The advancements of CMOS processing technologies has enabled
scaling of flash memory to < 20 nm minimum feature sizes, close to the
physical limit of charge based non-volatile storage. There is a growing
industrial interest in non-charge based high-performance non-volatile
memories such as phase change memory (PCM) where the information is stored
in the resistive state of the device. These devices are reversibly switched
between the two states by melting and freezing the material in short time
durations as current (~1-10 MA/cm2) is passed through them. PCM is
commercialized by Micron in July 2012 and is being marketed as a high-speed
non-volatile memory for mobile applications.
PCM is an interesting device for fundamental studies due to extreme thermal
profiles (~10 K/nm) forming in short time-scales in a device geometry that
includes metal-semiconductor junctions. This seminar will summarize where
PCM fits into the memory hierarchy and the interesting electro-thermal
effects that come into play and materials properties and their impact on
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 is an assistant professor of Electrical & Computer
Engineering at University of Connecticut since 2006. Ali Gokirmak and Helena
Silva have established the UConn Nanoelectronics laboratory and are
co-directing the research efforts.
The research efforts in the Nanoelectronics laboratory mainly focus on
fundamental studies and device design through electrical characterization
and computational evaluation of electro-thermal effects and crystallization.
Device fabrication is mostly performed at IBM Watson Research Center
through joint study agreements.
This research portfolio is supported by NSF and US Department of Energy
Office of Basic Energy Sciences (~$1.8M in 2006-2012).