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 1 1. The importance of transistors (and chips) QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. supercomputers iPods PCs QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. cell phones PDAs 2 1. The scale of things 1 meter (1 billion nm) 1 millimeter (1 million nm) 1 micrometer (1 thousand nm) people ants things dust cells ros se a .er rpm dna utc oce ™ ip d ) em sih de iTk t e ss ciu es erp Q ot mo de cn de U en ( F era FIT • 1 nanometer 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) QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 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 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Bardeen, Schockley, and Brattain, 1947 “The transistor was probably the most important invention of the 20th century,” Ira Flatow, Transistorized! www.pbs.org/transistor QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 6 2. Transistors transistors QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Sony TR-63 6-transistor shirt pocket radio 1957 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. http://www.etedeschi.ndirect.co.uk/early.sony.htm 7 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 10 3. CMOS VDD P VIN 0 VOUT 1 1 VOUT --> VDD 0 N VDD VIN--> “transfer characteristic” 11 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 12 4. Integrated circuits integrated circuit QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Kilby and Noyce (1958, 1959) Intel 4004 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Hoff and Faggin (1971) ~2200 transistors 13 4. Microelectronics Silicon wafer (300 mm) Silicon “chip” (~ 2 cm x 2 cm) MPU Control logic QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Intel ROM DSP RAM analog TI cell phone chip 14 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 15 4. Moore’s Law Gordon E. Moore Co-founder, Intel Corporation QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Copyright © 2005 Intel Corporation. Electronics, vol. 38, 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: L→L 2 (device scaling) 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. Scaling challenges ~L 1) 2) 3) 4) 5) low voltage operation high on-current low off-current series resistance device variability 20 4. More than Transistors Metal 7 Metal 6 Metal 5 Metal 4 Metal 3 Metal 2 Metal 1 transistor Silicon wafer 21 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 22 4. Design challenges 1) 2) 3) 4) 5) power interconnects device variability reliability complexity 23 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 24 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 25 4. Exponential Growth #1 First IC (1959) d d d d d d d d d d d d 32 26 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 27 5. Beyond Silicon CMOS: Molecular transistors? S. Datta, A. Ghosh, P. Damle, T. Rakshit Ghosh, Rakshit, Datta, Nanoletters 4, 565, 2004 28 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 29 5. Beyond Silicon CMOS: Nanowire transistors? QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Samuelson Group Lund 30 5. Beyond transistors? Gate N D S spinFET QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. qubit S spin + quantum computing 31 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 32 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 33 Nanoelectronics 101 Questions? 34