NCN Nanotechnology 101 Series Nanoelectronics 101

Mark Lundstrom Purdue University Network for Computational Nanotechnology West Lafayette, IN USA

1) Introduction 2) Transistors 3) CMOS 4) Integrated Circuits 5) 21C Electronics? NCN www.nanohub.org 1 1. The importance of transistors (and chips)

supercomputers iPods

PCs

cell phones

PDAs 2 1. The scale of things

1 meter 1 millimeter 1 micrometer 1 nanometer (1 billion nm) (1 million nm) (1 thousand nm)

•

people ants cells molecules things dust (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) 18,000 vacuum tubes cathode rays (Thompson, 1897) 1000 sq. feet of floor space diode (Fleming, ~1900) 30 tons triode (De Forest, 1906) 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

Sony TR-63 transistors 6-transistor shirt pocket radio 1957

http://www.etedeschi.ndirect.co.uk/early.sony.htm

7 2. Transistors

amplifier symbol switch

D D

D

G G G S

S S

8 2. Transistors

electron energy vs. position E = -q V

SDG

VD≈ 0V

source drain 2

silicon SiO gate electrode VD= VDD

gate oxide channel

SiO2 9 3. CMOS

G G S D S D n+ Si p+ Si

p-type silicon n-type silicon

n-MOS: VGS > 0 p-MOS: VGS < 0

10 3. CMOS

VDD

VDD P --> 0 V 1

OUT OUT

VIN V 1 0 N VDD VIN-->

“transfer characteristic”

11 3. 2-input CMOS NAND gate

V AND dd ABC 000

010 P1 P2 100 V 111 outC NAND VA N1 in1 ABC 001 011 VB N2 in2 101 110

12 4. Integrated circuits

integrated circuit Intel 4004

Kilby and Noyce (1958, 1959) Hoff and Faggin (1971)

~2200 transistors

13 4. Microelectronics

Silicon wafer (300 mm)

Silicon “chip” (~ 2 cm x 2 cm)

MPU ROM

DSP Control logic RAM analog

Intel TI cell phone chip 14 4. What if a chip were the size of New York City?

MPU ROM 20 km 2 cm DSP Control logic 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. 15 From Bob Doering, Texas Instruments, Jan. 2004 4. Moore’s Law

Gordon E. Moore Co-founder, Intel Corporation

Electronics, vol. 38, Copyright © 2005 Intel Corporation. April 19,1965

16 4. Moore’s Law

more transistors per chip means:

higher performance / lower cost 17 4. Transistor scaling

35 nm

1.2 nm ~ L

Each technology generation: (device scaling) L → L 2 A → A 2

Number of transistors per chip doubles (Moore’s Law)

18 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

19 4. Transistor scaling

35 nm

1.2 nm ~ L

Each technology generation: (device scaling) L → L 2 A → A 2

Number of transistors per chip doubles (Moore’s Law)

20 4. Scaling challenges

~ L

1) low voltage operation 2) high on-current 3) low off-current 4) series resistance 5) device variability

21 4. More than Transistors

Metal 7

Metal 6

Metal 5

Metal 4

Metal 3

Metal 2

Metal 1 transistor

Silicon wafer

22 4. The power crises

RR Power density will increase 10000 Rocket Nozzle 1000 Nuclear Reactor 100

8086 10 4004 Hot Plate P6 8008 8085 386 Pentiumｨ proc 286 486

Power Density (W/cm2) Power Density 8080 1 1970 1980 1990 2000 2010 Year

ｨ 14 23 4. Design challenges

1) power 2) interconnects 3) device variability 4) reliability 5) complexity

24 4. Exponential Growth

1 90 nm 1B/chip 2 2B 3 4B 4 8B 5 16B 6 32B 7 64B 8 128B 10 256B 11 512B 12 1T 25 4. Exponential Growth

#1 1 grain of rice d d d d #18 d d d d small wastebasket #37 d d d d entire room

#27 large table #64 1019 grains surface of Earth

from “Digital Immortal,” by R.W. Lucky, New Republic, Nov. 8. 1999 26 4. Exponential Growth

#1 First IC (1959) d d d d d d d d d d d 32d

27 5. Beyone Silicon CMOS: Molecular electronics?

STM

C60 on Si(100) 2x1

TEMPO on p+-Si(100) 3.0

1.5 Shoulder

0.0

-1.5 Current (nA) NDR -3.0

-5.0 -2.5 0.0 2.5 5.0 Voltage (V)

(Liang and Ghosh) Hersam, Datta, Purdue 28 5. Beyond Silicon CMOS: Molecular transistors?

S. Datta, A. Ghosh, P. Damle, T. Rakshit Ghosh, Rakshit, Datta, Nanoletters 4, 565, 2004 29 5. Beyond Silicon CMOS: Carbon nanotube transistors?

Al Gate

HfO2 D S

10 nm SiO2

p++ Si

SWNT

DSG

Hongjie Dai group, Stanford McEuen et al., IEEE Trans. Nanotech., 1 , 78, 2002. 30 5. Beyond Silicon CMOS: Nanowire transistors?

Samuelson Group

Lund 31 5. Beyond transistors?

Gate N S D

spinFET

qubit S +

spin quantum computing 32 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

33 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

34 Nanoelectronics 101

Questions?

35