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Impact of thermal oxidation pressure and temperature on deactivation of the interfacial trap states in Al 2 O 3 /GaAs MOS capacitor
Author(s) -
Lim Hajin,
Kim Seongkyung,
Kim Joon Rae,
Song Ji Hun,
Lee NaeIn,
Jeong Jae Kyeong,
Kim Hyeong Joon
Publication year - 2015
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201532184
Subject(s) - stack (abstract data type) , thermal oxidation , materials science , etching (microfabrication) , thermal , dispersion (optics) , trap (plumbing) , capacitor , layer (electronics) , penning trap , analytical chemistry (journal) , optoelectronics , chemistry , composite material , electrical engineering , thermodynamics , voltage , optics , ion , physics , organic chemistry , chromatography , environmental engineering , computer science , programming language , engineering
Although GaAs is one of the most attractive channel materials for achieving high electron mobility, reduction of the interface state is still required for high quality MOS devices. In this paper, thermal oxidation under two pressures and various temperatures, and subsequent HF etching were performed to deactivate the interfacial states of the Al 2 O 3 /GaAs stack. High pressure oxidation (HPO) at 10 atm and 400 °C resulted in substantial improvement in the C – V frequency dispersion characteristics whereas the deactivation effect of the interfacial trap density under the thermal oxidations at 1 atm was not observed irrespective of the thermal oxidation temperature, ranging from 400 to 550 °C. Strong disparity between pressure and temperature was elucidated based on the existence of an efficient As excess layer and the prevention of unwanted Ga oxidation.