Sundar Gopalan received his Bachelor of Technology degree from the Institute of Technology, Banaras Hindu University, Varanasi, India, in May 1995. He completed his M.S. and Ph.D. degrees from the University of Texas at Austin, USA in the area of Microelectronic Engineering in 2002. He worked in International Sematech, a semiconductor research consortium located in Austin, Texas, USA, as a Post-Doc and Process research engineer for two years in the Advanced Gate Stack Engineering Group. There he was involved in studying and designing new gate stack structures for the next generation CMOS Technology. He joined the Department of Electronics and Communication Engineering at Amrita School of Engineering, Amritapuri Campus, India, in August of 2004. He has been the Chairman and Associate Professor in the same department since May of 2010. He has authored/co-authored more than 42 International publications. He specializes in the areas of Electronic Materials, Semiconductor Devices, VLSI Fabrication, Materials Characterization, Processing and Mechanical Behavior of Materials.

Publications

Publication Type: Journal Article
Year of Conference Publication Type Title
2014 Journal Article S. Ramesh, Dutta, S., Shankar, B., and Gopalan, S., “Identification of current transport mechanism in Al2O3 thin films for memory applications”, Applied Nanoscience, vol. 5, pp. 115-123, 2014.[Abstract]

The effect of oxygen anneal on the electrical characteristics, especially on the current transport mechanism, of Al2O3 films in the thickness range of 10–30 nm was examined in detail. The analyses were performed at electric fields of ≤2.5 MV/cm to effectively address the reliability of Al2O3-based devices operating in the low electric field regime. The general conduction mechanism equations were used to simulate the expected current density (J) values for a given electric field (E) range. The characteristic linear plots of the conduction mechanisms were then used to compare the experimental and simulated data to identify the most probable mechanism occurring in the dielectric. Parameters like barrier height and activation energy were extracted from the fit. It was found that oxygen anneal has profound effects on the electrical properties of Al2O3 films, with annealed films demonstrating a different conduction mechanism than their unannealed counterparts, along with significant improvement in the leakage current and barrier height. This kind of analyses will help optimize the process conditions for Al2O3 deposition and provide an optimal range for device operation, thus improving the reliability of Al2O3 films for applications in CMOS logic and Flash memory.

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2012 Journal Article S. Dutta, Ramesh, S., Shankar, B., and Gopalan, S., “Effect of PVD process parameters on the quality and reliability of thin (10–30 nm) Al2O3 dielectrics”, Applied Nanoscience, vol. 2, pp. 1–6, 2012.
2011 Journal Article N. Alex Jacob, Pillai, V., Nair, S., Harrell, D. Toshio, Delhommer, R., Chen, B., Sanchez, I., Almstrum, V., and Gopalan, S., “Low-Cost Remote Patient Monitoring System Based on Reduced Platform Computer Technology”, Telemedicine and e-Health, vol. 17, pp. 536–545, 2011.[Abstract]

Telemedicine is a well-accepted method providing healthcare benefits to people over long distances. However, in normal telemedicine practices, dedicated complex hardware and network backbones for data collection and communication make the system unintelligible to the common man. Centralization of telemedicine units also makes it accessible only to the immediate surrounding community. In an attempt to address these issues, a study aimed at developing a low-cost remote patient monitoring (RPM) system based on reduced platform computer technology has been carried out. The main focus of the work was to develop a real-time, universal serial bus plug-in module for a portable RPM system, specifically the XO Laptop. In addition, this system is also intended to serve as an educational tool especially for the One Laptop per Child target community. This article discusses data collection, preprocessing, and constraints such as network bandwidth and power availability prior to data transmission over a user datagram protocol (UDP)-based network. More »»
2011 Journal Article N. A. Jacob, Pillai, V., Nair, S., ,, Harrell, D. T., Delhommer, R., Chen, B., Sanchez, I., Almstrum, V., and Gopalan, S., “Low-cost remote patient monitoring system based on reduced platform computer technology.”, Telemedicine journal and e-health : the official journal of the American Telemedicine Association, vol. 17, pp. 536-545, 2011.[Abstract]

Telemedicine is a well-accepted method providing healthcare benefits to people over long distances. However, in normal telemedicine practices, dedicated complex hardware and network backbones for data collection and communication make the system unintelligible to the common man. Centralization of telemedicine units also makes it accessible only to the immediate surrounding community. In an attempt to address these issues, a study aimed at developing a low-cost remote patient monitoring (RPM) system based on reduced platform computer technology has been carried out. The main focus of the work was to develop a real-time, universal serial bus plug-in module for a portable RPM system, specifically the XO Laptop. In addition, this system is also intended to serve as an educational tool especially for the One Laptop per Child target community. This article discusses data collection, preprocessing, and constraints such as network bandwidth and power availability prior to data transmission over a user datagram protocol (UDP)-based network. More »»
2004 Journal Article J. J. Peterson, Young, C. D., Barnett, J., Gopalan, S., Gutt, J., Lee, C. - H., Li, H. - J., Hou, T. - H., Kim, Y., Lim, C., and , “Subnanometer scaling of HfO2/metal electrode gate stacks”, Electrochemical and solid-state letters, vol. 7, pp. G164–G167, 2004.[Abstract]

The equivalent oxide thickness (EOT) of high-k n-channel metal oxide semiconductor (NMOS) transistors was scaled using 3 methods, Formula reduction of the bottom interfacial layer (BIL) using Formula interface engineering, Formula thickness reduction of the Formula dielectric, and Formula use of metal gate electrodes to minimize top interfacial growth formation and polysilicon depletion. NMOS transistors fabricated using these methods demonstrate 0.72 nm EOT using the Formula BIL with scaled Formula /metal gates and 0.81 nm EOT using the Formula BIL with scaled Formula /metal gates. Charge pumping, mobility, and device performance results of these high-k NMOS transistors is discussed. © 2004 The Electrochemical Society. All rights reserved. More »»
2003 Journal Article K. Onishi, Kang, C. Seok, Choi, R., Cho, H. - J., Gopalan, S., Nieh, R. E., Krishnan, S. A., and Lee, J. C., “Improvement of surface carrier mobility of HfO 2 MOSFETs by high-temperature forming gas annealing”, Electron Devices, IEEE Transactions on, vol. 50, pp. 384–390, 2003.
2003 Journal Article M. Shahariar Akbar, Gopalan, S., Cho, H. - J., Onishi, K., Choi, R., Nieh, R., Kang, C. S., Kim, Y. H., Han, J., Krishnan, S., and , “High-performance TaN/HfSiON/Si metal-oxide-semiconductor structures prepared by NH 3 post-deposition anneal”, Applied physics letters, vol. 82, pp. 1757–1759, 2003.
2002 Journal Article H. - J. Cho, Kang, C. Seok, Onishi, K., Gopalan, S., Nieh, R., Choi, R., Krishnan, S., and Lee, J. C., “Structural and electrical properties of HfO 2 with top nitrogen incorporated layer”, Electron Device Letters, IEEE, vol. 23, pp. 249–251, 2002.
2002 Journal Article S. Gopalan, Onishi, K., Nieh, R., Kang, C. S., Choi, R., Cho, H. - J., Krishnan, S., and Lee, J. C., “Electrical and physical characteristics of ultrathin hafnium silicate films with polycrystalline silicon and TaN gates”, Applied physics letters, vol. 80, pp. 4416–4418, 2002.
2000 Journal Article S. Gopalan, Balu, V., Lee, J. - H., Hee-Han, J., and Lee, J. C., “Study of the electronic conduction mechanism in Nb-doped SrTiO3 thin films with Ir and Pt electrodes”, Applied Physics Letters, vol. 77, pp. 1526–1528, 2000.
2000 Journal Article A. Lucas, Gopalan, S., Lee, J. C., Kaushal, S., Niino, R., and Tada, Y., “Ultrathin Gate Oxynitrides Grown Using Fast Ramp Vertical Furnace for Sub-130 Nanometer Technology”, Electrochemical and Solid-State Letters, vol. 3, pp. 389–391, 2000.
2000 Journal Article L. Kang, Lee, B. Hun, Qi, W. - J., Jeon, Y., Nieh, R., Gopalan, S., Onishi, K., and Lee, J. C., “Electrical characteristics of highly reliable ultrathin hafnium oxide gate dielectric”, Electron Device Letters, IEEE, vol. 21, pp. 181–183, 2000.
1999 Journal Article S. Gopalan, Wong, C. - H., Balu, V., Lee, J. - H., Han, J. H., Mohammedali, R., and Lee, J. C., “Effect of niobium doping on the microstructure and electrical properties of strontium titanate thin films for semiconductor memory application”, Applied physics letters, vol. 75, pp. 2123–2125, 1999.
Publication Type: Conference Paper
Year of Conference Publication Type Title
2011 Conference Paper S. Gopalan, Dharmarajan, E., Nieh, R., Onishi, K., Kang, C. S., Choi, R., Cho, H., and Lee, J. C., “Ultrathin Hafnium Silicate Films with TaN and Polysilicon Gate Electrodes for Gate Dielectric Application”, in IEEE Semiconductor Interface Specialist Conference, Washington DC, 2011.
2004 Conference Paper G. Bersuker, Gutt, J., Chaudhary, N., Moumen, N., Lee, B. H., Barnett, J., Gopalan, S., Brown, G., Kim, Y., Young, C. D., and , “Integration issues of high-k gate stack: Process-induced charging”, in Reliability Physics Symposium Proceedings, 2004. 42nd Annual. 2004 IEEE International, 2004.[Abstract]

Electrical properties of a wide range of Hf-based gate stacks were investigated using several modifications of a standard planar CMOS process flow to address the effects of transistor processing on the electrical properties of the high-k dielectrics. Characteristics of the short channel transistors were shown to be very sensitive to the fabrication process specifics - process sequence, tools, and recipes. It was concluded that, contrary to SiO2, the high-k films could be contaminated with reactive species during the post-gate definition fabrication steps, resulting in the formation of local charge centers. Such process-induced charging (PIC) degrades transistor performance and complicates evaluation of the intrinsic properties of high-k dielectrics. A process scheme that minimizes PIC is discussed. More »»
2003 Conference Paper M. I. Gardner, Gopalan, S., Gutt, J., Peterson, J., Li, H. - J., and Huff, H. R., “EOT scaling and device issues for high-k gate dielectrics”, in Gate Insulator, 2003. IWGI 2003. Extended Abstracts of International Workshop on, 2003.
2002 Conference Paper R. Choi, Onishi, K., Kang, C. Seok, Gopalan, S., Nieh, R., Kim, Y. H., Han, J. H., Krishnan, S., Cho, H. - J., Shahriar, A., and , “Fabrication of high quality ultra-thin HfO/sub 2/gate dielectric MOSFETs using deuterium anneal”, in Electron Devices Meeting, 2002. IEDM'02. International, 2002.
2002 Conference Paper K. Onishi, Kang, C. Seok, Choi, R., Cho, H. - J., Gopalan, S., Nieh, R., Krishnan, S., and Lee, J. C., “Effects of high-temperature forming gas anneal on HfO/sub 2/MOSFET performance”, in VLSI Technology, 2002. Digest of Technical Papers. 2002 Symposium on, 2002.
2000 Conference Paper B. Hun Lee, Choi, R., Kang, L., Gopalan, S., Nieh, R., Onishi, K., Jeon, Y., Qi, W. - J., Kang, C., and Lee, J. C., “Characteristics of TaN gate MOSFET with ultrathin hafnium oxide (8/spl Aring/-12/spl Aring/)”, in Electron Devices Meeting, 2000. IEDM'00. Technical Digest. International, 2000.
Publication Type: Conference Proceedings
Year of Conference Publication Type Title
1999 Conference Proceedings S. Gopalan, Han, J. H., Balu, V., Lee, J. H., Mohemmedali, R., Wong, C. H., and Lee, J. C., “Effect of N2O on the RF-magnetron Sputtered SrTiO3 Films for ULSI DRAM Application”, Proceedings of the 11th International Symposium on Integrated Ferroelectrics. Colorado Springs, 1999.
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Faculty Email: 
sundar@am.amrita.edu