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The formation of Si quantum dots on SiO[sub 2] by chemical vapor deposition of SiH[sub 4] has been investigated in the range from the submonolayer to the complete coverage with Si. In order to investigate the very early stages of the nucleation process of Si on SiO[sub 2], the energy filtered transmission electron microscopy has been chosen as the main characterization technique, because of the high spatial resolution typical of the transmission electron microscopy analysis, coupled to the compositional information obtained by the electron energy loss spectroscopy. The plan view configuration has been used to measure the dot size distributions down to dimensions of about 1 nm, and in cross section to evaluate the dot wetting angle. For all the several experimental conditions, a wetting angle distribution has been obtained and has shown to be centered at about 90°. Data on the dot size distributions are shown and discussed in the framework of a continuous nucleation model, which has been implemented to take into account the dot coalescence process contribution. Through the comparison with experimental data the relevant thermodynamic parameters of the process have been evaluated: the critical radius, the free energy barrier for nucleation, and the concentration of nucleation sites. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Metal-oxide-semiconductor capacitors in which the gate oxide has been replaced with a silicon rich oxide (SRO) film sandwiched between two thin SiO[sub 2] layers are presented and investigated by transmission electron microscopy and electrical measurements. The grain size distribution and the amount of crystallized silicon remaining in SRO after annealing have been studied by transmission electron microscopy, whereas the charge trapping and the charge transport through the dots in the SRO layer have been extensively investigated by electrical measurements. Furthermore, a model, which explains the electrical behavior of such SRO capacitors, is presented and discussed. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated the structural properties of superconducting niobium/palladium multilayers using secondary ion mass spectroscopy and x-ray reflectivity. Experimental details; Results and discussion; Conclusions.

Focuses on a study on the effects of nitric oxide postannealing on the leakage current of thin gate oxides. Application of nitridation treatment of thin oxides; Effect of nitrogen incorporation on quasistatic characteristics of the oxides; Explanation of the asymmetric behavior shown by the leakage current with the injection polarity.

Discusses a study that examined gallium arsenide:carbon (C) and Al[subx]Ga[sub1-x]As:C films, which were grown by solid-source molecular-beam epitaxy. Indication of a comparison between x-ray diffraction and Hall-effect data; Concentration of carbon incorporated on arsenic sites; Growth techniques that demonstrated the advantages in the use of carbon.

Presents information on a study which analyzed silicon/germanium multilayers grown by molecular beam epitaxy. Experimental procedure; Results; Discussion.

Presents a study which characterized the structure of zinc sulphide semiconductor compound grown by hydrogen transport vapor-phase epitaxy on (100)-oriented GaAs substrates. Band-gap value of the semiconductor compound; Experimental details; Results and discussion; Conclusions.

We study the role that the denuded zone around Si nanocrystals obtained by chemical vapor deposition plays on the fluctuations of the dot surface coverage. In fact, the capture mechanism of the silicon adatoms in the proximity of existing dots restricts the number of possible nucleation sites, the final dot size, and the dot position, thus driving the process toward partial self-order. We numerically evaluate the relative dispersion of surface coverage for several gate areas and compare the results to the fully random case. The coverage dispersion is related to the fluctuations from bit to bit of the threshold voltage window (ΔVth) distribution of nanocrystal memories. The evaluations, compared to experimental data on ΔVth extrapolated to small gate areas, provide very favorable projections on the scalability of these memories. [ABSTRACT FROM AUTHOR]

Provides information on an experiment using the sol-gel process to prepare osmium doped tin oxide thin films. Methodology used to conduct the experiment; Results of the experiment; Conclusion reached.

We report on the improvement of short circuit current (JSC), fill factor (FF), and open circuit resistance (ROC) in hydrogenated amorphous silicon (a-Si:H) photovoltaic cells with a p-type/intrinsic/n-type structure, achieved by the addition of an ultra-thin molybdenum film between the p-type film and the transparent conductive oxide/glass substrate. For suitable conditions, improvements of ≈10% in average internal quantum efficiency and up to 5%-10% under standard illumination in JSC, FF, and ROC are observed. These are attributed to the excitation of surface plasmon polariton modes of the a-Si:H/Mo interface. [ABSTRACT FROM AUTHOR]

We investigated the feasibility of electron programing and hole erasing in silicon nanocrystal Flash memory cells with fin field-effect transistor architecture having ultrashort channels (90 nm). Experiments show that, by choosing a proper program/erase condition, very large threshold voltage windows can be achieved, compatible with the needs of multilevel cells. These performances are coupled to excellent retention at high temperature. The obtained results evidence that hole trapping is less affected by electric field and temperature stress compared to electron trapping. Qualitative explanations for this behavior are given. [ABSTRACT FROM AUTHOR]

In this work, we present an experimental study on the single-electron effects observed at room temperature in silicon nanocrystal memories. The electrical characterization has been performed by means of a purposely designed low noise high bandwidth measurement system. Relevant statistical properties of the threshold voltage shifts induced by single-electron trapping and detrapping in the silicon dots are reported. The kinetics of electron capture and emission is also discussed. [ABSTRACT FROM AUTHOR]

The induced changes of the flatband voltage by the location of holes in a silicon-rich oxide (SRO) film sandwiched between two thin SiO[sub 2] layers [used as gate dielectric in a metal–oxide–semiconductor (MOS) capacitor] can be used as the two states of a memory cell. The principle of operation is based on holes permanently trapped in the SRO layer and reversibly moved up and down, close to the metal and the semiconductor, in order to obtain the two logic states of the memory. The concept has been verified by suitable experiments on MOS structures. The device exhibits an excellent endurance behavior and, due to the low mobility of the holes at low field in the SRO layer, a much longer refresh time compared to conventional dynamic random access memory cells. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the intrinsic dielectric breakdown of gate oxide layers in polycrystalline Si-SiO[sub 2]-Si metal/oxide/semiconductor (MOS) capacitors after stress with constant current either under Fowler-Nordheim or under hot electron injection. Occurrences of soft breakdowns without thermal damage in the MOS structure; Types of stress that determines the breakdown mode.

We have compared the thermal damage in ultrathin gate SiO[sub 2] layers of 5.6 and 3 nm thickness after intrinsic dielectric breakdown due to constant voltage Fowler–Nordheim stress. The power dissipated through the metal–oxide–semiconductor capacitor during the breakdown transient, measured with high time resolution, strongly decreases with oxide thickness. This is reflected in a noticeable reduction of the thermal damage found in the structure after breakdown. The effect can be explained as the consequence of the lower amount of defects present in the oxide at the breakdown instant and of the occurrence of a softer breakdown in the initial spot. The present data allow us to estimate the power threshold at the boundary between soft and hard breakdown, and they are compared to numerical simulations of heat flow. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]