Beyond Moore's Law in opto-electronics: New material enables ultra-fast switching

VO2 is a material known for having a number of outstanding properties that allow it to meet or exceed those of current silicon-based opto-electronics. It is capable of ultrafast switching, low leakage, and is scalable to size-scales smaller than that of conventional silicon, allowing for higher densities of logic and memory elements. Furthermore, as a simple thin-film technology, it is compatible with conventional CMOS processing techniques and can be integrated with existing silicon devices. However, several challenges have kept VO2 away from practical use. First, it has been difficult to make “pure” VO2 because oxides of vanadium end up taking numerous forms (VxOy). Therefore, it has also been difficult to show that the material indeed can be induced via electric fields to exhibit phase transitions (i.e. change in resistance that would enable electronic switches). Professor Ramanathan has overcome these issues. He has developed and demonstrated methods to make thin films of VO2 (the dioxide version, which is the desired oxide version) that are uniform and consistent. Furthermore, Dr. Ramanathan has shown that phase transition (resistance change) can be triggered electrically at room temperature. These inventions and proof of principle pave the way to advanced device configurations to enable a new class of “smart” electronic and optical devices that promise densities and performance unimaginable on conventional silicon wafers in terms of speed, density, and power efficiency.


With device dimensions approaching fundamental physical limits, the semiconductor industry faces a number of challenges to the continued march of Moore’s Law. It is vital to develop new devices and materials to overcome these fundamental limits. Increasingly, “off-roadmap” technologies will become the answer to the questions of tomorrow’s microelectronics industry. With portability becoming a major driver in consumer electronics, there is a strong need for a new class of materials and devices capable of delivering power consumption, speed, and memory capacities that match or exceed the performance of the current state-of-the art.

U.S. Patent(s) Issued: US8864957B2