Title :
Improved Performance of InGaZnO Thin-Film Transistor With HfLaO Gate Dielectric Annealed in Oxygen
Author :
Qian, L.X. ; Lai, P.T.
Author_Institution :
Electr. & Electron. Eng. Dept., Univ. of Hong Kong, Hong Kong, China
Abstract :
We have fabricated an amorphous InGaZnO thin-film transistor with HfLaO gate dielectric, and the influence of annealing the gate dielectric in oxygen on the device characteristics is investigated in detail. It is demonstrated that this annealing treatment can effectively suppress the negative oxide charges. In addition, the effect of this annealing treatment to suppress the acceptor-like border and interface traps has been discovered, which can explain the unusual phenomenon of counterclockwise hysteresis. Accordingly, a record-high saturation carrier mobility of 35.2 cm2/V ·s has been achieved for the device, and its threshold voltage, subthreshold swing, and on-off current ratio are 2.8 V, 0.292 V/dec, and 5.2 ×106, respectively.
Keywords :
amorphous state; carrier mobility; dielectric hysteresis; dielectric materials; gallium compounds; indium compounds; magnetic hysteresis; simulated annealing; thin film transistors; zinc compounds; HfLaO; InGaZnO; acceptor-like border; amorphous thin-film transistor; annealing treatment; carrier mobility; counterclockwise hysteresis; gate dielectric annealing; interface traps; negative oxide charges; oxygen; voltage 2.8 V; Annealing; Dielectrics; Electron traps; Hafnium compounds; Hysteresis; Logic gates; Thin film transistors; Amorphous InGaZnO (a-IGZO); HfLaO; annealing; high-k; mobility; thin-film transistor (TFT);
Journal_Title :
Device and Materials Reliability, IEEE Transactions on
DOI :
10.1109/TDMR.2013.2275191
