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A novel tetraethylorthosilicate (TEOS)/oxynitride stack gate dielectric for low-temperature poly-Si thin film transistors, composed of a plasma-enhanced chemical vapor disposition (PECVD) thick TEOS oxide/ultrathin oxynitride grown by PECVD N2O plasma, is proposed. The proposed novel stack oxide has better interface quality, lower bulk-trap density, and higher long-term reliability than PECVD TEOS dielectrics.

A statistical model for extracting geometrical variations in nominally identical devices fabricated in close proximity to each other is provided. Related geometrical variations, namely corner influences, where the source and drain encounter the isolation edges are examined and incorporated in the model.

A simple method to determine the interface and bulk density of states in polycrystalline silicon thin-film transistors is presented. Both interface and bulk traps were found to consist of deep states with constant density near the mid-gaps and band-tails with energy increasing exponentially with the energy.

A magnetic tunnel transistor (MTT) with a full epitaxial [Co.sub.66][Fe.sub4]/Au/[Co.sub.66][Fe.sub.34] spin valve base, grown on GaAs, is presented. The layer structure of the system is analyzed by TEM, XPS, and STM. For a bias voltage of 1.1 V, the MTT shows a magneto current ratio of 85% and a transfer ratio of 1.5 * [10.sup.-6.] We ascribe these low values to the, although epitaxial, rough structure of the sample. Index Terms--Epitaxial, magnetic tunnel transistor, spin valve.

Very good quantitative agreement was found between the experimental and simulated switching transients of a Si avalanche transistor at extreme currents. Marked current localization was found, which was of a non destructive character with nanosecond current pulses due to a very significant reduction in the residual voltage across the transistor at high current densities and specific location of the region of intensive heat generation.

The resonant plasma waves oscillations in several gate-length InGaAs high electron mobility transistors (HEMTs) are measured. A numerical approach is developed that is based on hydrodynamic equations coupled to a pseudo-two-dimensional Poisson solver and a comprehensive spectroscopy of plasma waves in HEMTs is described.

Carrier mobilities in ambipolar field-effect transistors (FETs) are analyzed by using a rubrene single crystal assembled with Au/Ca electrodes and Si[O.sub.2] gate insulators modified by polymethylmethacrylate (PMMA), parylene-C, and hexamethyldisilazane (HMDS). The shift of light emitting with applied gate voltage is seen in a device with PMMA modified insulator and Au-Ca asymmetric metals.

The analysis of the data following the McWhorter model for the low frequency noise in amorphous Si thin film transistors (TFTs) with Si[N.sub.x] gate dielectric has shown relatively low density of traps. The value is close to the lower limit for amorphous and polycrystalline Si TFTs and the trap density has increased with the increase of the gate voltage.