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This paper investigates the ability of second harmonic generation (SHG) to probe the passivation quality of atomic layer deposited Al2O3 on Si by estimating the induced interface electric field due to fixed charges in the oxide. Samples with various oxide charges (Qox) and interface state densities (Dit) were fabricated, using different deposition parameters. The samples were characterized by capacitance-voltage (C-V) and microwave photoconductance decay measurements in order to evaluate Qox and Dit, as well as the effective minority carrier lifetime τeff. The SHG results were consistent with Qox, Dit, and τeff values, proving the ability of the technique to monitor the interfacial quality in a contactless and non-destructive way. Optical simulations which use the electric field values obtained from the C-V measurements could reproduce the measured SHG signal. This demonstrates that SHG coupled with optical simulation can give access to the electric field magnitude and thus characterize the electrical properties of oxide/Si interfaces. [ABSTRACT FROM AUTHOR]

The influence of top free-surface states on the pseudo metal oxide semiconductor field effect transistor (pseudo-MOSFET) characteristics are investigated by comparing passivated versus nonpassivated samples. The results show that in state of the art ultrathin silicon on insulator structures, the preparation and properties of the free surface are no longer negligible.

This paper investigates the total ionizing dose response of advanced nonplanar triple-gate transistors with short gate length, as a function of device geometry. Experiments and three-dimensional (3-D) simulations using a radiation dedicated code are used to analyze the buildup of a trapped charge in the buried oxide and its impact on the device electrical characteristics. The behaviors of three prospective nonplanar devices are detailed and compared to the total ionizing dose degradation of a planar fully depleted single-gate architecture. The [OMEGA]-gate FET is shown to be the most tolerant to a 500 krad(Si[O.sub.2]) total dose exposure thanks to the efficient control provided by the lateral gates over the electrostatic potential throughout the Si film and essentially at the Si fin/BOX interface. Index Terms--Fully depleted, multiple-gate transistors, nonplanar architectures, silicon-on-insulator (SOI), total ionizing dose tolerance.

Low-frequency noise characteristics of the silicon-on-insulator four-gate transistor [G(super 4)-field-effect transistor]are reported and the noise power spectral density as a function of biasing conditions is presented and compared for surface and volume conduction modes. It is shown that, for the same drain current, the volume of the transistor generates less noise that its surface.

Total ionizing dose effects are investigated for the first time in deca-nanometer fully depleted (FD) silicon-on-insulator (SOI) devices. Charge trapping and the influence of device architecture are investigated in transistors with and without external body contacts. A radiation-induced high current regime is measured in floating body devices, both at high and low drain voltages. The mechanism responsible for the onset of this high current regime is investigated by 2D numerical simulations, and shown to result from the combined effect of short gate length and floating body potential in the intrinsic Si film. Transistors with a doped Si film are less sensitive to the high current regime. The use of external body contact in the device architecture completely stops the onset of high current regime, whatever the device gate length. Index Terms--Fully depleted, NMOS transistors, silicon on insulator, total dose irradiation.

The current-voltage, transconductance and threshold voltage characteristics of the four-gate SOI transistor have systematically been presented and analyzed. The main parameters threshold voltage, swing, mobility are extracted and shown to be optimized for particular combinations of gate biasing.

Pseudo-metal-oxide-semiconductor (MOS) silicon-on-insulator (SOI) transistors are used to study the total ionizing dose response of buried oxides. The concentrations of radiation-induced oxide-trap and interface-trap charge are separated using midgap and dual-transistor charge separation analysis techniques. Dual-transistor analysis is shown to be especially well suited for charge separation of pseudo-MOSFETs ([PSI]-MOSFETs) because the electron conduction mode of this simple point-contact device resembles an nMOS transistor, and the hole conduction mode resembles a pMOS transistor. That this is a single device ensures that the dual-transistor assumption of equal oxide-trap charge in otherwise identical n and pMOS transistors is satisfied automatically. Both electron and hole conduction current-voltage (I-V) traces must extrapolate to a common, physically realistic midgap voltage; this is employed as a test for the self-consistency of [PSI]-MOSFET data. Charge separation performed using midgap and dual-transistor analyses show good agreement for the devices employed in this paper. Index Terms--Charge separation, dual transistor method, midgap method, pseudo-MOSFET, SOI transistor.