Integration of high-κ dielectrics on epitaxial (100), (110) and (111) Germanium for Multifunctional Devices

With continued scaling of Si CMOS technology, new channel materials and device architectures are needed to address power consumption and constrained high-speed operation. With the demonstration of n-channel III-V transistors, the development of equivalent p-channel transistor is mandatory to realize energy-efficient CMOS logic. The bulk transport properties of Ge make it an ideal candidate for p-channel transistor. The ultra-high hole mobility Ge can be realized through a III-V/Ge/III-V transistor configuration with different surface orientations would enable much faster switching, thus addressing dynamic power consumption, while the superior high-gate dielectric and larger bandgap barrier would help minimize OFF-state leakage. This paper discusses the i) in-situ growth of III-V/Ge/III-V heterostructure, ii) tailor-made surface orientations of Ge enable to achieve both high-hole and high-electron mobilities, and iii) band offsets of high-κ dielectrics on crystallographic oriented epitaxial (100)Ge, (110)Ge, and (111)Ge layers using solid state molecular beam epitaxy.