Doctoral defence: Joonas Merisalu “Resistive switching in memristor structures with multilayer dielectrics”

On 27 August at 13:15, Joonas Merisalu will defend his doctoral thesis “Resistive switching in memristor structures with multilayer dielectrics” for obtaining the degree of Doctor of Philosophy (Physical Engineering).

Supervisiors: 
Professor emeritus Jaan Aarik, University of Tartu
Professor Kaupo Kukli, University of Tartu
Associate Professor Aile Tamm, University of Tartu

Opponent:
Dr. Robert Zierold, University of Hamburg, Center for Hybrid Nanostructures (Germany)

Summary: 
In the last decades electronics and computer systems have undergone tremendous development. A room-size computer has become a smart device that replaces a wristwatch. This progress has been enabled by rapid application of scientific research results. For example, the random-access memory of a computer that enables fast data exchange, as well as flash memory in data storage devices, is based on the retention of electrical charge. These technologies essentially originate from 1960-s and 1970-s, but the availability of an immensely large memory capacity has been ensured by reducing the physical dimensions of memory cells, which has been due to the research and development in materials science. Unfortunately, recent studies show that further increment of memory capacity is becoming more complex, time-consuming, and expensive. Thus, scientists have increasingly turned their attention to the development of new memory technologies. Resistive switching memory, a memristor, is one of these emerging memory technologies that relies on the changing the resistance of a material instead of retaining electrical charge. The fact that this phenomenon occurs in the nanoworld, allowing the creation of electronic memories with even smaller dimensions and greater capacity deserves particular attention. Since the resistive switching takes place in nano-dimensional environments, understanding the mechanisms, controlling, and investigations are still extremely complicated. Even though the semiconductor industry is already producing resistive switching memories, the large-scale application of this technology still requires extensive research. In the course of this work, memristor structures composed of materials used in today's computer chips were fabricated and characterized, and their suitability for use in next-generation memory devices was studied. As a result, it was shown how the careful combination of materials permits to vary and optimize different parameters of memristors.

Defence can be followed in Zoom: https://ut-ee.zoom.us/j/9530588152?pwd=ZzgzMjY4YytzUkZ5aVRCd2pOdVNQQT09 (meeting ID: 953 058 8152, passcode: kaitsmine).