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Al-rich thin films are synthesized by radio-frequency magnetron sputtering, followed by thermal annealing at 500°C for different durations to form Al/Al-rich diodes. The annealing causes reactions at the Al-rich interface, leading to an increase in Al concentration in the interface region. As a result, the current conduction of the diode is significantly enhanced, which results in anomalous capacitance-voltage (C-V) characteristics. The anomalous behaviors can be eliminated by reconstructing the C-V curve based on a four-element circuit model. The resistance of the Al-rich layer extracted from the C-V reconstruction shows power-law voltage dependence correlated with the current-conduction measurement.

In this brief, quenching of electroluminescence (EL) from Si-implanted silicon nitride (SNR) thin film under a forward bias has been observed. The quenching phenomenon is shown to be due to charge trapping in the defect states involved in the radiative recombination. The composite EL bands have different quenching rates, causing a change in the EL spectrum shape by the EL quenching. Release of the trapped charges by a low-temperature annealing at 120degC or an application of a reverse gate bias can partially recover the quenched EL both in the intensity and spectrum shape. The quenching phenomenon poses a serious challenge to the application of Si-implanted SNR thin films in light-emitting devices.

Strong visible electroluminescence (EL) has been observed from a 30 nm silicon nitride thin film multiply implanted with Si ions and annealed at 1100 degree celcius. The EL intensity shows a linear relationship with the current transport in the thin film at lower voltages, but a departure from the linear relationship with a quenching in the EL intensity is observed at higher voltages. The EL spectra show two primary EL bands including the predominant violet band at ∼ 3.0 eV (415 nm) and the strong green-yellow band at ∼ 2.2 eV (560 nm). Two weak bands including the ultraviolet band at ∼ 3.8 eV and the near infrared band at ∼ 1.45 eV emerge at high voltages. The evolution of each EL band with the voltage has been examined. The phenomena observed are explained, and the EL mechanisms are discussed. Published version

Anomalous capacitance-voltage (C-V) characteristics of Al/Al-rich Al2O3/p-Si capacitors have been observed. The measured C-V curves exhibit rolloffs and frequency dispersion in the accumulation region and voltage stresses cause both horizontal and vertical shifts of the C-V curves. These anomalous behaviors are mainly due to the large current conduction and the charge trapping in the Al-rich Al2O3 layer. The anomalous C-V characteristics have been reconstructed based on a four-element circuit model. With the reconstructed C-V curves, the capacitance of the Al-rich Al2O3 layer and the charging-induced flatband voltage shift can be determined.

Optical properties of implanted Si in a silicon nitride thin film have been determined with spectroscopic ellipsometry based on the Tauc–Lorentz (TL) model and the Bruggeman effective medium approximation. It is shown that the suppressed dielectric functions of the implanted Si are dominated by the energy transitions related to the critical point E2. The effect of thermal annealing on the dielectric functions of the implanted Si has been investigated. The analysis of the dielectric functions based on the evolution of the TL parameters can provide an insight into the structural changes in the implanted Si embedded in the Si3N4 matrix caused by the annealing. Published version