Development of High-k Dielectric for Antimonides and a sub 350 degree Celsius III-V pMOSFET Outperforming Germanium

摘要

In(sub x)Ga(sub 1-x)Sb channel materials have the highest hole and electron mobility among all III-V semiconductors, high conduction and valence band offsets (CBO/VBO) with lattice matched Al(sub x)In(sub 1-x)Sb for heterostructure MOSFET design and allow low thermal budget MOSFET fabrication. While buried channel HEMT-like devices with excellent electron and hole transport have been demonstrated, realization of an Sb-channel MOSFET has remained elusive due to the highly reactive nature of the Sb-surface. In this paper we overcome these challenges and fabricate an In(sub x)Ga(sub 1-x)Sb pMOSFET with high hole mobility: a bottleneck for III-V complimentary logic. Synchrotron Radiation Photoemission Spectroscopy (SRPES) is used to aid the development of ALD Al2O3 on GaSb with a mid bandgap Dit of 3 x 10(to the 11th power)/cm2eV-1. A p+/n diode with ideality factor of 1.4 and I(sub ON)/I(sub OFF) > 5 x 10(to the 4th power) is developed. pMOSFETs with various channel configurations to optimize the hole transport are fabricated using a sub 350 degrees Celsius gate-first process. Surface (buried) channel pMOSFETs with peak hole mobility of 620 (910) cm2/Vs and having more than 50 (100)% higher mobility than Germanium over the entire sheet charge range are demonstrated and analyzed.