**8. Acknowledgement**

This work was supported by ITESI, CONACYT under thematic network RedNyN agreement I0110/229/09, and PROMEP agreement 92434. The first author thank to his wife and son for their time and patience to realize this study.

#### **9. References**

58 VLSI Design

three-terminals, they are modeled by a bipolar junction transistor (BJT) or a metal-oxidesemiconductor field effect transistor (MOSFET), the latter being the most common for VLSI

Fig. 11. Cross section of resistive gas sensors and biosensors: (a) sensors based on carbon

minute quantities of gas molecules (Jesse et al., 2006; Mahar et al., 2007).

The use of complex morphologies and structures based on composites containing carbon nanotubes and polymers in the design of gas sensors, has allowed the detection of polar and nonpolar gases making use of the change of dielectric constant to enhance sensitivity to

Graphene is exploited due to its inexhaustible structural defects and functional groups. These are advantageous in electroanalysis and electrocatalysis for electrochemical applications such as gas sensors and biosensors. Physisorbed ambient impurities by graphene such as water and oxygen can produce an effect similar to hole-doping and therefore a behavior similar to a *p*-type material (Traversi et al., 2009). Then, the graphene can be exploited as a sensing material for the design of chemical and/or biochemical sensors. When graphene is doped, well-identified localized states are added and band gap is introduced to the electrical properties generating an interesting alternative to design sensors

The main changes to be realized in the optimization of performance of gas sensors are the search of methods which allow us to synthesize identical and reproducible CNTs will give place to gas sensors with high quality and high performance, independently of the type of

In accordance with the review proposed here, CNTs are very attractive as base material to the design of components for VLSI Design. Chemical modifications of CNTs allow to the designer improve the selectivity of the electrical properties for the different applications. In the future, the use of hybrid materials where carbon nanotubes are involved will be a priority, given that the use of composite materials to design electronic devices, circuits and sensors requires multiple physical and chemical properties that a unique material cannot provide by itself. In the search for reducing electrical resistance presented by carbon nanotubes, different strategies have been developed to improve the efficiency of interconnection between devices based on carbon nanotubes and metallic electrodes used to lead the electrical bias to them. The implementation of digital and analog circuits with CNFETs or graphene nanoribbons will produce a great advance toward VLSI design using nanoelectronics. Still, hurdles remain as it was described in each section of the chapter.

systems (Zhao et al., 2008).

(Barrios-Vargas et al., 2011).

**7. Conclusions** 

nanotubes, and (b) sensors based on graphene.

chemical functionalization required for the detection.


Carbon Nanotube- and Graphene Based Devices, Circuits and Sensors for VLSI Design 61

Ferry, D.K.; Goodnick, S.M. & Bird, J. (2009), *Transport in Nanostructures*, Second Edition,

Geim, A.K. & Novoselov, K.S. (2007), The Rise of Graphene, *Nature Materials*, Vol. 6, No. 3,

Geim, A.K. (2009), Graphene: Status and Prospects, *Science*, Vol. 324, No. 5934, pp. 1530-

Ginley, D. S. (2010), *Handbook of Transparent Conductors*, Springer, ISBN 978-1-4419-1637-2,

Giustiniani, A.; Tucci, V. & Zamboni, W. (2011), Carbon Nanotubes Bundled Interconnects:

Goel, A. K. (2007), *High-Speed VLSI Interconnections*, Second Edition, John Wiley & Sons,

Gruner, G. (2006), Carbon Nanotube Transistors for Biosensing Applications, *Analytical and* 

Guildi, D.M. & Martín, N. (2010), *Carbon Nanotubes and Related Structures: Synthesis,* 

Haruehanroengra, S. & Wang, W. (2007), Analyzing Conductance of Mixed Carbon

Hasan, S.; Salahuddin, S.; Vaidyanathan, M. & Alam, M.A. (2006), High-Frequency

Hatakeyama, R.; Li, Y.F.; Kato, T.Y. & Kaneko, T. (2010), Infrared Photovoltaic Solar Cells

Hayden, O. & Nielsch, K. (2011), *Molecular- and Nano-Tubes*, Springer, ISBN 978-1-4419-9442-

Hecht, D.S.; Hu, L. & Grüner, G. (2007), Electronic Properties of Carbon Nanotube/Fabric

Hierold, C. (2008), *Advanced Micro & Nanosystems Vol. 8 Carbon Nanotube Devices: Properties,* 

Hong, S.W.; Banks, T. & Rogers, J.A. (2010), Improved Density in Aligned of Single-Walled

Hosseini, A. & Shabro V. (2010), Thermally-aware Modeling and Performance Evaluation

Hou, P.-X.; Liu, C. & Cheng, H.-M. (2008), Purification of Carbon Nanotubes, *Carbon*, Vol.

Hu, L.; Gruner, G.; Gong, J.; Kim, C.-J. "CJ" & Hornbostel, B. (2007), Electrowetting Devices

Design Hints based on Frequency- and Time-Domain Crosstalk Analyses, *IEEE* 

*Characterization, Functionalization, and Applications*, Wiley-VCH, ISBN 978-3-527-

Nanotube Bundles for Interconnect Applications, *IEEE Electron Device Letters*, Vol.

Performance Projections for Ballistic Carbon-Nanotube Transistors, *IEEE* 

based on C60 Fullerene Encapsulated Single-Walled Carbon Nanotubes, *Applied* 

*Modeling, Integration and Applications*, Wiley-VCH, ISBN 978-3-527-31720-2, Federal

Carbon Nanotubes by Sequential Chemical Vapor Deposition on Quartz, *Advanced* 

for Single-Walled Carbon Nanotube-based Interconnects for Future High Performance Integrated Circuits, *Microelectronic Engineering*, Vol. 87, No. 10, pp.

with Transparent Single-Walled Carbon Nanotube Electrodes, *Applied Physics* 

Cambridge University Press, United States of America.

*Transactions on Electron Devices*, Vol. 58, No. 8, pp. 2702-2711.

ISBN 978-0-471-78046-5, United States of America.

*Bioanalytical Chemistry*, Vol. 384, No. 2, pp. 322-335.

*Transactions on Nanotechnology*, Vol. 5, No. 1, pp. 14-22.

Composites, *Current Applied Physics*, Vol. 7, No. 1, pp. 60-63.

*Physics Letters*, Vol. 97, No. 3, pp. 013104(3).

*Materials*, Vol. 22, No. 16, pp. 1826-1830.

32406-4, Federal Republic of Germany.

pp. 183-191.

United States of America.

28, No. 8, pp. 756-759.

4, United States of America.

Republic of Germany.

46, No. 15, pp. 2003-2025.

*Letters*, Vol. 90, No. 9, pp. 093124(3).

1955-1962.

1534.

Film-Si Schottky Contacts using Metal-Semiconductor-Metal Structures, *Applied Physics Letters*, Vol. 92, No. 24, pp. 243116(3).


Bradley, K.; Gabriel, J.-C.P.; Briman, M.; Star, A. and Grüner, G. (2003), Charge Transfer

Burghard, M.; Klauk, H. & Kern, K. (2009), Carbon-based Field-Effect Transistors for Nanoelectronics, *Advanced Materials*, Vol. 21, Nos. 25-26, pp. 2586-2600. Burke, P.J. (2004), AC Performance on Nanoelectronics: Towards a Ballistic THz Nanotube

Cao, Q.; Xia, M.-G.; Shim, M. & Rogers, J.A. (2006), Bilayer Organic-Inorganic Gate

Substrates, *Advanced Functional Materials*, Vol. 16, No. 18, pp. 2355-2362. Cao, Q.; Xia, M.; Kocabas, C.; Shim, M.; Rogers, J.A. & Rotkin, S.V. (2007), Gate Capacitance

Cao, Q. & Rogers, J.A. (2008), Random Networks and Aligned Arrays of Single-Walled

Cao, Q. & Rogers, J.A. (2009), Ultrathin Films of Single-Walled Carbon Nanotubes for

Chen, C. & Zhang, Y. (2009), *Nanowelded Carbon Nanotubes: From Field-Effect Transistors to* 

Chen, P.-C.; Shen, G.; Sukcharoenchoke, S. & Zhou, C. (2009), Flexible and Transparent

Chen, P.-C.; Sukcharoenchoke, S.; Ryu, K.; de Arco, L.G.; Badmaev, A.; Wang, C. & Zhou, C.

Chen, X.; Wang, H.; Wan, H.; Song, K & Zhou, G. (2011), Semiconducting States and

Cho, H.; Koo, K.-H.; Kapur, P. & Saraswat, K. C. (2008), Performance Comparisons between

Danilchenko, B. A.; Shpinar, L.I.; Tripachko, N.A.; Voitsihovska, E.A.; Zelensky, S.E. &

Facchetti, A. & Marks, T.J. (2010), *Transparent Electronics: From Synthesis to Applications*, First

Edition, John Wiley & Sons, ISBN 978-0-470-99077-3, Great Britain.

Nanotube Bundles, *Applied Physics Letters*, Vol. 97, No. 7, pp. 072106(3). Dong, X.; Lau, C.M.; Lohani, A.; Mhaisalkar, S.G.; Kasim, J.; Shen, Z.; Ho, X.; Rogers, J.A. &

*Solar Microcells*, Springer, ISBN 978-3-642-01498-7, Germany.

*Applied Physics Letters*, Vol. 94, No. 4, pp. 043113(3).

*Condensed Matter*, Vol. 23, No. 31, pp. 315304(8).

*Electron Device Letters*, Vol. 29, No. 1, pp. 122-124.

*Materials*, Vol. 20, No. 12, pp. 2389-2393.

Transistor, *Solid-State Electronics*, Vol. 48, Nos. 10-11, pp. 1981-1986.

*Physics Letters*, Vol. 92, No. 24, pp. 243116(3).

*Letters*, Vol. 90, No. 2, pp. 023516(3).

*Materials*, Vol. 21, No. 1, pp. 29-53.

pp. 218301(4).

pp. 259-272.

pp. 1900-1904.

Film-Si Schottky Contacts using Metal-Semiconductor-Metal Structures, *Applied* 

from Ammonia Physisorbed on Nanotubes, *Physical Review Letters*, Vol. 91, No. 21,

Dielectrics for High-Performance, Low-Voltage, Single-Walled Carbon Nanotube Thin-Film Transistors, Complementary Logic Gates, and p-n Diodes on Plastic

Coupling of Single-Walled Carbon Nanotube Thin-Film Transistors, *Applied Physics* 

Carbon Nanotubes for Electronic Device Applications, *Nano Research*, Vol. 1, No. 4,

Electronics and Sensors: A Review of Fundamental and Applied Aspects, *Advanced* 

Supercapacitor based on In2O3 Nanowire/Carbon Nanotube Heterogeneous Films,

(2010), 2,4,6-Trinitrotoluene (TNT) Chemical Sensing based on Aligned Single-Walled Carbon Nanotubes and ZnO Nanowires, *Advanced Materials*, Vol. 22, No. 17,

Transport in Metallic Armchair-Edged Graphene Nanoribbons, *Journal of Physics:* 

Cu/Low-*κ*, Carbon-Nanotube, and Optics for Future on-Chip Interconnects, *IEEE* 

Sundqvist, B. (2010), High Temperature Luttinger Liquid Conductivity in Carbon

Li, L.-J. (2008), Electrical Detection of Femtomolar DNA via Gold-Nanoparticle Enhancement in Carbon-Nanotube-Network Field-Effect Transistors, *Advanced* 


Carbon Nanotube- and Graphene Based Devices, Circuits and Sensors for VLSI Design 63

Kocabas, C.; Kim, H.-S.; Banks, T.; Rogers, J.A.; Pesetski, A.A.; Baumgardner, J.E.;

Kreupl, F.; Graham, A.P.; Duesberg, G.S.; Steinhögl, W.; Liebau, M.; Unger, E. & Hönlein, W.

Krompiewski, S. (2005), Spin-Polarized Transport through Carbon Nanotubes, *Physica Status* 

Law, M.; Goldberg, J. & Yang, P. (2004), Semiconductor Nanowires and Nanotubes, *Annual* 

Lefenfeld, M.; Blanchet, G. & Rogers, J.A. (2003), High-Performance Contacts in Plastic

Lekakou, C.; Moudam, O.; Markoulidis, F.; Andrews, T.; Watts, J.F. & Reed, G. T. (2011),

Léonard, F. (2009), *The Physics of Carbon Nanotube Devices*, William Andrew, ISBN 978-0-

Li, H.; Yin, W.-Y.; Banerjee, K. & Mao, J.-F. (2008), Circuit Modeling and Performance

Li, H.; Xu, C.; Srivastava, N. & Banerjee, K. (2009), Carbon Nanomaterials for Next-

Li, J.; Ye, Q.; Cassell, A.; Ng, H.T.; Stevens, Ramsey; Han, Jie & Meyyappan, M. (2003),

Lin, A.; Patil, N.; Ryu, K.; Badmaev, A.; De Arco, L.G.; Zhou, C.; Mitra, S. & Wong, H.-S.P.

Nanotube FETs, *IEEE Transactions on Nanotechnology*, Vol. 8, No. 1, pp. 4-9. Lin, C.-T.; Hsu, C.-H.; Lee, C.-H. & Wu, W.-J. (2011), Inkjet-Printed Organic Field-Effect

Lin, Y.M.; Valdes-Garcia, A.; Han, S.-J.; Farmer, D.B.; Meric, I.; Sun, Y.; Wu, Y.;

Graphene Integrated Circuit, *Science*, Vol. 332, No. 6035, pp. 1294-1297. Liu, X.; Luo, Z.; Han, S.; Tang, T.; Zhang, D. & Zhou, C. (2005), Band Engineering of Carbon

*Transactions on Electron Devices*, Vol. 56, No. 9, pp. 1799-1821.

*Solidi B*: *Basic Solid State Physics*, Vol. 242, No. 2, pp. 226-233.

*Review of Materials Research*, Vol. 34, pp. 83-122.

*Nanotechnology*, Vol. 2011, Article ID 409382(8).

*Electron Devices*, Vol. 55, No. 6, pp. 1328-1337.

*Physics Letters*, Vol. 86, No. 24, pp. 243501(3).

8155-1573-9, United States of America.

Vol. 82, No. 15, pp. 1566791(3).

3206-3215.

1188-1191.

142890(7).

Vol. 64, Nos. 1-4, pp. 399-408.

Krishnaswamy, S.V. & Zhang, H. (2008), Radio Frequency Analog Electronics based on Carbon Nanotube Transistors, *PNAS*, Vol. 105, No. 5, pp. 1405-1409. Koo, K.-H.; Cho, H.; Kapur, P. & Saraswat, K.C. (2007), Performance Comparisons between

Carbon Nanotubes, Optical, and Cu for Future High-Performance On-Chip Interconnect Applications, *IEEE Transactions on Electron Devices*, Vol. 54, No. 12, pp.

(2002), Carbon Nanotubes in Interconnect Applications, *Microelectronic Engineering*,

Transistors and Logic Gates That Use Printed Electrodes of DNNSA-PANI Doped with Single-Walled Carbon Nanotubes, *Advanced Materials*, Vol. 15, No. 14, pp.

Carbon-based Fibrous EDLC Capacitors and Supercapacitors, *Journal of* 

Analysis of Multi-Walled Carbon Nanotube Interconnects, *IEEE Transactions on* 

Generation Interconnects and Passives: Physics, Status, and Prospects, *IEEE* 

Bottom-Up Approach for Carbon Nanotube Interconnects, *Applied Physics Letters*,

(2009), Threshold Voltage and On-Off Ratio Tuning for Multiple-Tube Carbon

Transistor by Using Composite Semiconductor Material of Carbon Nanoparticles and Poly(3-Hexylthiophene), *Journal of Nanotechnology*, Vol. 2011, Article ID

Dimitrakopoulos, C.; Grill, A.; Avouris, P. & Jenkins, K.A. (2011), Wafer-Scale

Nanotube Field-Effect Transistors via Selected Area Chemical Gating, *Applied* 


Hur, S.-H.; Khang, D.-Y.; Kocabas, C. & Rogers, J.A. (2004), Nanotransfer Printing by Use of

Ishikawa, F.N.; Stauffer, B.; Caron, D.A. & Zhou, C. (2009), Rapid and Label-Free Cell

Ishikawa, F.N.; Curreli, M.; Olson, C.A.; Liao, H.-I.; Sun, R.; Roberts, R.W.; Cote, R.J.;

Jain, D.; Rouhi, N.; Rutherglen, C.; Densmore, C. G.; Doorn, S. K. & Burke, P.J. (2011), Effect

Jamaa, M.H.B. (2011), *Regular Nanofabrics in Emerging Technologies: Design and Fabrication* 

Javey, A. (2008), The 2008 Kavli Prize in Nanoscience: Carbon Nanotubes, *ACS Nano*, Vol. 2,

Javey, A. & Kong, J. (2009), *Carbon Nanotube Electronics*, Springer, ISBN 978-0-387-36833-7,

Jia, J.; Guan, W.; Sim, M.; Li, Y. & Li, H. (2008), Carbon Nanotubes based Glucose Needle-

Jia, Y.; Cao, A.; Bai, X.; Li, Z.; Zhang, L.; Guo, N.; Wei, J.; Wang, K.; Zhu, H.; Wu, D. &

Joachim, C.; Gimzewski, J.K. & Aviram, A. (2000), Electronics using Hybrid-Molecular and

Kang, S.J.; Kocabas, C.; Kim, H.-S.; Cao, Q.; Meitl, M.A.; Khang, D.-Y. & Rogers, J. A. (2007),

Kocabas, C.; Hur, S.-H.; Gaur, A.; Meitl, M.A.; Shim, M. & Rogers, J.A. (2005), Guided

Kocabas, C.; Shim, M. & Rogers, J.A. (2006), Spatially Selective Guided Growth of High-

for Electronic Applications, *Nano Letters*, Vol. 7, No. 11, pp. 3343-3348. Kanungo, M.; Malliaras, G.G. & Blanchet, G.B. (2010), High Performance Organic

Deficient Olefin, *Applied Physics Letters*, Vol. 97, No. 5, pp. 053304(3). Kim, G.; Bernholc, J. & Kwon, Y.-K. (2010), Band Gap Control of Small Bundles of Carbon

Mono-Molecular Devices, *Nature*, Vol. 408, No. 6812, pp. 541-548.

Ajayan, P.M. (2011), Achieving High Efficiency Silicon-Carbon Nanotube Heterojunction Solar Cells by Acid Doping, *Nano Letters*, Vol. 11, No. 5, pp. 1901-

Printed Multilayer Superstructures of Aligned Single-Walled Carbon Nanotubes

Transistors: Percolation Arrays of Nanotubes Functionalized with an Electron

Nanotubes using Applied Electric Fields: A Density Functional Theory Study,

Growth of Large-Scale, Horizontally Aligned Arrays of Single-Walled Carbon Nanotubes and Their Use in Thin-Film Transistors, *Small*, Vol. 1, No. 11, pp. 1110-

Coverage Arrays and Random Networks of Single-Walled Carbon Nanotubes and Their Integration into Electronic Devices, *Journal of the American Chemical Society*,

Arrays, *Journal of Nanomaterials*, Vol. 2011, Article ID 174268(7).

*Letters*, Vol. 85, No. 23, pp. 5730-5732.

States of America.

1905.

1116.

No. 7, pp. 1329-1335.

United States of America.

*Bioelectronics*, Vol. 24, No. 10, pp. 2967-2972.

Conditions, *ACS Nano*, Vol. 4, No. 11, pp. 6914-6922.

Type Biosensor, *Sensors*, Vol. 8, No. 3, pp. 1712-1718.

*Applied Physics Letters*, Vol. 97, No. 6, pp. 063113(3).

Vol. 128, No. 14, pp. 4540-4541.

Noncovalent Surface Forces: Applications to Thin-Film Transistors that Use Single-Walled Carbon Nanotube Networks and Semiconducting Polymers, *Applied Physics* 

Detection by Metal-Cluster-decorated Carbon Nanotube Biosensors, *Biosensors and* 

Thompson, M.E. & Zhou, C. (2010), Importance of Controlling Nanotube Density for Highly Sensitive and Reliable Biosensors Functional in Physiological

of Source, Surfactant, and Deposition Process on Electronic Properties of Nanotube

*Methods for Nanoscale Digital Circuits*, Springer, ISBN 978-94-007-0649-1, United


Carbon Nanotube- and Graphene Based Devices, Circuits and Sensors for VLSI Design 65

Rueckes, T.; Kim, K.; Joselevich, E.; Tseng, G.Y.; Cheung, C.-L. & Lieber, C.M. (2000) Carbon

Sangwan, V.K.; Behnam, A.; Ballarotto, V.W.; Fuhrer, M.S.; Ural, A. & Williams, E.D. (2010),

Schaman-Diamand, Y.; Osaka, T.; Datta, M. & Ohba, T. (2009), *Advanced Nanoscale ULSI* 

Singh, D.V.; Jenkins, K.A.; Appenzeller, J.; Neumayer, D.; Grill, A. & Wong, H.-S. (2004),

Sinha, N.; Ma, J. & Yeow, J.T.W. (2006), Carbon Nanotube-based Sensors, *Journal of* 

Srivastava, N. & Banerjee, K. (2004), Interconnect Challenges for Nanoscale Electronic

Srivastava, N.; Li, H.; Kreupl, F. & Banerjee, K. (2009), On the Applicability of Single-Walled

Star, A.; Han, T.-R.; Joshi, V.; & Stetter, J.R. (2004) Sensing with Nafion Coated Carbon Nanotube Field-Effect Transistors, *Electroanalysis*, Vol. 16, Nos. 1-2, pp. 108-112. Tan, C.S.; Gutmann, R.J. & Reif, L.R. (2008), *Wafer Level 3-D ICs Process Technology*, Springer,

Terrones, M. (2003), Science and Technology of the Twenty-First Century: Synthesis,

Terrones, M. (2004), Carbon Nanotubes: Synthesis and Properties, Electronic Devices and

Traversi, F.; Russo, V. & Sordan, R. (2009), Integrated Complementary Graphene Inverter,

Tseng, Y.-C.; Xuan, P.; Javey, A.; Malloy, R.; Wang, Q.; Bokor, J. & Dai, H. (2004), Monolithic

Tulevski, G.S.; Hannon, J.; Afzali, A.; Chen, Z.; Avouris, P. & Kagan, C.R. (2007), Chemically

Vaillancourt, J.; Zhang, H.; Vasinajindakaw, P.; Xia, H.; Lu, X.; Han, X.; Janzen, D.C.; Shin,

Vasileska, D. & Goodnick, S.M. (2011), *Nano-Electronic Devices: Semiclassical and Quantum Transport Modeling*, Springer, ISBN 978-1-4419-8839-3, United States of America.

Circuits, *TMS Journal of Materials (JOM)*, Vol. 56, No. 10, pp. 30-31.

*Applied Physics Letters*, Vol. 97, No. 4, pp. 043111(3).

*Transactions on Nanotechnology*, Vol. 3, No. 3, pp. 383-387.

*Nanoscience and Nanotechnology*, Vol. 6, No. 3, pp. 573-590.

ISBN 978-0-387-76532-7, United States of America.

*Applied Physics Letters*, Vol. 34, No. 22, pp. 223312(3).

*Applied Physics Letters*, Vol. 93, No. 24, pp. 243301(3).

*Science*, Vol. 289, pp. 94-97.

United States of America.

8, No. 4, pp. 542-559.

325-377.

11964-11968.

*Research*, Vol. 33, pp. 419-501.

*Letters*, Vol. 4, No. 1, pp. 123-127.

Nanotube-based Nonvolatile Random Access Memory for Molecular Computing,

Optimizing Transistor Performance of Percolating Carbon Nanotube Networks,

*Interconnects: Fundamentals and Applications*, Springer, ISBN 978-0-387-95867-5,

Frequency Response of Top-Gated Carbon Nanotube Field-Effect Transistors, *IEEE* 

Carbon Nanotubes as VLSI Interconnects, *IEEE Transactions on Nanotechnology*, Vol.

Properties, and Applications of Carbon Nanotubes, *Annual Review of Materials* 

Other Emerging Applications, *International Materials Reviews*, Vol. 49, No. 6, pp.

Integration of Carbon Nanotube Devices with Silicon MOS Technology, *Nano* 

Assisted Directed Assembly of Carbon Nanotubes for the Fabrication of Large-Scale Device Arrays, *Journal of the American Chemical Society*, Vol. 129, No. 39, pp.

W.-S.; Jones, C.S.; Stroder, M.; Chen, M.Y.; Subbaraman, H.; Chen, R.T.; Berger, U. & Renn, M. (2008), All Ink-Jet-Printed Carbon Nanotube Thin-Film Transistor on a Polyimide Substrate with an Ultrahigh Operating Frequency of Over 5 GHz,


Lu, W. & Lieber, C.M. (2007), Nanoelectronics from the Bottom Up, *Nature Materials*, Vol. 6,

Mahar, B.; Laslau, C.; Yip, R. & Sun, Y. (2007), Development of Carbon Nanotube-based

Mallick, G.; Griep, M.H.; Ayajan, P.M. & Karna, S.P. (2010), Alternating Current-to-Direct

Mamalis, A.G.; Vogtländer, L.O.G. & Markopoulos, A. (2004), Nanotechnology and

Nismi, N.A.; Adikaari, A.A.D.T. & Silva, S.R.P. (2010), Functionalized Multiwall Carbon

Nogueira, A. F.; Lomba, B.S.; Soto-Oviedo, M.A.; Correia, C.R.D.; Corio, P.; Furtado, C.A. &

*Nanomaterials, Interfaces and Hard Matter*, Vol. 111, No. 49, pp. 18431-18438. Nojeh, A. & Ivanov, A. (2010), Wireless Interconnect and the Potential for Carbon Nanotubes, *IEEE Design & Test of Computers*, Vol. 27, No. 4, pp. 44-52. Nouchi, R.; Tomita, H.; Ogura, A.; Shiraishi, M. & Kataura, H. (2008), Logic Circuits using

Novoselov, K.S.; Geim, A.K.; Morozov, S.V.; Jiang, D.; Zhang, Y.; Dubonos, S.V.; Grigorieva,

Oliveira, A.C. & Mascaro, L.H. (2011), Evaluation of Acetylcholinesterase Biosensor based

Papanikolaou, A.; Soudris, D. & Radojcic, R. (2011), *Three Dimensional System Integration: IC* 

Pesetski, A.A.; Baumgardner, J. E.; Krishnaswamy, S.V.; Zhang, H.; Adam, J. D.; Kocabas, C.;

Philip-Wong, H.-S. & Akinwande, D. (2011), *Carbon Nanotube and Graphene Device Physics*, Cambridge University Press, ISBN 978-0-521-51905-2, United Kingdom. Reddy, D.; Register, L.F.; Carpenter, G.D. & Banerjee, S.K. (2011), Graphene Field-Effect Transistors, *Journal of Physics D: Applied Physics*, Vol. 44, No. 31, pp. 313001(20). Rivas, G.A.; Rubianes, M.D.; Pedano, M.L.; Ferreyra, N.F.; Luque, G. & Miscoria, S.A. (2009),

Rowell, M.W.; Topinka, M.A.; McGehee, M.D.; Prall, H.-J.; Dennler, G.; Sariciftci, N.S.; Hu,

*Journal of Analytical Chemistry*, Vol. 2011, Article ID 974216 (6).

Publishers, ISBN 978-1-607-41314-1, United States of America.

Electrodes, *Applied Physics Letters*, Vol. 88, No. 23, pp. 233506(3).

*Applied Physics Letters*, Vol. 93, No. 12, pp. 123506(2).

Current Power Conversion by Single-Wall Carbon Nanotube Diodes, *Applied* 

Nanostructured Materials: Trends in Carbon Nanotubes, *Precision Engineering*, Vol.

Nanotubes incorporated Polymer/Fullerene Hybrid Photovoltaics, *Applied Physics* 

Hümmelgen, I.A. (2007), Polymer Solar Cells using Single-Wall Carbon Nanotubes Modified with Thiophene Pedant Groups, *Journal of Physical Chemistry C:*

Solution-Processed Single-Walled Carbon Nanotube Transistors", *Applied Physics* 

I.V. & Firsov, A.A. (2004), Electric Field Effect in Atomically Thin Carbon Films,

on Carbon Nanotube Paste in the Determination of Chlorphenvinphos, *International* 

*Stacking Process and Design*, Springer, ISBN 978-1-4419-0961-9, United States of

Banks, T. & Rogers, J.A. (2008), A 500 MHz Carbon Nanotube Transistor Oscillator,

*Carbon Nanotubes: A New Alternative for Electrochemical Sensors*, Nova Science

L. & Gruner, G. (2006), Organic Solar Cells with Carbon Nanotube Network

Sensors – A Review, *IEEE Sensors Journal*, Vol. 7, No. 2, pp. 266-284.

Marulanda, J.M. (2010), *Carbon Nanotubes*, In-Tech, ISBN 978-953-307-054-4, Croatia.

*Physics Letters*, Vol. 96, No. 23, pp. 233109(3).

*Letters*, Vol. 97, No. 3, pp. 033105(3).

*Letters*, Vol. 92, No. 25, pp. 253507(3).

*Science*, Vol. 306, No. 5696, pp. 666-669.

No. 11, pp. 841-850.

28, No. 1, pp. 16-30.

America.


**1. Introduction**

2004), (Brooks D., 2003).

mathematical model is presented.

**0**

**4**

*Mexico*

**Impedance Matching in VLSI Systems**

The continuous scaling process into submicrometric dimensions of silicon based devices has allowed the integration of a large number of systems in a single chip. Besides, the operating frequencies of such systems are higher and a large amount of information can be processed in a short period of time. On the other hand, while the core frequencies are increasing, higher data rates for off-chip interconnections become necessary, for example a processor that communicates with the memory in order to process information. Unfortunately, at high rates the signal wave length is comparable with the physical length of the interconnections, because of this, parasitic and transmission line effects have to be taken into account. As a consequence, the transmitted signal integrity is degraded resulting in communication errors (Thierauf S.,

It has been shown that, for modern off-chip communication systems, current mode signaling offers several advantages over voltage-mode at high data rates (Juan, 2007), but they need to be matched in impedance to the interconnection line. However, impedance matching requires termination resistors. Moreover, due to the large number of input/output circuits in a single chip, terminations have to be placed on-chip (Fan Y. & Smith J., 2003) so that the PCB area is not increased. One of the most important transmission line effects that degrades signal integrity in these signaling schemes is reflection loss. In this case, signal reflections traveling trough the line are present in either driver to receiver or receiver to driver directions. Unfortunately, it is difficult to achieve perfect matching of impedances due to the large process variations in the fabrication of interconnection lines and the different traces between them (Ramachandran N. et. al., 2003). Also, temperature variations and external effects are present inside and outside the chip. As a conclusion, impedance matching techniques must

be developed in order to automatically adapt the impedance variations of the line.

In this chapter systems for on-die automatic impedance matching for off-chip signaling are described. In order to perform the automatic matching operation an algorithm that integrates the sign of the impedance matching error and the sign of the coupling branch current is implemented. The advantage of this algorithm is that it works without interfering with the driver operation. Computer simulations of layout extractions are presented. Also, a system of knowlegde- based impedance matching which avoids the calculation of a complex

Díaz Méndez J. Alejandro1, López Delgadillo Edgar2

<sup>1</sup>*National Institute for Astrophysics, Optics and Electronics*

and Arroyo Huerta J. Erasmo1

<sup>2</sup>*Universidad Autónoma de Aguascalientes*

