Characteristics Of MIS Capacitors Research Articles

Discriminating High k Dielectric Gas Sensors

High temperature gas sensors for the detection of harmful gases under extreme conditions have been demonstrated. Here, we show the detection and selective response of two SiC based MIS sensor structures with HfO2 and TiO2 high κ dielectric layers to two different hydrogen containing gases. The structures utilise a Pt catalytic gate contact and a high-κ dielectric that was grown on a thin SiO2 layer, which was thermally grown on the Si face of epitaxial 4H SiC. The chemical characteristics of MIS capacitors have been studied in N2, O2, H2 and CH4 ambients at 573K. The data show a positive flatband voltage shift for oxygen and methane with respect to the nitrogen baseline, whilst hydrogen shows a negative shift. The response for the TiO2 based sensor is significantly larger than that of the HfO2 based device for hydrogen, enabling discrimination of gases within a mixture.

Formation of Metal Silicide Nanodots on Ultrathin SiO<sub>2</sub> for Floating Gate Application

We demonstrated a new fabrication method of Pt- and Ni-silicide nanodots with an areal density of the order of ~1011 cm-2 on SiO2 through the process steps of ultrathin metal film deposition on pre-grown Si-QDs and subsequent remote H2 plasma treatments at room temperature. Verification of electrical separation among silicide nanodots was made by measuring surface potential changes due to electron injection and extraction using an AFM/Kelvin probe technique. Photoemission measurements confirm a deeper potential well of silicide nanodots than Si-QDs and a resultant superior charge retention was also verified by surface potential measurements after charging to and discharging. Also, the advantage in many electron storage per silicide nanodot was demonstrated in C-V characteristics of MIS capacitors with silicide nanodots FGs.

Impact of Dielectric Material Selection on Electrical Characteristics of High-k/Ge Devices

The impact of high-k material selection on the electrical characteristics of high-k/Ge MIS capacitors is investigated. The Y2O3/Ge can maintain good electrical characteristics even after annealing at 600{degree sign}C, while HfO2/Ge seriously degrades. The Ge diffusion into Y2O3 occurs during the annealing, but the characteristics of MIS capacitors do not change even by an intentional doping of Ge into high-k films. The Ge substrate quality is not significantly affected by metal diffusion, neither. These results clearly show that the critical difference between HfO2/Ge and Y2O3/Ge systems is, the ability to form a high quality interface through interface reaction.

Characteristics of MIS capacitors using Ta 2O 5 films deposited on ZnO/p-Si

The electronic availability of ZnO thin film as a semiconducting material for MIS structure was investigated by depositing a dielectric Ta 2O 5 thin layer. A ZnO (100 nm) thin film was deposited on p-Si by rf magnetron sputtering. High frequency (1 MHz) capacitance–voltage ( C– V) and conductance–voltage ( G– V) characteristics of the deposited Ta 2O 5 films were measured. The values of flat-band ( V fb) voltages are found to be −1.6 V and the negative flat-band voltage shift with respect to the ideal MIS capacitor indicates the existence of positive charge trapping in the plasma grown Ta 2O 5 films. The fixed oxide charge density ( Q f/ q) is found to be 2.48×10 11 cm −2 while the interface trap charge density ( D it) at mid-gap, calculated using Hill’s method from the G– V curve, is found to be 1.22×10 12 cm −2 eV −1.

Determination of capture rates from non-equilibrium quasistaticCU characteristics of MIS capacitors

The analysis of non-equilibrium quasistatic CU curves of MIS capacitors reveales that it is possible to distinguish several groups of states differing by their respective effective capture cross sections. A relation between the demarcation energy that separates states in quasi-equilibrium from those in non-equilibrium at the oxide-semiconductor interface, and the equivalent frequency of the quasistatic CU method, is derived. Using the Berglund integral, the surface potential can be calculated even under non-equilibrium conditions. States in the upper half of the gap are found to have up to three orders higher capture cross section for holes compared to that of states in the lower half of the gap.

Simple formulas for analysis of C-V characteristics of MIS capacitor

Paper presents few simple formulas which permit for a quick determination of the parameters of MIS capacitor on the grounds of the high-frequency C-V characteristics of MOS capacitor. These formulas allow for a simple and quick interpretation of the experimental data and can be used in the design of VLSI circuits as well as to the automatization of measurement on a technological line. The error of the proposed formulas was analyzed in the range U F = 9–16.

Graphic method of substrate doping determination from C– V characteristics of MIS capacitors

A simple graphical method is presented which determines of the Fermi potential (substrate doping) from the high-frequency C– V characteristic of the MIS capacitor. This method is of general application and can be used for the study of any dielectric-semiconductor system at various ambient temperatures.

Effect of temperature and voltage sweep rate on[formula omitted]characteristics of MIS capacitors: L. S. Wei and J. G. Simmons. Solid State Electron.17, 1021 (1974)

Effect of temperature and voltage sweep rate on[formula omitted]characteristics of MIS capacitors: L. S. Wei and J. G. Simmons. Solid State Electron.17, 1021 (1974)

CV and IV characteristics of MIS structures with pyrolytic SiO 2 as dielectric

The CV and IV characteristics of MIS capacitors with pyrolytically deposited SiO 2 as dielectric have been studied. Two features were found to be typical: a non-equilibrium lowering of the capacitance in the inversion mode, and a break in the original IV characteristics. These effects appear after a given value of the negative voltage has been applied on the metal electrode. A qualitative treatment attributes the observed effects to the considerable conductance of the dielectric.