NCN Nanotechnology 101 Series
Nanoelectronics 101
Mark Lundstrom
Purdue University
Network for Computational Nanotechnology
West Lafayette, IN USA
1)
2)
3)
4)
5)
Introduction
Transistors
CMOS
Integrated Circuits
21C Electronics?
NCN
www.nanohub.org
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1. The importance of transistors (and chips)
supercomputers
iPods
PCs
cell phones
PDAs
2
1. The scale of things
1 meter
(1 billion nm)
1 millimeter
(1 million nm)
1 micrometer
(1 thousand nm)
1 nanometer
•
people
ants
things
dust
cells
molecules
(e.g. DNA)3
1. What is a billion?
A billion seconds ago it was 1959.
A billion minutes ago Jesus was alive.
A billion hours ago our ancestors were living in the StoneAge.
A billion days ago no-one walked on two feet on earth.
4
1. Vacuum tube electronics
Vacuum Tube
ENIAC
(1945, Mauchly and Echkert, U Penn)
http://en.wikipedia.org
Edison effect (Edison, 1883)
cathode rays (Thompson, 1897)
diode (Fleming, ~1900)
triode (De Forest, 1906)
18,000 vacuum tubes
1000 sq. feet of floor space
30 tons
150 KW
~50 vacuum tubes / day
5
2. Transistors
Field-Effect Transistor
Lillienfield, 1925
Heil, 1935
“The transistor was probably the
most important invention of the
20th century,”
Ira Flatow, Transistorized!
www.pbs.org/transistor
6
2. Transistors
transistors
Sony TR-63
6-transistor
shirt pocket radio
1957
http://www.etedeschi.ndirect.co.uk/early.sony.htm
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2. Transistors
symbo
l
switch
amplifier
D
D
D
G
G
G
S
S
S
8
2. Transistors
electron energy
vs. position
S
G
E = -q V
D
source
drain
silicon
SiO2
VD≈ 0V
gate
electrode
gate oxide
SiO2
VD= VDD
channel
9
3. CMOS
G
S
n+ Si
D
S
G
D
p+ Si
p-type silicon
n-MOS: VGS > 0
n-type silicon
p-MOS: VGS < 0
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3. CMOS
VDD
P
VIN
0
VOUT
1
1
VOUT -->
VDD
0
N
VDD
VIN-->
“transfer characteristic”
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3. 2-input CMOS NAND gate
AND
A B C
0 0 0
0 1 0
1 0 0
1 1 1
V
dd
P1
VC
out
A
in1
N1
B
in2
N2
V
V
P2
NAND
A B C
0 0 1
0 1 1
1 0 1
1 1 0
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4. Integrated circuits
integrated circuit
Kilby and Noyce (1958, 1959)
Intel 4004
Hoff and Faggin (1971)
~2200 transistors
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4. Microelectronics
Silicon wafer
(300 mm)
Silicon “chip”
(~ 2 cm x 2 cm)
MPU
Control
logic
ROM
DSP
RAM
analog
Intel
TI cell phone chip
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4. What if a chip were the size of New York City?
MPU
2 cm
20 km
Control
logic
ROM
DSP
RAM
analog
• Transistor gate length would be 4 cm.
• Feature edges would would be specified to the nearest mm.
• There would be 200,000 km of wires (total) on the 8 levels of metal.
From Bob Doering, Texas Instruments, Jan. 2004
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4. Moore’s Law
Gordon E. Moore
Co-founder, Intel Corporation
Copyright © 2005 Intel Corporation.
Electronics, vol. 38,
April 19,1965
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4. Moore’s Law
more transistors per chip means:
higher performance / lower cost
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4. Transistor scaling
35 nm
1.2 nm
~L
Each technology generation:
L→L
2
(device scaling)
A→A 2
Number of transistors per chip doubles
(Moore’s Law)
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4. Nanoelectronics
Working at the length scale of 1-100 nm in order to create
materials, devices, and systems with fundamentally new
properties and functions because of their nanoscale size.
paraphrased from www.nano.gov
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4. Transistor scaling
35 nm
1.2 nm
~L
Each technology generation:
L→L
2
(device scaling)
A→A 2
Number of transistors per chip doubles
(Moore’s Law)
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4. Scaling challenges
~L
1)
2)
3)
4)
5)
low voltage operation
high on-current
low off-current
series resistance
device variability
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4. More than Transistors
Metal 7
Metal 6
Metal 5
Metal 4
Metal 3
Metal 2
Metal 1
transistor
Silicon wafer
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4. The power crises
RR
Power density will increase
Power Density (W/cm2)
10000
ｨ
1000
100
Rocket
Nozzle
Nuclear
Reactor
8086
Hot Plate
10 4004
P6
8008 8085
Pentiumｨ
proc
386
286
486
8080
1
2000
2010
1970
1980
1990
Year
14
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4. Design challenges
1)
2)
3)
4)
5)
power
interconnects
device variability
reliability
complexity
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4. Exponential Growth
1
2
3
4
5
6
7
8
10
11
12
90 nm
1B/chip
2B
4B
8B
16B
32B
64B
128B
256B
512B
1T
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4. Exponential Growth
#1
1 grain of rice
d
#18
small wastebasket
d
d
d
#27
large table
d
d
d
d
d
d
d
d
#37
entire room
#64
1019 grains
surface of Earth
from “Digital Immortal,” by R.W. Lucky, New Republic, Nov. 8. 1999
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4. Exponential Growth
#1
First IC
(1959)
d
d
d
d
d
d
d
d
d
d
d
d
32
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5. Beyone Silicon CMOS: Molecular electronics?
STM
C60 on Si(100) 2x1
TEMPO on p+-Si(100)
Current (nA)
3.0
1.5
Shoulder
0.0
-1.5
NDR
-3.0
-5.0
(Liang and Ghosh)
-2.5
0.0
2.5
Voltage (V)
5.0
Hersam, Datta, Purdue
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5. Beyond Silicon CMOS: Molecular transistors?
S. Datta, A. Ghosh, P. Damle, T. Rakshit
Ghosh, Rakshit, Datta,
Nanoletters 4, 565, 2004
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5. Beyond Silicon CMOS: Carbon nanotube transistors?
Al
Gate
HfO2
S
D
10 nm SiO2
p++ Si
SWNT
D
McEuen et al., IEEE Trans.
Nanotech., 1 , 78, 2002.
G
S
Hongjie Dai group, Stanford
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5. Beyond Silicon CMOS: Nanowire transistors?
Samuelson Group
Lund
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5. Beyond transistors?
Gate
N
D
S
spinFET
qubit
S
spin
+
quantum computing
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5. 21st Century Electronics
1) CMOS devices face serious challenges
leakage, variations, interconnects, …
2) Power dissipation limits device density
not our ability to make devices small
3) CMOS will operate near ultimate limits
no transistor can be fundamentally better
4) CMOS will provide more devices than can be used
increasingly, design will drive progress
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5. 21st Century Electronics
5) New tools, assembly techniques, and understanding
will help push CMOS to its limits
6) Beyond CMOS devices will add functionality to CMOS
non-volatile memory, opto-electronics, sensing….
7) Beyond CMOS technology will address new markets
macroelectronics, bio-medical devices, …
8) Biology may provide inspiration for new technologies
bottom-up assembly, human intelligence
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Nanoelectronics 101
Questions?
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