High-performance InGaZnO thin-film transistor incorporating a HfO₂/Er₂O₃/HfO₂stacked gate dielectric

Abstract

ARTICLE This journal isIn this paper, a HfO 2 /Er 2 O 3 /HfO 2 (HEH) stacked structure was developed as a gate dielectric for amorphous InGaZnO (α-IGZO) thin-film transistor (TFT) applications. Atomic force microscopy and X-ray photoelectron spectroscopy were used to study the morphological and chemical features of Er 2 O 3 and HEH films. In comparison to the Er 2 O 3 dielectric, the α-IGZO TFT device incorporating a HEH stacked dielectric exhibited a lower threshold voltage of 0.7 V, a higher I on /I off current ratio of 2.86×10 7 , a larger field-effect mobility of 15.8 cm 2 /V-s, and a smaller subthreshold swing of 101 mV/decade, suggesting a smooth surface at the dielectricchannel interface. Furthermore, the threshold voltage stability of α-IGZO TFT under positive gate voltage stress can be improved by using a HEH stacked structure. structure is a promising gate dielectric material to fabricate α-IGZO TFTs for future display applications.

Exploring the optical properties of La2Hf2O7:Pr3+ nanoparticles under UV and X-ray excitation for potential lighting and scintillating applications

“…41,42 Upon doping the Pr 3+ ions, it can be seen that both peaks shift to higher BE values, which can be attributed to different chemical environment around the La 3+ ions. On the other hand, most reports [43][44][45] depict a clear splitting of the Hf 4f peak to 4f 7/2 and 4f 5/2 similar to our observation. Fitting the curves of the Hf 4f core levels (Fig.…”

Glucose Sensing Using Functionalized Amorphous In–Ga–Zn–O Field-Effect Transistors

“…Our device processing was optimized for IGZO TFT operation in air where the turn-on voltage ( V ON ) was ∼0 V. There are several approaches that can be undertaken to reduce V ON for the IGZO TFTs in aqueous media so that low-voltage operation can be obtained. For example, to reduce the operating voltage, a thin high- k dielectric (e.g., Al 2 O 3 , HfO 2 , and so on) can be used as opposed to the relatively thick SiO 2 used in these studies. Other methods include varying IGZO thickness, deposition (oxygen free deposition) and annealing conditions (temperature and ambient conditions) can increase the number of free carriers in the channel and result in a negative V ON shift. , Finally, fabrication of fully transparent, flexible sensors will open up new opportunities for ubiquitous sensing for human health.…”

Stacked Top Gate Dielectrics in Dual Gate Ion Sensitive Field Effect Transistors: Role of Interfaces

“…There are several reports of utilization of single dielectric materials such as SiO 2 , Ta 2 O 5 , − Y 2 O 3 , and HfO 2 as the TG dielectric in a-IGZO TFT based ISFETs. , Stacks of dielectrics could be utilized to obtain device properties better than when only a single material is used by taking advantages of the beneficial properties of the constituent materials. Stacked dielectrics such as Ta 2 O 5 /Al 2 O 3 , HfO 2 /ErO 2 /HfO 2 , Al 2 O 3 /HfO 2 /Al 2 O 3 , and SiO 2 /Al 2 O 3 /HfO 2 have been reported to improve TFT and metal insulator metal (MIM) characteristics. However, there are very limited studies on the use of stacked TG dielectrics in DGISFETs, one report being with SiO 2 /Ta 2 O 5 .…”