Fundamentals Of Modern Vlsi Devices

Effective Encapsulation of ZnO Thin Film Transistors Controlled by Thermal Energy

In this study, we showcase the use of silicon dioxide (SiO2) nanoparticles and hexamethyldisilazane (HMDS) treatment to regulate the thin film morphology and manipulate charge transport of solution-processed, small-molecular, organic semiconductors. 6,13-Bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) was blended with SiO2 nanoparticles as an exemplary organic semiconductor. A higher concentration of SiO2 nanoparticles were observed near the edge of TIPS pentacene crystals and enlarged the width of crystal edges. This greatly reduced the dendritic crystal growth pattern of TIPS pentacene and contributed to its enhanced orientation uniformity. In addition, the HMDS treatment effectively passivated the silanol groups on the hydrophilic gate dielectrics. As a result, bottom-gate, top-contact TIPS pentacene/SiO2 nanoparticle-based organic thin-film transistors boosted a performance consistency enhancement (defined by the ratio of average mobility to the standard deviation of mobility). The combinational approach to employ SiO2 nanoparticles and HMDS treatment as demonstrated in this work sheds light on important applications in high-performance organic electronics devices on flexible substrate.

Tuning charge transport in organic semiconductors with nanoparticles and hexamethyldisilazane

Bias-stress stability of top-gate coplanar a-ITGZO TFTs with HfO2 and HfAlO gate dielectrics

Analytical drain current and capacitance model is developed for the amorphous InGaZnO (a-IGZO) thin-film transistor (TFT). The numerical Pao–Sah model is presented to describe the temperature characteristics considering the deep and tail trap states in the energy gap of the a-IGZO thin film. The numerical model is successful for the TFT in both the subthreshold regime and the above-threshold regime. In the subthreshold regime, considering that the trapped electron concentration in the deep trap states dominates the Poisson’s equation, the surface-potential-based analytical model is presented. In the above-threshold regime, the threshold-voltage-based analytical model is presented. Applying the smooth function to connect the subthreshold model and the above-threshold model, the analytical compact model is obtained. The compact model is verified by the numerical Pao–Sah model and the available experimental data from 253 to 393 K. Furthermore, the temperature characteristics of the field-effect mobility are discussed.

Analytical Drain Current and Capacitance Model for Amorphous InGaZnO TFTs Considering Temperature Characteristics

A full capacitance model for Amorphous Oxide Semiconductor Thin Film Transistors (AOSTFTs), considering the effect of the drain contact overlap in bottom gate passivated structures is presented. It is shown that this drain overlap, on top of the passivation layer, serves as a second gate with an applied voltage equal to VDS. When VDS > VT the semiconductor-passivation (S-P) interface will be in accumulation and the behavior of the different capacitance is affected. An expression to represent this effect is included in the present model. The overlap capacitance between gate and drain/source, as well as the effect of reducing the channel capacitance as the drain is increased, are also considered by the model. The calculated capacitance is a function of the threshold voltage, (VT), the mobility and saturation parameters (γa ,αs), and the sharpness of the knee region m, which are extracted using the Unified Model and Extraction Method (UMEM) for AOSTFTs. Results are compared with simulated and experimental data.

Full capacitance model, considering the specifics of amorphous oxide semiconductor thin film transistors structures

High performance, low temperature processed Hf-In-Zn-O/HfO2 thin film transistors, using PMMA as etch-stop and passivation layer

http://ojs.fei.edu.br/ojs/index.php/JICS/article/download/446/288

Bias Stress Effects in Low Temperature Amorphous Hf-In-ZnO TFTs Using RF-sputtering HfO2 as High-k Gate Dielectric

The electrical properties of RF magnetron sputtered HfO 2 layers as dielectric and Hafnium-Indium-Zinc-Oxide HIZO as semiconductor in metal-insulator-semiconductor (MIS) structures are investigated. The dielectric constant of the HfO 2 layer was around 9 measured at 10 kHz. The critical electric field was higher than 5×105 V/cm and the leakage current below 5×10−9 A/cm2. The effective charged density of interface states in the order of 5×1012 cm−2. Flat band shift due to polarization of the dielectric at voltage rage between −5 and 5 V is below 0.5 V. The RF deposited HIZO layer presents higher density of interface and bulk traps than similar layers deposited by other more complex techniques requiring higher processing temperature. However, results indicate that they can still be used in low voltage range amorphous oxide semiconductor thin film transistors AOSTFTs.

Characterization of HfO 2 on Hafnium-Indium-Zinc Oxide HIZO layer metal-insulator-semiconductor structures deposited by RF sputtering

Bias stress study is presented in Metal-Insulator-Semiconductor structure using Indium-Gallium-Zinc oxide film on top of HfO2, deposited by pulsed laser deposition and atomic layer deposition, respectively. The produced effect on this interface is analyzed through hysteresis measurements at different bias conditions for several periods of time.

http://ieeexplore.ieee.org/iel7/7389728/7395064/07395135.pdf

I. Hernandez

Papers

Full capacitance model, considering the specifics of amorphous oxide semiconductor thin film transistors structures

High performance, low temperature processed Hf-In-Zn-O/HfO2 thin film transistors, using PMMA as etch-stop and passivation layer

Bias Stress Effects in Low Temperature Amorphous Hf-In-ZnO TFTs Using RF-sputtering HfO2 as High-k Gate Dielectric

Characterization of HfO 2 on Hafnium-Indium-Zinc Oxide HIZO layer metal-insulator-semiconductor structures deposited by RF sputtering

Bias stress study of Metal-Insulator-Semiconductor structures with pulsed laser deposited InGaZnO on atomic layer deposited HfO2