Title :
Electrical and Interfacial Characterization of Atomic Layer Deposited High- κ Gate Dielectrics on GaAs for Advanced CMOS Devices
Author :
Dalapati, Goutam Kumar ; Tong, Yi ; Loh, Wei-Yip ; Mun, Hoe Keat ; Cho, Byung Jin
Author_Institution :
Nat. Univ. of Singapore, Singapore
Abstract :
In this paper, electrical and interfacial properties of MOS capacitors with atomic layer deposited (ALD) Al2O3, HfO2, and HfAlO gate dielectrics on sulfur-passivated (S-passivated) GaAs substrates were investigated. HfAlO on p-type GaAs has shown superior electrical properties over Al2O3 or HfO2 on GaAs, and it is attributed to the reduction of the Ga-O formation at the interfacial layer. HfAlO on p-type GaAs exhibits the best electrical properties after postdeposition annealing (PDA) at 500degC. It is found that PDA, at above 500degC, causes a significant amount of Ga and As out-diffusion into the high-k dielectric, which degrades the interface, as well as bulk high-k properties.
Keywords :
CMOS logic circuits; III-V semiconductors; MOS capacitors; aluminium compounds; atomic layer deposition; gallium arsenide; hafnium compounds; high-k dielectric thin films; passivation; Al2O3 - Interface; GaAs - Surface; HfAlO - Interface; HfO2 - Interface; MOS capacitors; advanced CMOS devices; atomic layer deposition; electrical properties; high-k gate dielectrics; interfacial properties; postdeposition annealing; Annealing; Atomic layer deposition; Degradation; Dielectric devices; Dielectric substrates; Gallium arsenide; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; MOS capacitors; Atomic layer deposition (ALD); GaAs MOS; frequency dispersion; high-$kappa$ dielectric; interface trap; surface passivation; thermal stability;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2007.901261
