RRAM mechanism in HfO2-based devices

 

Speaker: Gennadi Bersuker (SEMATECH)

Time and Date: 10:00-11:00, March 19, 2013

Place: Room 389, Microelectronics Building, Zhangjiang Campus

Abstract

Resistive random access memory (RRAM) devices utilizing a filamentary conduction mechanism have attracted significant attention due to their unique scalability, low energy consumption and short characteristic switching times. While RRAM devices fabricated using a variety of dielectric materials exhibit electrically similar switching features, the underlying mechanisms can be very material-specific and might involve diffusion of oxygen or oxygen vacancies or metal ions, as well as material phase change.  In the case of RRAM devices fabricated using fab-friendly TiN and HfO2-based materials, electrical properties of the conductive paths were successfully simulated using the characteristics of electrically-active structural defects as obtained by the ab initio calculations. Processes responsible for the forming operation were modeled invoking breakage of the O-Hf bonds and subsequent diffusion of the released oxygen ions out of the filament region. Modeling switching processes based on the obtained characteristics of the conductive filament and oxygen ions distribution in the surrounding oxide allows identifying the operational conditions favoring formation of resistive states of lower operation currents.

 

 

Biography

Gennadi Bersuker completed his M.S. and Ph.D. in Physics at the Leningrad State University and Kishinev State University, respectively. After graduation, he joined Moldavian Academy of Sciences, and then worked at Leiden University and the University of Texas at Austin. Since 1994, he has been working at SEMATECH on electrical characterization of Cu/low-k interconnect, high-k gate stacks, advanced memory, and III-V logic devices. He is the Chair of IEEE Reliability Physics committee, an Editor of IEEE Transactions on Device Materials and Reliability and has been involved in organizing, chairing, or serving as a committee member in a number of technical conferences, including IRW, IRPS, IEDM, APS, etc. He is a SEMATECH Fellow and has published over 250 papers on the electronic properties of dielectrics and semiconductor processing and reliability.