Nano-technology in a nutshell M.C. Chang Dept of Phys
ENIAC circa 1947 Physical characteristics: 17,468 vacuum tubes; 1,500 relays 60,000 pounds; 16,200 cubic feet 174 kilowatts (233 horsepower) 5,000 addition/sec. (~ same as Intel 4004) 5.25 MJoule/trajectory (~ fire an artillery shell) Future prediction (Popular Mechanics, 1949): 1,500 vacuum tubes; 10 kilowatts 3,000 pounds (~ size of an automobile)
The invention of transistor (1947, Bardeen, Brattain, Shockley) small size less electricity no movable part faster turn-on time 1956
Monolithic device Use a single Si to fabricate all components Include insulator, conductor, rectifier, amplifier… Can it really work? 1959 Kilby (Texas Instrument), after a mass vacation, worked out the first IC -- a simple oscillating circuit (also, Fairchild) Exploding growth of the IC industry 1965 Moore (Fairchild), predicted (based on the data from ’62 to ‘65) that the number of components will double each year 50 at ’65 -> at ’ Noyce and Moore, Intel 1971 Intel’s first microprocessor (4004) 2300 transistors, 100 kHz. computing power as ENIAC
The invention of IC (1959, Kilby and Noyce) Intel 4004 (1971) 2250 transistors Pentium million transistors 2000
A silicon single crystal A silicon wafer
Moore’s law
Cost of Fab Moore’s Second Law $50B $40B 360B $20B $10B $0B Year
Problems fabricating smaller transistors Precision of lithography need UV or e-beam (expansive) Thickness of insulating layer (2 nm, SiO2) need higher dielectric constant Inter-connection problems RC factor: Shrinking of the component by ½, C’=1/2 C, R’= 2R. The same signal delay. Copper wire (solved by IBM 1997 after 25 years of effort)
Micro-Electro-Mechanical Systems (MEMS) + systems-on-a-chip (SOC) = multi-functional, mass production … mems microphone (PC, cellular phone) mems accelerometer (safety bag, Wii, PC, camera, air guitar…) other mems sensors (pressure, heat …) mems oscillator (replaces quartz) optical mems (VSCEL, micro projector) microfluid (printer…) biomems … Cheaper, better, smaller, response time, energy consumption … (lab-on-a-chip)
MEMS mirror Motion sensor DLP micro-projector
From D.J. Yao’s (NTHU) viewgraph
gene chip
Micro-fluid chip
From D.J. Yao’s (NTHU) viewgraph
Top-down approach
Bottom-up approach
Self-organized (or self-assembled) PbSe dots (on PbEuTe)
Carbon nanotube as nanowire Buckminsterfullerene 1996 Buckminster Fuller
STM (Scanning Tunneling Microscope) 1980, Binning and Rohrer 1986
Si(111) surface
Quantum corral made by 48 iron atoms (D. Eigler)
Nano-machine, molecular robot … etc
From sub-micron technology to nano-technology -- problems of this century Emergence of quantum effect Quantum wire Quantum dot Self-assembly device Need better grasp of the fundamental physics of materials How long can we keep enjoying the amazing progress? A powerful computer in turn helps us explore the mystery of nature (high-Tc superconductor, DNA-coding, protein folding, drug design, better airplane… etc)