The Role of Graphene in Semiconductor Technologies

By Shaloo Rakheja

Massachusetts Institute of Technology (MIT), Cambridge, MA

Published on

Abstract

With its rich physical properties, the novel 2-D carbon-based material graphene is expected to play an important role in the advancement of semiconductor technologies. In a recent poll conducted by the International Technology Roadmap for Semiconductors (ITRS), graphene is named as the material most likely to have the greatest impact on geometric scaling. As a two-dimensional material, graphene has a limited phase space for scattering of electrons; hence, the electrons in graphene can have a long mean free path – a property that can be utilized to build a variety of high frequency analog devices and to implement low-power on-chip interconnects. Further, the ambipolar characteristics of graphene allow frequency doubler circuits implemented with a single transistor – something that is not possible with silicon transistors. In my talk, I will examine the requirements and challenges that must be met for graphene electronics, and discuss possible solutions.

In the first part of the talk, I will describe on-chip interconnect applications with single- and multi-layer graphene nanoribbons (GNR). I will present physical models for carrier mobility and per-unit-length resistance for interconnects. The impact of imperfect coupling of contacts with graphene interconnect leads to a non-uniform distribution of current in the graphene multi-layer interconnect structure. I will quantify the limits imposed on the maximum benefit of graphene interconnects due to such imperfect contact coupling and interaction of graphene electrons with the substrate and edge states.

In the second part of the talk, I will present an ambipolar virtual source (AVS) charge-current compact model for nanoscale graphene transistors applicable in radio frequency (RF) circuits. A self-consistent channel-charge- partitioning model valid from drift-diffusive to ballistic transport conditions supplements the transport model. The model has been extensively calibrated with experimental DC I-V and s-parameter measurements of devices with gate lengths from 650 nm to 40 nm. This has allowed the scaling of mobility and virtual source injection velocity of carriers in graphene transistors to be studied for the first time.

I will conclude my talk with opportunities for extending graphene technologies to solar cells, optical modulators, and photo-detectors.

Bio

Shaloo Rakheja Shaloo Rakheja received the B.Tech. degree in electrical engineering from Indian Institute of Technology, Kanpur, India, in 2005, and the M.S. and Ph.D. degrees in electrical and computer engineering from the Georgia Institute of Technology in 2009 and 2012, respectively. She worked as a Component Engineer at Intel, Bangalore in 2005 and later as an Analog Engineer at Freescale Semiconductor, Noida from 2006 to 2007. She is currently a Postdoctoral Associate with Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge. Over the last five years, she has co-authored twenty-seven international conference and refereed journal publications. She has also co-authored four book chapters and contributed to the chapter on Emerging Interconnects in ITRS 2011. She received the Intel PhD Fellowship for the academic year 2011-2012. She also received the ECE Graduate Research Assistant Excellence Award for the academic year 2011-2012. Her research interests are in alternate state variable devices, non-Boolean and analog-like system architectures, neuromorphic or other biologically-inspired devices, energy harvesting for sensor networks and other mobile devices, and flexible and transparent electronics and optoelectronics for ubiquitous systems.

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Cite this work

Researchers should cite this work as follows:

  • Shaloo Rakheja (2014), "The Role of Graphene in Semiconductor Technologies," https://nanohub.org/resources/21272.

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Location

Birck Technology Center, Room 1001, Purdue University, West Lafayette, IN

The Role of Graphene in Semiconductor Technologies
  • The role of graphene in semiconductor technologies 1. The role of graphene in semico… 0
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  • The graphene age 2. The graphene age 149.91658324991658
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  • Outline 3. Outline 196.76343009676344
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  • Part-1: on-chip interconnects 4. Part-1: on-chip interconnects 285.51885218551888
    00:00/00:00
  • Why 5. Why "graphene" for on-chip int… 371.30463797130466
    00:00/00:00
  • Intrinsic mean free path in graphene 6. Intrinsic mean free path in gr… 417.48415081748419
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  • Patterned graphene on a substrate 7. Patterned graphene on a substr… 456.65665665665665
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  • Mobility of graphene on substrate 8. Mobility of graphene on substr… 517.98465131798469
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  • Mobility of patterned graphene on substrate 9. Mobility of patterned graphene… 579.2459125792459
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  • Multi-layer graphene nanoribbons (ML-GNRs) for interconnect applications 10. Multi-layer graphene nanoribbo… 689.92325658992331
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  • Current distribution for top-contacted ML-GNRs 11. Current distribution for top-c… 775.20854187520854
    00:00/00:00
  • Performance of ML-GNRs 12. Performance of ML-GNRs 816.34968301634967
    00:00/00:00
  • Comparison of delay for ML-GNRs and Cu 13. Comparison of delay for ML-GNR… 894.1274607941275
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  • Comparison of energy dissipation for ML-GNRs and Copper 14. Comparison of energy dissipati… 955.35535535535541
    00:00/00:00
  • Summary of part-I 15. Summary of part-I 987.2539205872539
    00:00/00:00
  • Part-II Graphene for analog RF circuits 16. Part-II Graphene for analog RF… 1024.3910577243912
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  • Modeling efforts in GFETs for RF applications 17. Modeling efforts in GFETs for … 1528.3283283283283
    00:00/00:00
  • Physics of virtual source model 18. Physics of virtual source mode… 1574.5745745745746
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  • Virtual source model for GFETs 19. Virtual source model for GFETs 1636.3697030363699
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  • Virtual source charges: compact model 20. Virtual source charges: compac… 1695.3620286953621
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  • Virtual source charges: numerical model 21. Virtual source charges: numeri… 1770.1034367701036
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  • Virtual source charges: comparison of compact and numerical models 22. Virtual source charges: compar… 1840.8074741408075
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  • Virtual source charges: adjustment in Qdis and EOT 23. Virtual source charges: adjust… 1897.6976976976978
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  • Asymmetry in carrier transport 24. Asymmetry in carrier transport 1940.9075742409077
    00:00/00:00
  • Asymmetry in carrier transport: phenomenological circuit model 25. Asymmetry in carrier transport… 2000.4337671004339
    00:00/00:00
  • Dynamic model for GFETs: key equations- 1/2 26. Dynamic model for GFETs: key e… 2077.8778778778778
    00:00/00:00
  • Dynamic model for GFETs: key equations- 2/2 27. Dynamic model for GFETs: key e… 2152.3857190523859
    00:00/00:00
  • Simulation of channel charges- 1/2 28. Simulation of channel charges-… 2224.5578912245578
    00:00/00:00
  • Simulation of channel charges- 2/2 29. Simulation of channel charges-… 2254.6212879546215
    00:00/00:00
  • Capacitance versus voltage: simulation result 30. Capacitance versus voltage: si… 2276.1094427761095
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  • GFET RF model calibration with experiments LG = 650 nm, 300 nm from IBM 31. GFET RF model calibration with… 2359.4594594594596
    00:00/00:00
  • GFET RF model calibration with experiments LG = 140 nm, 40 nm from IBM 32. GFET RF model calibration with… 2402.6693360026693
    00:00/00:00
  • GFET RF model calibration with experiments LG =[ 650, 300, 140, 40] nm, IBM 33. GFET RF model calibration with… 2540.373707040374
    00:00/00:00
  • Analysis of carrier mean free path and effective mobility- 1/2 34. Analysis of carrier mean free … 2644.377711044378
    00:00/00:00
  • Analysis of carrier mean free path and effective mobility- 1/2 35. Analysis of carrier mean free … 2904.3376710043376
    00:00/00:00
  • Analysis of ballistic velocity- 1/2 36. Analysis of ballistic velocity… 3006.63997330664
    00:00/00:00
  • Analysis of ballistic velocity- 2/2 37. Analysis of ballistic velocity… 3063.6302969636304
    00:00/00:00
  • Graphene frequency doubler circuits 38. Graphene frequency doubler cir… 3105.4721388054722
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  • Simulating frequency doublers with GFET RF model 39. Simulating frequency doublers … 3167.6009342676011
    00:00/00:00
  • Summary of part II: graphene VS model for RF applications 40. Summary of part II: graphene V… 3217.8511845178514
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  • The graphene age 41. The graphene age 3262.0620620620621
    00:00/00:00
  • Graphene electrodes in PVs 42. Graphene electrodes in PVs 3280.4471137804471
    00:00/00:00
  • Graphene photonics: interaction of light and carriers in graphene 43. Graphene photonics: interactio… 3371.3713713713714
    00:00/00:00
  • Graphene and light: proposed research 44. Graphene and light: proposed r… 3423.39005672339
    00:00/00:00
  • 2D nanoelectronics 45. 2D nanoelectronics 3497.3306639973307
    00:00/00:00