A Study on the Role of Pre-Cleaning and a New Method to Strengthen Gate Oxide Quality.

Isopropyl alcohol (IPA) has been conventionally used for pre-cleaning processes. As the device size decreased, the gate oxide layer became thinner. As a result, the quality of the gate oxide was degraded by a pre-cleaning process, and oxide reliabilities and product yield were affected.

Effect of Heat Budget After Capacitor Formation on the Leakage Current Characteristics of ZrO₂-Based High- Dielectrics for Next-Generation Dynamic Random-Access Memory Capacitors.

Successful development of 20 nm or smaller dynamic random-access memory (DRAM) requires reduction of the leakage current in capacitors with high- dielectrics. To reduce the leakage current of the capacitor, we fabricated a ZrO₂-based metal-insulator-metal (MIM) capacitor and investigated changes in leakage current characteristics associated with heat budget following capacitor formation. Leakage current characteristics were drastically degraded by applying an additional heat treatment to the MIM capacitor.

Direct evidence of flat band voltage shift for TiN/LaO or ZrO/SiO stack structure via work function depth profiling.

We demonstrated that a flat band voltage (V) shift could be controlled in TiN/(LaO or ZrO)/SiO stack structures. The V shift described in term of metal diffusion into the TiN film and silicate formation in the inserted (LaO or ZrO)/SiO interface layer. The metal doping and silicate formation confirmed by using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) line profiling, respectively.

Defect visualization of Cu(InGa)(SeS)2 thin films using DLTS measurement.

Defect depth profiles of Cu (In1-x,Gax)(Se1-ySy)2 (CIGSS) were measured as functions of pulse width and voltage via deep-level transient spectroscopy (DLTS). Four defects were observed, i.e.

Preparation and Characterization of P-Type and N-Type Doped Expanded Graphite Polymer Composites for Thermoelectric Applications.

In this work, we demonstrate that expanded graphite can be sufficiently dispersed in polymer solution to form suspensions. Thin composite films were prepared by casting and drying the suspensions. The thermoelectric properties of expanded graphite (ExG)-polymer composites were easily modified by chemical doping.

Abnormal Threshold Voltage Shifts in P-Channel Low-Temperature Polycrystalline Silicon Thin Film Transistors Under Negative Bias Temperature Stress.

In this research, we have investigated the instability of P-channel low-temperature polycrystalline silicon (poly-Si) thin-film transistors (LTPS TFTs) with double-layer SiO2/SiNx dielectrics. A negative gate bias temperature instability (NBTI) stress was applied and a turn-around behavior phenomenon was observed in the Threshold Voltage Shift (Vth). A positive threshold voltage shift occurs in the first stage, resulting from the negative charge trapping at the SiNx/SiO2 dielectric interface being dominant over the positive charge trapping at dielectric/Poly-Si interface.

Electrical Properties of Solution Processed In-Ga-ZnO Thin Film Transistors with Multi-Stacked Active Layer.

In this study, we prepared solution-based In-Ga-ZnO thin film transistors (IGZO TFTs) having a multistacked active layer. The solution was prepared using an In:Zn = 1:1 mole ratio with variation in Ga content, and the TFTs were fabricated by stacking layers from the prepared solutions. After we measured the mobility of each stacked layer, the saturation mobility showed values of 0.

Electrical Properties and Reliability Analysis of Solution-Processed Indium Tin Zinc Oxide Thin Film Transistors with O2-Plasma Treatment.

In this paper, we report the effects of O2-plasma treatment on the reliability and electrical properties of indium tin zinc oxide (ITZO) films. Excellent electrical properties, including a saturation mobility (μsat) of ~20.2 cm2/V · s, a threshold voltage (VTH) of ~-6.

Temperature-dependent electrical characteristics of c-Si and CIGS solar cells.

We characterized the electrical behavior of crystalline silicon (c-Si) and Cu(In(1-x)Ga(x))Se2 (CIGS) solar cells by current-voltage (I-V) and capacitance-voltage (C-V) methods. We investigated the temperature-dependent carrier transport mechanism by determining the parameters of ideality factor (n) and activation energy (E(a)) deduced from I-V measurements. CLGS solar cells, as a function of temperature, showed drastic changes in n and E(a) in the space charge region (SCR) that forms near the ZnS/CIGS interface.