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ZnO TFTs prepared by chemical bath deposition technique with high‐ k La 2 O 3 gate dielectric annealed in ambient atmosphere
Author(s) -
Gogoi Paragjyoti,
Saikia Rajib,
Saikia Dipok,
Dutta Ronen Prakash,
Changmai Sanjib
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.201431605
Subject(s) - thin film transistor , materials science , dielectric , gate dielectric , optoelectronics , torr , electrode , threshold voltage , high κ dielectric , gate oxide , field effect , transistor , analytical chemistry (journal) , electrical engineering , voltage , nanotechnology , chemistry , layer (electronics) , physics , engineering , thermodynamics , chromatography
In this paper, the electrical properties of top‐gated thin‐film transistors with low‐cost chemical bath deposition (CBD) of ZnO as active material and a high‐ k rare‐earth oxide La 2 O 3 as gate dielectric have been reported. The source‐drain and gate electrodes and dielectric layers are fabricated by thermal evaporation techniques in high vacuum of the order of 10 −6 Torr in a coplanar electrode structure. The channel length of the TFT is of 50 μm. The fabricated TFTs are annealed at 500 °C in air. The TFTs exhibit a field effect mobility 0.58 (cm 2 V −1 s −1 ). Use of a high dielectric constant (high‐ k ) gate insulator reduces the threshold voltage and subthreshold swing of the TFTs. The TFTs exhibit a low threshold voltage of 4 V. The calculated values of gain–bandwidth product and subthreshold swing are also evaluated and presented. The ON/OFF ratio of the TFT is found to be 10 6 .