Helena Silva


Information Technologies Engineering Bldg., 457


Google Scholar Profile – Helena Silva

Research Group PageNanoelectronics Lab

Ph.D., Applied Physics, Cornell University (2005)
Licenciatura, Engineering Physics, Tecnico Lisboa, Universidade de Lisboa (1998)

Research Interests

Nanoelectronic devices, electronic and thermal transport at small scales, non-volatile memory devices, phase-change memory, thermoelectric materials and devices, nanofabrication techniques.


Book Chapters

M. Singh, C. Ghosh, S. Tripathi, P. Kotula, G. Bakan, H. Silva, C. B. Carter, TEM Studies of Segregation in a Ge–Sb–Te Alloy During Heating, in Applications of Microscopy in Materials and Life Sciences, Springer 2021.

N. Noor and H. Silva, Phase Change Memory for Physical Unclonable Functions, in Applications of Emerging Memory Technology, Springer Singapore 2020,https://doi.org/0.1007/978-981-13-8379-3.

R. Khan, N. Noor, J. Scoggin, C. Lu, M. vanDijk, A. Gokirmak, H. Silva, Phase-change memory and its applications in hardware security, in Security Opportunities in Nano Devices and Emerging Technologies, CRC Press 2017, https://doi.org/10.1201/9781315265056.

A. Faraclas, A. Gokirmak, H. Silva, Phase-change memories and electrothermal modeling, in Nanoscale Semiconductor Memories: Technology and Applications, CRC Press 2014, https://doi.org/10.1201/b16236

Journal Articles

62) ABM Talukder, B Smith, M Akbulut, F Dirisaglik, H Silva, A Gokirmak, Temperature Dependent Characteristics and Electrostatic Threshold Voltage Tuning of Accumulated Body MOSFETs, IEEE Transactions on Electron Devices 69 (8), 4138-4143 (2022).

61) MTB Kashem, J Scoggin, H Silva, A Gokirmak, Finite Element Modeling of Thermoelectric Effects in Phase Change Memory Cells, Electrochemical Society Transactions 108 (1), 3 (2022).

60) MTB Kashem, S Muneer, L Adnane, F Dirisaglik, A Gokirmak, H Silva, Calculation of the Energy Band Diagram and Estimation of Electronic Transport Parameters of Metastable Amorphous Ge2Sb2Te5, Electrochemical Society Transactions 108 (1), 29 (2022).

59) RS Khan, NH Kan’an, J Scoggin, H Silva, A Gokirmak, R. Khan, Computational Analysis of Multi-contact Phase Change Device for Toggle Logic Operations, Materials Science in Semiconductor Processing, Materials Science in Semiconductor Processing 134, 106042 (2021).

58) S Muneer, G Bakan, A Gokirmak, H Silva, Incorporation of GTR (generation–transport–recombination) in semiconductor simulations, Journal of Applied Physics 129 (5), 055702 (2021).

57) MK Singh, C Ghosh, S Tripathi, P Kotula, G Bakan, H Silva, CB Carter, TEM Studies of Segregation in a Ge–Sb–Te Alloy During Heating, Applications of Microscopy in Materials and Life Sciences, 105-114 (2021).

56) J. Scoggin, H. Silva, A. Gokirmak, Field Dependent Conductivity and Threshold Switching in Amorphous Chalcogenides – Modeling and Simulations of Ovonic Threshold Switches and Phase Change Memory Devices, Journal of Applied Physics 128 (23), 234503 (2020).

55) N. Noor, S. Muneer, R. S. Khan, A. Gorbenko, L. Adnane, M. T. Kashem, J. Scoggin, F. Dirisaglik, A. Cywar, A. Gokirmak, and H.  Silva, Reset Variability in Phase Change Memory for Hardware Security Applications, IEEE Trans. on Nanotechnology 20, 75-82 (2020).

54) Nadim Kanan Raihan Sayeed Khan Zachary Woods Helena Silva Ali Gokirmak, Phase‐Change Logic via Thermal Cross‐Talk for Computation in Memory, Physica Status Solidi (RRL) – Rapid Research Letters 15, 3 (2020).

53) N. Noor, S. Muneer, R. Khan, A. Gorbenko, H. Silva, Amorphized Length and Variability in Phase Change Memory Line Cells, Beilstein Journal of Nanotechnology 11 (1), 1644-1654 (2020).

52) N. Noor, S. Muneer, R. S. Khan, A. Gorbenko, and H. Silva, Enhancing Programming Variability in Multi-bit Phase Change Memory Cells for Security, IEEE Trans. on Nanotechnology 19, 820 – 828 (2020).

51) M. Singh, C. Ghosh, B. Miller, P. Kotula, S. Tripathi, J. Watt, G. Bakan, H. Silva, C. B. Carter, In-situ TEM Study of Crystallization and Chemical Changes in an Oxidized Uncapped Ge2Sb2Te5 Film, Journal of Applied Physics, DOI: 10.1063/5.0023761 (2020)

50) R. Khan, F. Dirisaglik, A. Gokirmak, H. Silva, Resistance drift in Ge2Sb2Te5 phase change memory line cells at low temperatures and its response to photoexcitation, Applied Physics Letters. 116 (25), 253501 (2020).

49) A. Cywar, Z. Woods, S. Kim, M. BrightSky, N. Sosa, Y. Zhu, H. S. Kim, H. K. Kim, C. Lam, A. Gokirmak, H. Silva, Modeling of void formation in phase change memory devices, Solid-State Electronics, 164, 107684 (2020).

48) S. Tripathi, P. Kotula, M. Singh, C. Ghosh, G. Bakan, H. Silva, C. B. Carter, C Barry, Role of oxygen on chemical segregation in uncapped Ge2Sb2Te5 thin films on silicon nitride, ECS Journal of Solid State Science and Technology (2020).

47) J. Scoggin, Z. Woods, H. Silva, A. Gokirmak, Modeling heterogeneous melting in phase change memory devices, Applied Physics Letters 114, 043502 (2019).

46) Sadid Muneer, Jake Scoggin, Faruk Dirisaglik, Lhacene Adnane, Adam Cywar, Gokhan Bakan, Kadir Cil, Chung Lam, Helena Silva, and Ali Gokirmak, “Activation Energy of Metastable Amorphous Ge2Sb2Te5 from Room Temperature to Melt,” AIP Advances 2158-3226 (2018).

45) J. Scoggin, R. Khan, H. Silva, and A. GokirmakModeling and Impacts of the Latent Heat of Phase Change and Specific Heat for Phase Change Materials,” Appl. Phys. Lett. 112 (19), 193502 (2018).

44) Mustafa B. Akbulut , Faruk Dirisaglik, Student Member, IEEE, Adam Cywar, Azer Faraclas, Douglas Pence, Jyotica Patel, Steven Steen, Ron W. Nunes, Helena Silva, and Ali Gokirmak, “Nanoscale Accumulated Body Si nMOSFETs,” IEEE Transactions on Electron Devices, http://10.1109/TED.2018.2809643ices, PP, 99 (2018).

43) L. Adnane, F. Dirisaglik, A. Cywar, K. Cil, Y. Zhu, C. Lam, A. F. M. Anwar, A. Gokirmak, and H. Silva, “High temperature electrical resistivity and Seebeck coefficient of Ge2Sb2Te5 thin films,” Journal of Applied Physics 122, 125104 (2017).

42) G. Bakan, B. Gerislioglu, F. Dirisaglik, Z. Jurado, L. Sullivan, A. Dana, C. Lam5, A. Gokirmak and H. Silva, “ Extracting the temperature distribution on a phase-change memory cell during crystallization,” Journal of Appl. Phys. 120, 164504 (2016).

41) A. Deschenes, S. Muneer, M. Akbulut, A.Gokirmak and H. Silva, Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory, Beilstein J. Nanotechnol. 2016, 7, 1676–1683 (2016).

40) L. Adnane, A. Gokirmak and H. Silva, “High temperature Hall measurement setup for thin film characterization,” Rev. Sci. Instrum. 87, 075117 (2016).

39) N. Kan’an, H. Silva and A. Gokirmak, “Phase-change pipe for non-volatile routing,” Journal of the Electron Devices Society 4, 2, 72-75 (2016).

38) N. Noor, L. Lucera, T. Capuano, V. Manthina, A. G. Agrios, H. Silva and A. Gokirmak, “Blue and white light emission from zinc oxide nanoforests,” Beilstein J. Nanotechnol. 2015, 6, 2463–2469 (2015).

37) L. Adnane, N. Williams, H. Silva and A. Gokirmak, “High temperature setup for measurements of Seebeck coefficient and electrical resistivity of thin films using inductive heating,” Review of Scientific Instruments, vol. 86, pp. 105119 (2015).

36) N. Noor, V. Manthina, K. Cil, L. Adnane, A. G. Agrios, A. Gokirmak, H. Silva, “Atmospheric pressure microplasmas in ZnO nanoforests under high voltage stress,” AIP Advances, 2015, 5, 9, 097212 (2015).

35) S.Muneer, A.Gokirmak, H. Silva, “Vacuum-Insulated Self-Aligned Nanowire Phase-Change Memory Devices,” IEEE Trans. On Electron Devices 62, 5, 1668-1671 (2015).

34) F. Dirisaglik, G. Bakan, Z. Jurado, S. Muneer, M. Akbulut, J. Rarey, L. Sullivan, M. Wennberg, A. King, L. Zhang, R. Nowak, C. Lam, H. Silva and A. Gokirmak, “High speed, high temperature electrical characterization of phase change materials: metastable phases, crystallization dynamics, and resistance drift,” Nanoscale, 2015,7, 16625-16630 (2015).

33) M. B. Akbulut, H. Silva and A. Gokirmak, “3D Computational Analysis of Accumulated Body MOSFETs,” IEEE Trans. Nanotechnology, vol. 14, pp. 1-7 (2015).

32) G. Bakan, A. Gokirmak, H. Silva, “Suppression of thermoelectric Thomson effect in silicon microwires under large electrical bias and implications for phase-change memory devices,” Journal of Applied Physics 116, 23, 234507 (2014).

31) F. Dirisaglik, G. Bakan, A. Faraclas, A. Gokirmak, H. Silva, “Numerical Modeling of Thermoelectric Thomson Effect in Phase Change Memory Bridge Structures,” Intl. Journal of High Speed Electronics and Systems, May 2014 (Special Issue CMOC 2013)

30) A. Faraclas, G. Bakan, L. Adnane, F. Dirisaglik, N. Williams, A. Gokirmak and H. Silva, “Modeling of thermoelectric effects in phase change memory cells,” IEEE Trans. on Electron Devices, 61, 2, 372-387, 10.1109/TED.2013.2296305 (2014).

29) M. Trombetta, N. Williams, S. Fischer, A. Gokirmak, H. Silva, “Finite element electrothermal modeling of nanocrystalline phase-change materials using a mesh-based crystallinity approach,” Electronic Letters 50, 2, pp. 100-101, DOI:  10.1049/el.2013.2253 (2014).

28) G. Bakan, N. Khan, H. Silva, A. Gokirmak, “High-temperature thermoelectric transport at small scales: generation, transport and recombination of minority carriers,” Scientific Reports 3, 2724, doi:10.1038/srep02724 (2013).

27) N. Kan’an, A. Faraclas, N. Williams, H. Silva and A. Gokirmak, “Computational Analysis of Rupture Oxide Phase Change Memory Cells”, IEEE Trans. on Electron Devices, 60, 5, 1649-1655, 10.1109/TED.2013.2255130 (2013).

26) S. Fischer, C. Osorio, N. Williams, S. Ayas, H. Silva, A. Gokirmak, “Percolation transport and filament formation in nanocrystalline silicon nanowires,” Journal of Applied Physics 113, 16, 164902 – 164902-5 (2013).

25) K. Cil, Y. Zhu, J. Li, C. H. Lam, H. Silva, “Assisted cubic to hexagonal phase transition in GeSbTe thin films on silicon nitride,” Thin Solid Films 536, 216–219, http://dx.doi.org/10.1016/j.tsf.2013.03.087 (2013).

24) K. Cil, F. Dirisaglik, M. Wennberg, A. King, A. Faraclas, M. Akbulut, Y. Zhu, C. Lam, A. Gokirmak, H. Silva, “Electrical resistivity of liquid Ge2Sb2Te5 nanostructures,” IEEE Trans. on Electron Devices 60, 1, 433-437 (2013).

23) G. Bakan, L. Adnane, A. Gokirmak, H. Silva, “Extraction of electrical resistivity and thermal conductivity up to melting temperature from self-heated silicon microwires,” Journal of Applied Physics 112, 063527 (2012).

22) N. Williams, H. Silva, A. Gokirmak, “Finite Element Analysis of Scaling of Micro Thermoelectric Generators,” AIP Journal of Renewable and Sustainable Energy 4, 043110 (2012).

21) N. Williams, H. Silva, A. Gokirmak, “Nanoscale ringFETs,” IEEE Electron Device Letters 33, 10, 1339-1341 (2012).

20) A. Cywar, A. Gokirmak, H. Silva, “Finite Element Modeling of a Nanowire-Based Oscillator Achieved Through Solid-Liquid Phase Switching for GHz Operation”, Solid State Electronics 78, 97-101 (2012).

19) A. Cywar, J. Li, C. Lam, H. Silva, “The impact of heater-recess and load matching in phase change memory mushroom cells,” Nanotechnology 23, 22, 225201(2012).

18) M. Staruch, K. Cil, H. Silva, J. Xiong, Q.X. Jia, and M. Jain, “Effect of Mn Doping on the Properties of Sol-gel Derived Pb0.3Sr0.7TiO3 Thin Films,” Integrated Ferroelectrics (special issue, invited)

17) H. Silva, G. Bakan, A. Cywar, N. Williams, N. Henry, F. Dirisaglik, A. Gokirmak, “Crystallization of silicon microstructures through rapid self-heating for high-performance electronics on arbitrary substrates,” Nanoscience and Nanotechnology Letters 4, 962-969 (2012) (special issue, invited)

16) H. Peng, K. Cil, A. Gokirmak, G. Bakan, Y. Zhu, C. Lai, C. Lam and H. Silva, “Thickness dependence of the amorphous-cubic and cubic-hexagonal phase transition temperatures of GeSbTe thin films on silicon nitride,” Thin Solid Films, vol. 520, pp. 2976-2978, 2011.

15) A. Faraclas, N. Williams, A. Gokirmak and H. Silva, Modeling of Set and Reset Operations of Phase-Change Memory Cells, IEEE Electron Device Letters, 32, 12, 1737 – 1739 (2011).

14) A. Cywar, F. Dirisaglik, M. Akbulut, G. Bakan, S. Steen, H. Silva, and A. Gokirmak, “Scaling of silicon phase-change oscillators,” IEEE Electron Device Letters, 32, 11, 1486 – 1488 (2011).

13) G. Bakan, N. Khan, A. Cywar, K. Cil, M. Akbulut, A. Gokirmak and H. Silva, ‘Self-heating of silicon microwires: Crystallization and thermoelectric effects,’ Journal of Materials Research, 26: 1061-1071, Invited Feature Paper (2011).

12) A. Cywar, G. Bakan, H. Silva, A. Gokirmak, “Nanosecond Pulse Generation in a Silicon Microwire,” IEEE Electron Device Letters 31, 12, 1362-1364 (2010).

11) G. Bakan, A. Cywar, H. Silva and A. Gokirmak, “Melting and crystallization of nanocrystalline silicon microwires through rapid self-heating,” Applied Physics Letters, 94, 251910-1 – 251910-3 (2009).

10) A. Cywar, G. Bakan, C. Boztug, H. Silva and A. Gokirmak, “Phase-change oscillations in silicon microwires,” Applied Physics Letters, 94, 072111-1 – 072111-3 (2009).

9) K. M. Fan, C. S. Lai, H. Silva, C. F. Ai and C. R. Chen, “Programming Speed Enhancement by NH Plasma Nitridation of Tunneling Oxide for Ge Nanocrystals Memory,” J. Electrochem. Soc., vol. 155, pp. H889 – H894, (2008).

8) K. J. Lee, R. LaComb, B. Britton, M. Shokooh-Saremi, H. Silva, E. Donkor, Y. Ding and R. Magnusson, “Silicon-Layer Guided-Mode Resonance Polarizer With 40-nm Bandwidth,” IEEE Photonics Technology Letters, vol. 20, 1857-1859 (2008).

7) H. Silva and S. Tiwari, “Random telegraph signal in nanoscale back-side charge trapping memories,” Appl. Phys. Lett., vol. 88, pp. 102105-1 – 102105-3 (2006).

6) H. Silva and S. Tiwari, “A nanoscale memory and transistor using backside trapping,” IEEE Transactions on Nanotechnolog 3, 264-269 (2004).

5) H. Silva, M. K. Kim, U. Avci, A. Kumar and S. Tiwari, “Nonvolatile Silicon Memory at the Nanoscale,” Materials Research Soceity Bulletin, 845-851 (2004).

4) M. K. Kim, S. D. Chae, H. S. Chae, J. H. Kim, Y. S. Jeong, J. W. Lee, H. Silva, S. Tiwari and C. W. Kim, “Ultrashort SONOS Memories,” IEEE Transactions on Nanotechnology 3, 417-424 (2004).

3) S. Tiwari, J. A. Wahl, H. Silva, F. Rana and J. J. Welser, “Small silicon memories: confinement, single-electron,. and interface state considerations,” Applied Physics A, 71, 403-414 (2000).

2) V. Chu, H. Silva, L. M. Redondo, C. Jesus, M. F. Silva, J. C. Soares and J. P. Conde, “Ion implantation of microcrystalline silicon for low process temperature top gate thin film transistors,” Thin Solid Films, vol. 337, pp. 203-207 (1999).

1) V. Chu, J. Jarego, H. Silva, T. Silva, M. Reissner, P. Brogueira and J. P. Conde, “Improved mobility of amorphous silicon thin-film transistors deposited by hot-wire chemical vapor deposition on glass substrates,” Applied Physics Letters, 70, 2714-2716 (1997).