Lecture 20 OUTLINE The MOSFET (cont’d)

Slides:

Advertisements

Similar presentations

Lecture Metal-Oxide-Semiconductor (MOS) Field-Effect Transistors (FET) MOSFET Introduction 1.

Advertisements

EE130/230A Discussion 12 Peng Zheng 1. Velocity Saturation Velocity saturation limits I Dsat in sub-micron MOSFETS Simple model: E sat is the electric.

Lecture #16 OUTLINE Diode analysis and applications continued

The metal-oxide field-effect transistor (MOSFET)

Week 8b OUTLINE Using pn-diodes to isolate transistors in an IC

Spring 2007EE130 Lecture 36, Slide 1 Lecture #36 ANNOUNCEMENTS Updated information for Term Project was posted on 4/14 Reminder: Coffee Hour today at ~4PM!

Spring 2007EE130 Lecture 38, Slide 1 Lecture #38 OUTLINE The MOSFET: Bulk-charge theory Body effect parameter Channel length modulation parameter PMOSFET.

EE105 Fall 2007Lecture 16, Slide 1Prof. Liu, UC Berkeley Lecture 16 OUTLINE MOS capacitor (cont’d) – Effect of channel-to-body bias – Small-signal capacitance.

Lecture 19 OUTLINE The MOSFET: Structure and operation

Semiconductor Devices III Physics 355. Transistors in CPUs Moore’s Law (1965): the number of components in an integrated circuit will double every year;

EE130/230A Discussion 11 Peng Zheng.

Norhayati Soin 06 KEEE 4426 WEEK 7/1 6/02/2006 CHAPTER 2 WEEK 7 CHAPTER 2 MOSFETS I-V CHARACTERISTICS CHAPTER 2.

Lecture 9 OUTLINE pn Junction Diodes – Electrostatics (step junction) Reading: Pierret 5; Hu

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

MOSFET Current Voltage Characteristics Consider the cross-sectional view of an n-channel MOSFET operating in linear mode (picture below) We assume the.

EE130/230A Discussion 10 Peng Zheng.

Damu, 2008EGE535 Fall 08, Lecture 21 EGE535 Low Power VLSI Design Lecture #2 MOSFET Basics.

EE314 IBM/Motorola Power PC620 IBM Power PC 601 Motorola MC68020 Field Effect Transistors.

Chapter 6 The Field Effect Transistor

Lecture 18 OUTLINE The MOS Capacitor (cont’d) Effect of oxide charges

Field Effect Transistors

Chapter 2 MOS Transistors.

MOS Field-Effect Transistors (MOSFETs)

Other Transistor Topologies

Lecture 25 OUTLINE The Bipolar Junction Transistor Introduction

Recall Last Lecture Common collector Voltage gain and Current gain

Lecture 10 OUTLINE pn Junction Diodes (cont’d)

Lecture 21 OUTLINE The MOSFET (cont’d) P-channel MOSFET

Lecture 20 OUTLINE The MOSFET (cont’d) Qualitative theory

Lecture 22 OUTLINE The MOSFET (cont’d) MOSFET scaling

Intro to Semiconductors and p-n junction devices

3: CMOS Transistor Theory

Lecture 17 OUTLINE The MOS Capacitor (cont’d) Small-signal capacitance

VLSI System Design Lect. 2.1 CMOS Transistor Theory

Lecture 22 OUTLINE The MOSFET (cont’d) Velocity saturation

Lecture 16 ANNOUNCEMENTS OUTLINE MOS capacitor (cont’d)

Lecture 19 OUTLINE The MOSFET: Structure and operation

Notes on Diodes 1. Diode saturation current:

Week 9a OUTLINE MOSFET ID vs. VGS characteristic

منبع: & کتابMICROELECTRONIC CIRCUITS 5/e Sedra/Smith

Reading: Finish Chapter 17,

Optional Reading: Pierret 4; Hu 3

Lecture 17 OUTLINE The MOS Capacitor (cont’d) Small-signal capacitance

MOSFETs - An Introduction

Lecture 21 OUTLINE The MOSFET (cont’d) P-channel MOSFET

Lecture 21 OUTLINE The MOSFET (cont’d) P-channel MOSFET

Lecture 25 OUTLINE The Bipolar Junction Transistor Introduction

Week 9a OUTLINE MOSFET ID vs. VGS characteristic

Lecture 21 OUTLINE The MOSFET (cont’d) P-channel MOSFET

Lecture 16 OUTLINE The MOS Capacitor (cont’d) Electrostatics

Lecture #17 (cont’d from #16)

Lecture 10 OUTLINE pn Junction Diodes (cont’d)

Lecture 9 OUTLINE pn Junction Diodes Electrostatics (step junction)

Lecture 3: CMOS Transistor Theory

Lecture 20 OUTLINE The MOSFET (cont’d) Qualitative theory

Lecture 16 OUTLINE The MOS Capacitor (cont’d) Electrostatics

CP-406 VLSI System Design CMOS Transistor Theory

Lecture 12 OUTLINE pn Junction Diodes (cont’d)

Lecture 22 OUTLINE The MOSFET (cont’d) MOSFET scaling

Lecture 22 OUTLINE The MOSFET (cont’d) Velocity saturation

Lecture #15 OUTLINE Diode analysis and applications continued

Lecture 3: CMOS Transistor Theory

Lecture 20 OUTLINE The MOSFET (cont’d)

Lecture 12 OUTLINE pn Junction Diodes (cont’d)

Lecture 3: CMOS Transistor Theory

Lecture 16 OUTLINE The MOS Capacitor (cont’d) Electrostatics

Other Transistor Topologies

Lecture #16 OUTLINE MOSFET ID vs. VGS characteristic

Lecture 16 OUTLINE The MOS Capacitor (cont’d) Electrostatics

Other Transistor Topologies

Presentation transcript:

Lecture 20 OUTLINE The MOSFET (cont’d) Long-channel I-V characteristics Reading: Pierret 17.2; Hu 6.6

Derivation of NMOSFET I-V VD > VS Current in the channel flows by drift Channel voltage VC(y) varies continuously between the source and the drain Channel inversion charge density W EE130/230A Fall 2013 Lecture 20, Slide 2 R. F. Pierret, Semiconductor Device Fundamentals, Figs. 17.6

1st-Order Approximation If we neglect the variation of Qdep with y, then where VT is defined to be the threshold voltage at the source end: The inversion charge density is then EE130/230A Fall 2013 Lecture 20, Slide 3

NMOSFET Current (1st-order approx.) Consider an incremental length dy of the channel. The voltage drop across this region is in the linear region EE130/230A Fall 2013 Lecture 20, Slide 4

Saturation Current, IDsat (1st-order approximation) C. C. Hu, Modern Semiconductor Devices for Integrated Circuits, Figure 6-16 IDS saturates when VD reaches VG-VT  Set VD = VG-VT in the equation for ID EE130/230A Fall 2013 Lecture 20, Slide 5

Problem with “Square Law Theory” Ignores variation in depletion width with distance y: where EE130/230A Fall 2013 Lecture 20, Slide 6

Modified (Bulk-Charge) I-V Model In linear region: In saturation region: EE130/230A Fall 2013 Lecture 20, Slide 7

MOSFET Threshold Voltage, VT The expression that was previously derived for VT is the gate voltage referenced to the body voltage that is required reach the threshold condition: Usually, the terminal voltages for a MOSFET are all referenced to the source voltage. In this case, and the equations for IDS are EE130/230A Fall 2013 Lecture 20, Slide 8

The Body Effect Note that VT is a function of VSB: where g is the body effect parameter When the source-body pn junction is reverse-biased, |VT| is increased. Usually, we want to minimize g so that IDsat will be the same for all transistors in a circuit. EE130/230A Fall 2013 Lecture 20, Slide 9

MOSFET VT Measurement VT can be determined by plotting IDS vs. VGS, using a low value of VDS IDS VGS EE130/230A Fall 2013 Lecture 20, Slide 10

Long-Channel MOSFET I-V Summary In the ON state (VGS>VT for NMOS; VGS<VT for PMOS), the inversion layer at the semiconductor surface forms a “channel” for current to flow by carrier drift from source to drain In the linear region of operation (VDS < (VGSVT)/m): In the saturation region of operation (VDS > (VGSVT)/m): EE130/230A Fall 2013 Lecture 20, Slide 11