December 25 2013 Wednesday 15:30
Ali Gökırmak, University of Connecticut
Thermoelectricity at Small Scales & Phase Change Memory

Abstract: Bizarre things happen at small scales. However, the technology that has been driving scaling (CMOS) has been 'business as usual' from the device perspective. The advancements of CMOS processing technologies has enabled scaling to < 20 nm in high-volume manufacturing. The long-anticipated end-of-scaling had ignited research in alternative and complementary technologies. Some of the alternative non-volatile memory technologies are now becoming reality with the ability to scale below 50 nm feature sizes. Phase change memory (PCM) is one of those technologies where the information is stored in the resistive state of the device. The state of the device is reversibly switched by melting and freezing the material in short time durations as current (~1-10 MA/cm2) is passed through them. PCM is in large volume production by Micron as of July 2012. The electro-thermal effects that take place in PCM and other resistive memory (RRAM or memristor) are rather interesting with thermal gradients reaching ~10 K/nm in small volumes and short durations. Fundamental studies in this area are of great interest with a direct impact on the emerging products. This seminar will summarize some of the interesting electro-thermal processes in small scale self-heated structures, the operation of phase change memory devices and their place in the memory hierarchy.

Bio: Ali Gokirmak has received his BS degrees in Electrical Engineering and Physics from University of Maryland at College Park in 1998 and received his PhD in Electrical and Computer Engineering from Cornell University in 2005. He has served as a postdoctoral research associate at Cornell for one year in the same group. He has served as an assistant professor of Electrical & Computer Engineering at University of Connecticut 2006-2013. He is an associate professor in the same department as of 2013. Ali Gokirmak and Helena Silva have established the UConn Nanoelectronics laboratory and are co-directing the research efforts.