SPP 2477: Nitrides4Future - Novel Materials and Device Concepts

Basic data for this project

Description

Semiconductors are the backbone of modern microelectronics – a key technology for driving innovations. Besides silicon, gallium nitride has been established as reliable platform. The high potential of the material class of nitrides stems from the extraordinarily broad spectrum of material properties: semiconducting, metallic, piezoelectric, ferroelectric or superconducting. Nitride semiconductors are already used commercially in photonic devices such as LEDs and laser diodes as well as in high-frequency and power electronic devices. However, this should not obscure the fact that further development of nitride technology is still strongly limited by the properties of the materials mostly investigated so far. For instance, the efficiency of UVC LEDs is still very low because the defect densities typical of nitrides have a much stronger effect in UVC LEDs than in blue LEDs. For power electronic devices, approaches for realizing vertical device architectures for higher breakdown voltage, higher currents, or normally-off transistors are being studied. However, piezoelectric and ferroelectric properties of some of the new metal nitrides have not been applied at all in device architectures. This could be a very exciting approach, e.g. for the realization of ferroelectric memories and in combination with photonic devices for optical neuromorphic computing. Furthermore, they have enormous potential as piezoelectric acoustic filters in communication electronics. There is also growing evidence that several ternary metal nitrides (beyond the best known representative AlScN) possess highest electro-optic coefficients. Such materials are being considered as promising substitutes for LiNbO3 and could pave the way for a future technology for fabricating photonic circuits for the blue/UV spectral region. Each of the described functionalities are attractive in their own right. However, the combination of the functionalities in one device holds particularly great potential for a disruptive evolution of nitride technology. The potential combination of photonic, electronic, ferroelectric, and electro-optic properties in a single material family is unique. The goal of the priority program is to explore and systematically improve the properties of novel nitrides (such as alloys of AlN with CrN, YN, LaN, YbN, and MoN), and to subsequently realize device architectures that exploit the multitude of functionalities.