Professor Jae-Hyung Jang's research team develops self-rectifying memory

□ A solution process-based self-rectifying resistance-change memory * device has been developed to enable highly integrated, high-speed memory implementation. Professor Jae-Hyung Jang of the School of Electrical Engineering and Computer Science at the Gwangju Institute of Science and Technology (GIST, President Seung Hyeon Moon) said, "We have developed a high-performance, self-rectifying resistance-change memory * device technology that has 25 times the resistance switching ratio * compared to the conventional solution process-based self-rectifying resistance change memory with 100 times the self-rectification ratio. * "

* Self-rectifying resistance change memory: This is a method to solve the interference phenomenon between adjacent cells that occurs when a resistance change memory cell device is applied to the crossbar array structure.

* Self-rectification ratio is the ratio of the on-resistance at the reverse bias to the on-resistance at the forward bias.

□ The researchers developed a self-rectifying resistance memory device using a solution process based on iron oxide-oxidized graphene hybrid * thin film layer that has a self-rectification ratio of 10,000 times or more, which is 100 times higher than a conventional solution process self-rectifying memory device. The resistance switching ratio of this device is more than 10,000 times, which is 25 times higher than existing devices.

 

* Iron oxide-oxidized graphene hybrid: A hybrid thin-film layer with a structure in which iron oxide nanoparticles are embedded on the oxidized graphene thin film.

□ The researchers found that the ferroelectric-oxide graphene hybrid thin-film layer and the silicon nitride thin-film layer in the device exhibit a uniform and stable resistance switching behavior depending on the polarity and size of the applied voltage. By using upper and lower electrodes with different functions and by inserting a silicon nitride insulator between the solution process iron oxide-oxidized graphene hybrid thin film layer and the lower electrode, a asymmetric tunneling barrier * is created in the silicon nitride according to the polarity of the applied voltage.

* Tunneling barrier: The energy barrier that particles face in quantum mechanics when exiting with a probability higher than the kinetic energy of particles.

□ Professor Jae-Hyung Jang said, "This research has developed a solution process memory device technology capable of simultaneous resistance switching and rectification functions. A simple device structure has been proposed to greatly simplify the architecture and manufacturing process of the crossbar array. It is expected to be applicable to highly integrated, high-speed semiconductor logic and flexible memory systems in the future. "

□ This reseaerch was supported by the GIST Research Institute Project through a grant provided by GIST in 2017, by the Technology Innovation Program funded by the Ministry of Trade, Industry & Energy of Korea, and by the National Research Foundation of Korea grant funded by the Ministry of Science, ICT and Future Planning of Korea government. The paper was published as the front cover of Nanoscale on August 18, 2017: "Self-rectifying bipolar resistive switching memory based on an iron oxide and graphene oxide hybrid."