115C_1_02a_ee_115c_mos_iv

115C_1_02a_ee_115c_mos_iv - EE115C Digital Electronic...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
EE115C Digital Electronic Circuits Lecture 2: MOS Behavior
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
EE115C 2 Metal Oxide Semiconductor Field Effect Transistor Cross Sectional View n+ n+ p+ p substrate Source Drain Body Gate Poly Si SiO 2 SiO 2 Artist’s Rendition…
Background image of page 2
EE115C 3 n+ n+ p+ p substrate Source Drain Body Gate NMOS S G D Analog Representation S G D Digital Representation nMOS Cross-Section and Symbols
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
EE115C 4 p+ p+ n+ n substrate Source Drain Body Gate PMOS S G D Analog Representation D G S Digital Representation pMOS Cross-Section and Symbols
Background image of page 4
EE115C 5 Which is Source, which is Drain ? 1.0 V 1.0 V 0.0 V 1.0 V 1.0 V 0.0 V Current flow Carrier (electron) flow Source Source Drain Drain
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
EE115C 6 Long Channel Vs Short Channel Long channel transistors older technologies, long L’s Short channel transistors new, “deep submicron” technologies, short L’s operation more complicated many 2 nd order effects become pronounced n n p+ p substrate Source Drain Body Gate NMOS L
Background image of page 6
EE115C 7 nMOSFET Basic Operation Long Channel Devices Consider V s =V d and V g is increased Electron are stripped away from atoms in the source and drain region as well as deep in the substrate and attracted to the channel. Simultaneously, holes are pushed away from the surface and into the substrate A conducting channel of electrons is formed n+ p+ p substrate Source Drain Body Gate V s V g V d n+ Carrier (electron) flow Current flow Volts Threshold Voltage, V T Channel a.k.a. Inversion Layer
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
EE115C 8 n + n + p -substrate D S G B x L I D Linear (Triode) Operation Channel is formed The application of a potential between the source and the drain causes current to flow The shape of the channel region changes it becomes more tapered 2 ' 2 DS DS n ox GS T DS n k WV I C V V V L
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 32

115C_1_02a_ee_115c_mos_iv - EE115C Digital Electronic...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online