malvino chapter 2 (semiconductors)

EE580 – Solar Cells Todd J. Kaiser Lecture 05 P-N Junction 1Montana State University: Solar Cells Lecture 5: P-N Junction.

Unit-II Physics of Semiconductor Devices. Formation of PN Junction and working of PN junction. Energy Diagram of PN Diode, I-V Characteristics of PN Junction,

Lecture 2 OUTLINE Semiconductor Fundamentals (cont’d) – Energy band model – Band gap energy – Density of states – Doping Reading: Pierret , 3.1.5;

Lecture 3. Intrinsic Semiconductor When a bond breaks, an electron and a hole are produced: n 0 = p 0 (electron & hole concentration) Also:n 0 p 0 = n.

MOS Capacitors ECE Some Classes of Field Effect Transistors Metal-Oxide-Semiconductor Field Effect Transistor ▫ MOSFET, which will be the type that.

Lecture 2 OUTLINE Important quantities Semiconductor Fundamentals (cont’d) – Energy band model – Band gap energy – Density of states – Doping Reading:

Semiconductor Devices 22

EE415 VLSI Design The Devices: Diode [Adapted from Rabaey’s Digital Integrated Circuits, ©2002, J. Rabaey et al.]

Semiconductor Devices 27

The Devices: Diode.

ECE 431 Digital Circuit Design Chapter 3 MOS Transistor (MOSFET) (slides 2: key Notes) Lecture given by Qiliang Li 1.

Depletion Region ECE Depletion Region As electrons diffuse from the n region into the p region and holes diffuse from the p region into the n region,

Higher Physics Semiconductor Diodes. Light Emitting Diode 1  An LED is a forward biased diode  When a current flows, electron-hole pairs combine at.

Drift and Diffusion Current

Kristin Ackerson, Virginia Tech EE Spring The diode is the simplest and most fundamental nonlinear circuit element. Just like resistor, it has.

Taklimat UniMAP Universiti Malaysia Perlis WAFER FABRICATION Hasnizah Aris, 2008 Lecture 2 Semiconductor Basic.

LW4 Lecture Week 4-1 Heterojunctions Fabrication and characterization of p-n junctions 1.

Chapter Intrinsic: -- case for pure Si -- # electrons = # holes (n = p) Extrinsic: -- electrical behavior is determined by presence of impurities.

ENE 311 Lecture 9.

Penn ESE370 Fall DeHon 1 ESE370: Circuit-Level Modeling, Design, and Optimization for Digital Systems Day 8: September 24, 2010 MOS Model.

Integrated Circuit Devices Professor Ali Javey Summer 2009 Semiconductor Fundamentals.

© 2012 Eric Pop, UIUCECE 340: Semiconductor Electronics ECE 340 Lecture 30 Metal-Semiconductor Contacts Real semiconductor devices and ICs always contain.

SILICON DETECTORS PART I Characteristics on semiconductors.

ECE 4339 L. Trombetta ECE 4339: Physical Principles of Solid State Devices Len Trombetta Summer 2007 Chapters 16-17: MOS Introduction and MOSFET Basics.

Norhayati Soin 06 KEEE 4426 WEEK 3/1 9/01/2006 KEEE 4426 VLSI WEEK 3 CHAPTER 1 MOS Capacitors (PART 1) CHAPTER 1.

Lecture 18 OUTLINE The MOS Capacitor (cont’d) – Effect of oxide charges – Poly-Si gate depletion effect – V T adjustment Reading: Pierret ; Hu.

1 Detectors RIT Course Number Lecture N: Lecture Title.

Lecture 18 OUTLINE The MOS Capacitor (cont’d) – Effect of oxide charges – V T adjustment – Poly-Si gate depletion effect Reading: Pierret ; Hu.

Conductors – many electrons free to move

MOS Device Physics and Designs Chap. 3 Instructor: Pei-Wen Li Dept. of E. E. NCU 1 Chap 3. P-N junction  P-N junction Formation  Step PN Junction  Fermi.

NEEP 541 Ionization in Semiconductors Fall 2002 Jake Blanchard.

Many solids conduct electricity

1 Semiconductor Devices  Metal-semiconductor junction  Rectifier (Schottky contact or Schottky barrier)  Ohmic contact  p – n rectifier  Zener diode.

CHAPTER 4: P-N JUNCTION Part I.

Integrated Circuit Devices

President UniversityErwin SitompulSDP 2/1 Dr.-Ing. Erwin Sitompul President University Lecture 2 Semiconductor Device Physics

Side ViewTop View Beginning from a silicon wafer.

CSE251 CSE251 Lecture 2 and 5. Carrier Transport 2 The net flow of electrons and holes generate currents. The flow of ”holes” within a solid–state material.

월 19 일 중간고사 1: 6:00 – 8:00 pm. 2 3 Hybridization of s- and p-states Two s+p bands, lower filled higher empty for Ge, Si Group IV 8.1 Band Structure.

P – n junction Prof.Dr.Beşire GÖNÜL.  the basic element of all bipolar devices. >photodiode, light sensitive diode, >LED- ligth emitting diode, >laser.

EE130/230A Discussion 10 Peng Zheng.

A semiconductor material cannot be viewed as a collection of non interacting atoms, each with its own individual energy levels. Because of the proximity.

Review of Semiconductor Devices

Band Theory of Electronic Structure in Solids

Intro to Semiconductors and p-n junction devices

Physics of Semiconductor Devices

LTFY – Physics and Engineering

Lecture 2 OUTLINE Important quantities

Introduction to Semiconductors

Read: Chapter 2 (Section 2.3)

EECS143 Microfabrication Technology

Chapter 1 – Semiconductor Devices – Part 2

Presentation transcript:

ECE685 Nanoelectronics – Semiconductor Devices Lecture given by Qiliang Li

Unit cell of silicon crystal is cubic. Each Si atom has 4 nearest neighbors. Silicon Structure

AsB Dopants, Electrons and holes

N-type P-type Relationship between Resistivity and Dopant Density  = 1/  DOPANT DENSITY cm -3 RESISTIVITY (  cm)

GaAs, III-V Compound Semiconductors, and Their Dopants As Ga  GaAs has the same crystal structure as Si.  GaAs, GaP, GaN are III-V compound semiconductors, important for optoelectronics.  Wich group of elements are candidates for donors? acceptors? GaAs Ga

Energy Band Model  Energy states of Si atom (a) expand into energy bands of Si crystal (b).  The lower bands are filled and higher bands are empty in a semiconductor.  The highest filled band is thevalence band.  The lowest empty band is theconduction band.

Energy Band Diagram Conduction band E c E v E g Band gap Valence band   Energy band diagram shows the bottom edge of conduction band, E c, and top edge of valence band, E v.  E c and E v are separated by the band gap energy, E g.

Donor and Acceptor in the Band Model Conduction Band E c E v Valence Band Donor Level Acceptor Level E d E a Donor ionization energy Acceptor ionization energy Ionization energy of selected donors and acceptors in silicon

Device Fabrication Oxidation Lithography & Etching Ion Implantation Annealing & Diffusion

Side ViewTop View Beginning from a silicon wafer

Side ViewTop View Thermal Oxidation

Side ViewTop View Spin-on Photo Resist (PR)

Side ViewTop View Alignment, UV Expose and Develop Photo Resist (PR)

Side ViewTop View Oxide Etched

Side ViewTop View Remove Photo Resist (PR)

Side ViewTop View Doping (implantation or diffusion)

Side ViewTop View Grow Field Oxide (wet/dry) and dopant diffusion

Side ViewTop View Spin-on Photo Resist (PR)

Side ViewTop View Alignment, UV Expose and Develop Photo Resist (PR)

Side ViewTop View Oxide Etched

Side ViewTop View Remove Photo Resist (PR)

Side ViewTop View Grow Gate Oxide (dry)

Side ViewTop View Spin-on Photo Resist (PR)

Side ViewTop View Alignment, UV Expose and Develop Photo Resist (PR)

Side ViewTop View Field Oxide Etched

Side ViewTop View Field Oxide Etched

Side ViewTop View Metal (e.g., Aluminum) deposition

Side ViewTop View Spin-on Photo Resist (PR)

Side ViewTop View Alignment, UV Expose and Develop Photo Resist (PR)

Side ViewTop View Aluminum Etched

Side ViewTop View Remove Photo Resist (PR), annealing - complete

PN junction is present in perhaps every semiconductor device. N P V I – + PN Junction V I Reverse bias Forward bias Donor ions N-type P-type

Energy Band Diagram of a PN Junction A depletion layer exists at the PN junction where n  0 and p  0. E f is constant at equilibrium E c and E v are smooth, the exact shape to be determined. E c and E v are known relative to E f N-region P-region (a) EfEf (c) EcEc EvEv EfEf (b) EcEc EfEf EvEv EvEv EcEc (d) Depletion layer Neutral P-region Neutral N-region EcEc EvEv EfEf

Light emitting diodes (LEDs) LEDs are made of compound semiconductors such as InP and GaN. Light is emitted when electron and hole undergo radiative recombination. EcEc EvEv Radiative recombination Non-radiative recombination through traps

LED Materials and Structure

Common LEDs AlInGaP Quantun Well

V I Reverse bias Forward bias V = 0 Forward biased Reverse biased Schottky Diodes

MOS: Metal-Oxide-Semiconductor SiO 2 metal gate Si body VgVg gate P-body N+ N+ MOS capacitor MOS transistor VgVg SiO 2 N+ N+

Surface Accumulation Gauss’s Law V g <V t

Surface Depletion ( ) g V> V fb SiO 2 gate P-Si body V depletion layer charge,Q dep

Threshold Condition and Threshold Voltage Threshold (of inversion): n s = N a, or (E c –E f ) surface = (E f – E v ) bulk, or  A=B, and C = D E c, E f M O S E v E f E i E c A B C = q   E v D qV g = t  st

Threshold Voltage + for P-body, – for N-body

Strong Inversion–Beyond Threshold V g > V t

Basic MOSFET structure and IV characteristics + +