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Effects of Y incorporation in TaON gate dielectric on electrical performance of GaAs metal–oxide–semiconductor capacitor
Author(s) -
Liu Li Ning,
Choi Hoi Wai,
Xu Jing Ping,
Lai Pui To
Publication year - 2016
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201600227
Subject(s) - materials science , dielectric , capacitor , gate dielectric , capacitance , passivation , metal gate , optoelectronics , oxide , semiconductor , gate oxide , high κ dielectric , voltage , analytical chemistry (journal) , electrical engineering , electrode , nanotechnology , transistor , chemistry , layer (electronics) , metallurgy , engineering , chromatography
In this study, GaAs metal–oxide–semiconductor (MOS) capacitors using Y‐incorporated TaON as gate dielectric have been investigated. Experimental results show that the sample with a Y/(Y + Ta) atomic ratio of 27.6% exhibits the best device characteristics: high k value (22.9), low interfacestate density (9.0 × 10 11 cm –2 eV –1 ), small flatband voltage (1.05 V), small frequency dispersion and low gate leakage current (1.3 × 10 –5 A/cm 2 at V fb + 1 V). These merits should be attributed to the complementary properties of Y 2 O 3 and Ta 2 O 5 :Y can effectively passivate the large amount of oxygen vacancies in Ta 2 O 5 , while the positively‐charged oxygen vacancies in Ta 2 O 5 are capable of neutralizing the effects of the negative oxide charges in Y 2 O 3 . This work demonstrates that an appropriate doping of Y content in TaON gate dielectric can effectively improve the electrical performance for GaAs MOS devices.Capacitance–voltage characteristic of the GaAs MOS capacitor with TaYON gate dielectric (Y content = 27.6%) proposed in this work with the cross sectional structure and dielectric surface morphology as insets.