Development of a high-speed silicon oxide-based resistive memory technology using a sub-10 nanometer single nanopore. 
Expectations are high for its application to next generation high-performance/high-density non-volatile memory. 

▲ From the left, Gunuk Wang (Professor, Korea University), Soonbang Kwon (Researcher, Korea University), Tae-Wook Kim (Ph.D., Korea Institute of Science and Technology)        

Together, the teams of Professor Gunuk Wang (KU-KIST Graduate School of Converging Science and Technology, Korea University) and Tae-Wook Kim (KIST) developed a resistive memory technology that can significantly improve speed and stability by using a sub-10 nanometer singular nanopore to control nanoscale filaments.   

The research was performed with support from the Ministry of Science and ICT, Korea Research Institute, Samsung Electronics, KU-KIST, and the KIST Young Fellow Program, and was published in the November 28 edition of the renowned scientific journal in the materials/nano sciences field, Nano Letters. 

※ Title of the Article: Controllable Switching Filaments via Tunable and Well-Defined Single Truncated Conical Nanopore Structures for Fast and Scalable SiOX Memory

※ Author Information: Soonbang Kwon (Korea University, Primary Author), Gunuk Wang (Korea University, Corresponding Author), Tae-Wook Kim (Korea Institute of Science and Technology, Corresponding Author), Sukjae Jang (Korea Institute of Science and Technology), Seonghoon Jang (Korea University), Jae-Wan Choi (Korea University), Sanghyeon Choi (Korea University) and seven others.

The D-RAM and S-RAM memory devices in use today are fast, but have volatile characteristics when the power is turned off. Flash memory is non-volatile, but it is slow. Hard disk drives have large capacities, but also have limitations because they require high power usage and are vulnerable to impact. 

The single nanopore SiOx memory technology developed by the research team uses silicon filament phase-change switching at low voltage through the electromigration of the metal wire within a vertical structure. It becomes possible to control the size and position of the filament via the developed single pore structure. This technology is compatible with conventional silicon-based CMOS processing, and because phase changing is maintained, non-volatile characteristics can be obtained. Also, sub-10 nanometer uniform filaments can be formed, nanosecond (<10 ns) operation speed can be achieved, and device uniformity can be improved. As such, this technology is could be applied as next generation high-speed, low-power memory. Related patents have been already filed. 

Terminology:
1. Silicon
◯ Silicon is one of the world’s most abundant materials and can be obtained easily and inexpensively. The energy volume between bands is higher than that of Germanium making it advantageous in manufacturing devices that operate at high temperatures. With various other advantages, most of the semiconductor integrated circuits manufactured today are manufactured using silicon. One of the common silicon oxides is the high-quality insulator film, silicon dioxide (SiO2).
2. Resistive Switching Memory
◯ A type of next generation, non-volatile memory which benefits from the phenomena of reduced resistance when a pathway through which current flows is created in the case where a high enough voltage is applied to an insulator material. Once a pathway is created, it can be easily removed or re-created by applying a moderate amount of voltage. It can be developed using materials such as perovskite, transition metal oxide, and chalcogenide. 
3. Non-Volatile Memory
◯ Non-volatile memory (NVM) is a type of computer memory that can continuously maintain the stored information even without a power supply. Types of non-volatile memory include ROM, flash memory, computer magnetic storage devices, and optical disk drives. 

Figure Description:

Figure 1: Schematic diagram and heat treatment-based depth analysis of the nanopore oxide memory device. The heat treatment penetrates the oxide, and the formed nanopore is used to develop the memory device. 

Figure 2: Measurement experiment results of the nanopore oxide memory device. 
(a) Formation of relatively small amount of breakdown voltage, (b) Storing and deleting possible with even a small number of nanosecond signal switches, (c) Characteristics of the nanopore oxide memory device’s current-voltage.