Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Metal-Insulator Electronics for 60 GHz and Beyond] Date Submitted: [7 March, 2006] Source: [Moddel, Garret] Company [Phiar Corp.] Address [2555 55th St., Bldg. D #104, Boulder CO, 80301] Voice:[(303) 443-0373], FAX: [], E-Mail:[adam@phiar.com] Re: [] Abstract: [Metal-insulator devices have been developed for 60 GHz and beyond. The devices can be integrated into a CMOS process, and provide a low-cost, integratable technology for wireless applications] Purpose: [Making the TG3c group aware of a non-semiconductor approach to mm-wave PHYs.] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. Metal-Insulator Electronics:Low Cost, CMOS-Compatible Devices for 60 GHz and BeyondIEEE 802.15.TG3c 6th Meeting – March 7, 2006 • Garret Moddel • Chairman & CTO, Phiar Corp. • Professor, University of Colorado

3. Metal-Insulator Diode Detector Top View Side View antenna top metal load insulator incident radiation base metal MIM diode a “crystal radio” for ultra-high frequency electromagnetic waves

4. Outline • Metal-insulator technology • Diodes • Double-insulator diode • Detectors & modulators • Transistors • Applications

5. Metal-Insulator-Metal Diode Rectification • Carrier signal alternates polarity across diode • Electrons tunnel preferentially in one direction due to difference in metal barrier heights • Tunneling is extremely fast (~1 femtosecond) – allows for ultra-high carrier frequencies (> 1 terahertz)

6. Current-Voltage Curves Slope determines resistance Current Matching antenna • Diode resistance should match antenna resistance - which is usually low Sensitivity • Detector responsivity (sensitivity) increases with nonlinearity Double-insulator diode • Large slope - matches antenna • Large nonlinearity - high responsivity MIM diode Voltage Nonlinearity (curvature) Large slope (low resistance) Current MI-IM diode Voltage Large nonlinearity

7. 15 Zero bias: Quantum wells 14 Energy (eV) 13 M2 M1 I2 I1 12 11 anode cathode 10 9 10-30 100 Reverse bias: Forward bias: Electron Transmission e- e- anode cathode anode cathode Double-Insulator Tunneling Diode • When Fermi level reaches quantum well, electrons get a “free ride” • Result: sharp turn-on

8. Measured Diode I(V) Curves • Reproducible • Steep slope • Sharp “knee” • Low OFF current Image Credit: Phiar. Contact pad design: Motorola.

9. Detectors & Modulators • Diode + antenna

10. 200 GHz Testing 200 GHz Mixing Response* • Removes effects from other physical mechanisms • Results assure device truly operating at 200 GHz -75 -85 -95 -105 dBm -115 measured -125 delta-f output theoretical -135 delta-f output -145 -0.25 -0.15 -0.05 0.05 0.15 0.25 bias (V) * Testing performed at Harvard Smithsonian

11. 1 THz Testing THz detector 1 THz Pulsed Laser Response* * Testing performed at UCSB

12. Diode: Why It’s So Fast • Short carrier transit time – because quantum mechanical tunneling • Low lead parasitic resistance – because all metal & no semiconductor bulk to add high resistance • Low RC time constant • Low capacitance (C) due to small diode area • Low resistance (R) due to • Double insulator large nonlinearity • Choice of materials to produce low barrier • Note: low resistance also improves impedance match of diode to antenna – improves efficiency

13. 200 GHz 20 GHz Antenna Innovation: Edge-Fed Antenna for Ultra-high Frequencies • Separates carrier and signal frequencies • Improves antenna efficiency • Improves matching to diode • Color code for this simulation: • Blue = low power • yellow/green = high power 200 GHz carrier is received by antenna and channeled to diode region, where it is rectified 20 GHz rectified signal is channeled out the leads

14. Ex Vbias overlap antenna Ey MIIM waveguide z y x Ez top metal tunnel junction plasmon wave bottom metal Traveling Wave Detector • Improves: • Efficiency • Impedance matching to antenna • RC time constant

15. Comparison: THz Detectors • Fast  useful for heterodyne & direct detection • Sensitive  high responsivity & low noise • Integratable  thin film deposited at low temp on virtually any substrate (plastic, glass, CMOS, GaAs, etc.)

16. Antenna Transmission & Reflection: Towards Modulation 1 0 0 % 2 ] [ Z Z - 9 0 % L O A D o R = Z Z absorbed power + 8 0 % L O A D o 7 0 % 6 0 % Reflected & Absorbed Power Z = Z 5 0 % d i o d e o 4 0 % 3 0 % reflected power 2 0 % 1 0 % 0 % 0 1 0 0 0 2 0 0 0 3 0 0 0 4 0 0 0 D i o d e R e s i s t a n c e ( o h m s )

17. Modulator Demonstration

18. Metal-Insulator Tunneling Transistor narrow emitter stripe double-I emitter oxides B base metal C collector oxide E low  substrate

19. MIIMIM Tunneling Hot Electron Transistor Predicted Performance hot electron base collector emitter emitter metal emitter insulator (double-I) ~ 6 nm ~ 10 nm base metal ~ 10 nm collector insulator collector metal

20. Energy Spread of Injected Electrons MIMIM J(E) Problem: Energy spread reduces gain 0.2 • Low energy electrons clipped by barrier • High energy electrons scatter hot electron current distribution EF 0.0 Energy (eV) MIIMIM Solution: MIIM emitter 0.4 • (chart at left) • Narrower hot electron distribution • Lower energy hot electron distribution J(E) 0.2 EF 0.0 4 8 12 16 20 Distance (nm) 0

21. Exceeding Other Transistor Technologies Phiar 3 THz SiGe HBT 410 Yellow: frequencies where engineering challenges remain InP HBT 400 InP HEMT 300 Technologies projected to hit “Brick Wall” by 2010 – further progress not expected. GaAs MHEMT 275 GaAs PHEMT 250 GaN HEMT 150 0 500 1000 1500 2000 2500 3000 Maximum transistor frequencies: fmax (GHz) Source: TheInternational Technology Roadmap for Semiconductors: 2005; Phiar projections.

22. Transistor: Why It’s So Fast • Advantages over semiconductor transistors: • Transit time • Base & lead resistance • Integratable, etc. emitter oxides emitter base metal collector base collector oxide low  substrate

23. The Basic Building Block: Metal-Insulator High-Frequency Transceiver Thin film metal-insulator transmitter and receiver • Stand-alone device or • Integrated onto chip - - - • Wireline or • Wireless High speed semiconductor signal conditioning circuitry Metal-insulator detectors have been demonstrated on CMOS chips

24. Features of Metal-Insulator Technology • Ultra-high-speed  up to THz diodes & transistors • Thin film  low-cost, large-area, integratable on CMOS, plastic, etc. • No exotic materials or processes  compatible with CMOS fab • High efficiency  practical • Low voltage  compatible with CMOS • Low cost • One technology does it all: diodes, transistors, antennas, arrays…

25. Outline • Metal-insulator technology • Diodes • Double-insulator diode • Detectors & modulators • Transistors • Applications

26. Personal Area Networks:the 10 meter opportunity

27. Intra-box:the 10 cm opportunity • Removes slow copper • Provides design flexibility CPU GPU

28. 1 Gb/s Ethernet 10 Mb/s Ethernet 802.11g Wireline 802.11b “Nomadic” MIMO 9600 b/s Modem Wireless GSM 30 Years of Bandwidth Source: IEEE Spectrum, “Edholm’s Law of Bandwidth: Telecommunications data rates are as predictable as Moore’s Law,” July 2004.

29. Beyond Copper MIIM Technology Wireline UWB at 0.48 & 1.2 Gb/s Nomadic “Pre-N” 802.11 Cellular Source: IEEE Spectrum, “Edholm’s Law of Bandwidth,” July 2004; Phiar estimates.

30. RF-on-Flex Applications • Low-cost radar (e.g., automotive) • Lightweight satellite uplinks/downlinks • Free-space data links, communications • RF ID tags and smart tags • Completely integrated phased arrays on flex • Very large aperture radar Metal-insulator diodes have been demonstrated on plastic substrates

31. Terahertz Radiation • T-rays (terahertz radiation) technology: One of “10 Emerging Technologies That Will Change Your World” (MIT Technology Review, Feb ‘04) • Key to commercial success: low-cost T-ray source • Electromagnetic spectrum between high-frequency radio waves and far infrared light • 0.1-10 THz range  0.03 - 3 mm wavelength • Non-ionizing, causes negligible damage of materials • Many materials transparent, others exhibit unique absorption signature • Absorbed by water and humidity • Absorption length 10 cm – 10 km in air, depending on wavelength and humidity

32. Applications Non-Destructive Testing THz Security Scanning mmW Automotive Radar THz Medical Imaging

33. Conclusions • Metal-insulator diodes & detectors have been demonstrated • To 200 GHz and beyond • On CMOS integrated circuits • On plastic substrates • Double-insulator diodes provide enhanced performance • Metal-insulator modulators & transistors are feasible • Advantages include low cost, integratability, ultra-high speed, compatible with CMOS fabrication • Near-term applications include 60 GHz wireless links • Longer-term applications include terahertz wireless links, terahertz imaging, and ultra-high speed electronics

34. Extra Slides

35. Classical or Quantum Description? • Incident radiation • Electromagnetic waves or • QED photons (quanta) • Antenna signal • Current (classical) or • Surface plasmons (quanta) • Diode tunneling • Rectification (classical) or • Hot electrons (quanta) or • Quantum transitions

36. Features of Transistor • Ultra-fast metal-insulator nanotechnology transistors • Thin film: compatible with silicon ICs • Manufacturable at low cost narrow emitter stripe double-I emitter oxides B base metal C collector oxide E low  substrate

37. Double Insulator

38. Comparison: THz Sources • Efficient  up to 35% or higher DC-to-THz • High power  mW output for single device • Integrated  solid state, thin film

39. Emerging Market: Terahertz Imaging • Security • Bombs in packages: mail packages, luggage • Objects detected through-wall and through-clothes • Chemical and biological materials • Medical imaging • Oncology: imaging soft tissue for cancer • Dental images • Pharmaceuticals • Drug dosage testing • Drug discovery • Manufacturing non-destructive diagnostics • Packaged semiconductors • Plastic and foam materials • Material composition analysis: food, textiles, asbestos • Gas analysis: pollution monitoring, engine exhaust, astronomy • Defense • Imaging through obscurants (fog, smoke, etc.) • Chem/bio agent & target detection & identification • Free-space communications: high bandwidth & secure