Steven Koester

Professor Steven Koester

Steven Koester

Russell J. Penrose Professor in Nanotechnology, Department of Electrical and Computer Engineering


Kenneth H. Keller Hall
Room 5-153
200 Union Street Se
Minneapolis, MN 55455


Ph.D., Electrical & Computer Engineering, 1995, University of California, Santa Barbara, CA, USA
M.S., Electrical Engineering, 1991, University of Notre Dame, Notre Dame, IN, USA
B.S., Electrical Engineering, 1989, University of Notre Dame, Notre Dame, IN, USA

Professional Background

Micro- and nanoelectronics optoelectronic devices, photovoltaics, energy harvesting, biomedical devices

Research Interests

Koester Research Group Site

My research goal is to develop semiconductor device solutions to address the worldwide energy crisis, and to explore new applications for semiconductor and solid-state  devices.

On the demand-side of the energy crisis, computational systems now use a significant fraction of the world-wide energy supply, and the demand for computational resources continues to increase rapidly. To address this problem, I am studying novel steep-subthreshold-slope transistors that could dramatically improve the efficiency of binary logic operations compared to conventional MOSFETs. I am also interested in photonic interconnects and customized hybrid Si/III-V 3D integrated systems that could reduce the power consumed in the communication subsystem of computers by orders of magnitude.

I am also interested in addressing the supply side of the energy problem by exploring green power generation technology, particularly solar cells. Nanowire-based photovoltaic systems are particularly interesting in that they have the potential to overcome the cost/efficiency conundrum of current solar cell technology. Devices and systems that can directly convert ambient (optical, vibrational, thermal) energy into electricity are also interesting, as they could enable new application areas by allowing computational systems access to new environments, particularly ones where supplying power from the grid or batteries is not practical. Such applications include remote sensing systems and in vivo biomedical devices.

Teaching Subjects
EE 8950 Advanced Semiconductor Transistors
EE 5163 Semiconductor Properties and Devices I
EE 4951 Senior Design Project
EE 3161 Semiconductor Devices
EE 3101 Circuits and Electronics Lab I

Honors and Awards

2022 Optica (formerly OSA) Fellow for technical innovations in emerging optoelectronic devices, particularly those involving group-IV and 2D-material-based photodetectors and optical modulators
2017 IEEE Fellow for contributions to group-IV electronic and photonic devices
2009 Keynote Speaker at 4th International Microsystems, Packaging, Assembly and Circuits Technology Conference (IMPACT 2009)
2006-2009 Device Research Conference Technical Program Committee, 2009 Conference General Chair
Served on numerous conference organizing/technical program committees
10 IBM Patent Plateau Awards 

Selected Publications

L. Chang, D. J. Frank, R. Montoye, S. J. Koester, B. Ji, P. Coteus, R. Dennard, and W. Haensch, “Practical strategies for power-efficient computing technologies,” to be published in Proc. IEEE 98, 2010.

S. O. Koswatta, S. J. Koester, and W. Haensch, “1D broken-gap tunnel transistor with MOSFET-like on-currents and sub-60mV/dec subthreshold swing,” Proceedings of the 2009 International Electron Devices Meeting, Baltimore, MD, Dec. 14-16, 2009.

D. Kim, Y. Lee, D. Sylvester, D. Blaauw, Y. Lee, J. Cai, I. Lauer, L. Chang and S. J. Koester, “Heterojunction tunneling transistor (HETT)-based extremely low power applications,” 2009 International Symposium on Low Power Electronics and Design (ISLPED), San Francisco, CA, Aug. 19-21, 2009.

S. J. Koester, A. M. Young, R. R. Yu, S. Purushothaman, K. N. Chen, D. C. La Tulipe, N. Rana, L. Shi, M. R. Wordeman, and E. J. Sprogis, “Wafer-level three-dimensional integration technology,” IBM J. Res. Dev. 52, 583-98 (2008).

F. Liu, R. R. Yu, A. M. Young, J. P. Doyle, X. Wang, L. Shi, K.-N. Chen, X. Li, D. A. Dipaola, D. Brown, C. T. Ryan, J. A.Hagan, K. H. Wong, M. Lu, X. Gu, N. R. Klymko, E. D. Perfecto, A. G. Merryman, K. A. Kelly, S. Purushothaman,S. J. Koester, R. Wisnieff, and W. Haensch, “A 300-mm wafer-level three-dimensional integration scheme using tungsten through-silicon via and hybrid Cu-adhesive bonding,” IEDM Tech. Digest, 599-602 (2008), Proceedings of the 2008 International Electron Devices Meeting, San Francisco, CA, Dec. 15-17, 2008.

S. W. Bedell, A. Majumdar, J. A. Ott, J. Arnold, K. Fogel, S. J. Koester, and D. K. Sadana, “Mobility scaling in short-channel length strained Ge-on-insulator P-MOSFETs,” IEEE Elect. Dev. Lett. 29, 811-3 (2008).

Y. Sun, E. W. Kiewra, S. J. Koester, N. Ruiz, A. Callegari, K. E. Fogel, D. K. Sadana, J. Fompeyrine, D. J. Webb, J.-P.Locquet, M. Sousa, R. Germann, K. T. Shiu, and S. R. Forrest, “Enhancement-mode buried-channel In0.7 Ga0.3 As/In0.52 Al0.48 As MOSFETs with high-k gate dielectrics,” IEEE Elect. Dev. Lett. 28, 473-5 (2007).

S. J. Koester, C. L. Schow, L. Schares, G. Dehlinger, J. D. Schaub, F. E. Doany, and R. A. John, “Ge-on-SOI-detector/Si-CMOS-amplifier receivers for high-performance optical communications applications,” IEEE J. Lightwave Tech. 25, 46-57(2007).

S. J. Koester, J. D. Schaub, G. Dehlinger, and J. O. Chu, “Ge-on-SOI infrared detectors for integrated photonic applications,”IEEE J. Sel. Top. Quant. Electron. 12, 1489-1502 (2006).

S. J. Koester, E. W. Kiewra, Y. Sun, D. A. Neumayer, J. A. Ott, M. Copel, D. K. Sadana, D. J. Webb, J. Fompeyrine, J.-P. Locquet, C. Marchiori, M. Sousa, and R. Germann, “Evidence of electron and hole inversion in GaAs MOS capacitors with HfO2 gate dielectrics and a-Si/SiO2 interlayers, ” Appl. Phys. Lett. 89, 042104-1-3 (2006).

S. J. Koester, K. L. Saenger, J. O. Chu, Q. C. Ouyang, J. A. Ott, K. A. Jenkins, D. F. Canaperi, J. A. Tornello, C. V.Jahnes, and S. E. Steen, “Laterally-scaled Si/Si0.7 Ge0.3 n-MODFETs with fmax > 200 GHz and low operating bias,” IEEE Elect. Dev. Lett. 26, 178-80 (2005).

K. Rim, S. Koester, M. Hargrove, J. Chu, P. M. Mooney, J. Ott, T. Kanarsky, P. Ronsheim, M. Ieong, A. Grill, and H.-S. P.Wong, “Strained Si NMOSFETs for high performance CMOS technology,” Proceedings of the 2001 Symposium on VLSI Technology, Kyoto, Japan, Jun. 12-14, 2001.

Google Scholar Page