Extreme ultraviolet lithography : Pushing microchips down to the nanoscale A Wojdyla Center for X-Ray Optics - LBNL December 12 th,

There’s plenty room at the bottom I don't know how to do this on a small scale in a practical way, but I do know that computing machines are very large; they fill rooms. Why can't we make them very small, make them of little wires, little elements – and by little, I mean little. For instance, the wires should be 10 or 100 atoms in diameter, and the circuits should be a few thousand angstroms across. – Richard Feynman (1959) EUV Lithography - All Talk Considered2

Transistors They are electron taps ! Relays & vacuum tubes (“analog”) Solid state transistors (“digital”) EUV Lithography - All Talk Considered3

What is lithography ? (Photo) lithography – “To write in stone” lithos (λίθος) “stone” graphein (γράφειν) “to write” EUV Lithography - All Talk Considered4

How do you make microchips ? (1/2) EUV Lithography - All Talk Considered5 Source : Mack book Inverted microscope

How do you make microchips ? (2/2) 6EUV Lithography - All Talk Considered source : Intel Intel Core x 30 Source : Mack book

How do we make them ? We don’t actually make microchips, but we provide the tools to make them EUV Lithography - All Talk Considered7 For, in order to work iron, a hammer is needed, and the hammer cannot be forthcoming unless it has been made; but, in order to make it, there was need of another hammer and other tools, and so on to infinity – Spinoza A crane, as seen from the CXRO coffee room

Source : ASML Moore’s law “Where a calculator on the ENIAC is equipped with 18,000 vacuum tubes and weighs 30 tons, computers in the future may have only 1,000 vacuum tubes and perhaps weigh 1.5 tons.” - Popular Mechanics (1949) EUV Lithography - All Talk Considered8

Resolution is limited by the wavelength 9EUV Lithography - All Talk Considered

Why would you use Extreme UV ? Current wavelength : 193 nm (excimer) – Go very low in resolution – Use of multi-patterning : lots of masks : lower yield, higher costs New wavelength : 13 nm – 15x smaller wavelength – Materials are available EUV Lithography - All Talk Considered10 xkcd

Challenges for EUV Lithography Source – Cyclotrons, FEL, Z-Pinch, Laser-Produced Plasma – Works in vacuum Optics – Only in reflection – Coating (thin film) Materials – Appropriate polymers 11EUV Lithography - All Talk Considered source : Cymer source : ALS

A sense of scale (1/2) 8 nm feature size – Compare it to the size of a red blood cell : 8 μm – Compare to the width of a DNA strand : 2.3 nm – Compare it to the size of an atom ( 12 C) : 0.2 nm (VdW) EUV Lithography - All Talk Considered12 source : CXRO

EUV Lithography - All Talk Considered13 10 μm

A sense of scale (2/2) 0.1 nm precision (~λ/100) over the size of a mirror 1mm precision over the size of Pacific ocean “Oh man, it’s raining !” 15EUV Lithography - All Talk Considered

Every perturbation is the enemy Pollutants – Vacuum compatibility – Clean room (dust) Vibrations – “calm environments” already shake 1000x too much ! Heat Aluminum’s CTE: 22 μm/m/K ->Metrology is the key “If you can measure it, you can make it.” 16EUV Lithography - All Talk Considered Photon-noise limited experiments (CN Anderson, CXRO) Effects of the dielectric permittivity of air vs. vacuum (A Wojdyla, CXRO) Influence of temperature on the measurements (A Wojdyla, CXRO)

Getting indust-real First industrial tools shipped – 18nm resolution EUV Lithography - All Talk Considered17 ASML NXE:330 Demo tool

Berkeley-Sematech MET 0.5NA To renew the current Micro Exposure Tool (MET) 0.5 Numerical Aperture -> 8 nm resolution EUV Lithography - All Talk Considered18 Sematech members : ASML, IBM, Intel, Texas Instruments,… Berkeley Sematech MET 0.5NA

EUV Lithography - All Talk Considered19

Designing, simulating, prototyping, tolerancing 21 wafer leveling system wavefront sensing optical prototype

Conclusions Next step in semi-conductor industry is EUV lithography It’s not easy, because we have to overcome Nature’s fundamental limits (so do you!) and environmental factors We’ve reached the bottom What’s next in tech ? – 3D chips, graphene transistors, spintronics, quantum computers… EUV Lithography - All Talk Considered22 xkcd

more at cxro.lbl.gov/METcxro.lbl.gov/MET contact : Thank you for your attention

Drawing from Nobel prizes