ME 381R Lecture 13-14

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ME 381R Lecture 13-14 Semiconductor Devices and
Thermal Issues
Dr. Li Shi Department of Mechanical Engineering
The University of Texas at Austin Austin, TX
78712 www.me.utexas.edu/lishi lishi_at_mail.utexas.
edu
Reading 1-7-1 Ch. 7 in Tien et al.
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p-n Junction w/o Bias
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Biased p-n Junction
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Metal-Oxide-Semiconductor (MOS) Capacitor
? Electron Affinity ? Work Function
Energy Band Diagram before making contact
n-type
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MOS Capacitor W/O Bias (Special Case ?M ?S)
Energy Band Diagram after making contact
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Accumulation and Depletion of Majority Carriers
Block Charge Diagram
Vi
Very thin
eVG
VS
VG
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Inversion Layer C majority carrier gtC minority
carrier
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Metal-Oxide-Semiconductor Field-Effect Transistor
(MOSFET)
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Ideal MOSFET
VGgt0
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Pinch-Off IV
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Thermal Circuit
Particle transport theory
Fouriers law of heat conduction
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Joule Heating inHigh-Field Devices
Localized heat generation near the pinch-off point
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Thermometry of Nanoelectronics
Scanning Thermal Microscope
Atomic Force Microscope (AFM) Thermal
Probe
Laser
Deflection Sensing
Cantilever
Temperature Sensor
Sample
X-Y-Z Actuator
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Microfabricated Probes
Pt Line
Tip
Pt-Cr Junction
Laser Reflector
SiNx Cantilever
Cr Line
Shi, Kwon, Miner, Majumdar, J. MicroElectroMechani
cal Sys., 10, p. 370 (2001)
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Self Heating Effect on I-V
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Optical Phonon Emission at High Field
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Heat Transfer Path
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Governing Equations for Electro-Thermal
Simulation of Devices
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Example
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Computation Scheme
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Results
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Electric Field
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Electron Temperature
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Phonon Temperature