Thermal stability of HfO2 high-k gate dielectric on GaAs is investigated. Compared to HfO2 gate dielectric, significant improvements in interfacial properties as well as electrical characteristics were found by constructing a Al2 O3 / HfO2 / Al2 O3 dielectric stack. At elevated temperatures, the amorphous Al2 O3 layers were effective in inhibiting crystallization of HfO2. Since the passivating Al2 O 3 layers prevent interfacial oxide and trap charge formation, it aids in reducing the increasing rate of equivalent oxide thickness as well as capacitance-voltage hysteresis. Transmission electron microscopy and x-ray photoelectron spectroscopy data supported the improved electrical characteristic of GaAs metal-oxide-semiconductor capacitors with Al2 O3 / HfO2 / Al2 O3 gate dielectric stack.
Bibliographical noteFunding Information:
This work was financially supported by a grant from the “Next-generation Substrate technology for high performance semiconductor devices (Grant No. KI002083)” of the Ministry of Knowledge Economy (MKE) of Korea and the Joint Program for Samsung Electronics–Yonsei University.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)