Volume 87, Issue 7, 01 April 2000
Index of content:
- DEVICE PHYSICS (PACS 85)
Analysis of postirradiation annealing of n-channel power vertical double-diffused metal–oxide–semiconductor transistors87(2000); http://dx.doi.org/10.1063/1.372368View Description Hide Description
The behavior of densities of the oxide trapped charge and the interface traps in gamma-ray irradiated n-channel power vertical double-diffused metal–oxide–semiconductor transistors during annealing at different temperatures and gate biases has been investigated. The experimental results have revealed the existence of a latent interface trap buildup (LITB) process. By use of numerical modeling, based on the hydrogen–water (H–W) model, the LITB process has been successfully simulated. The interface trap densities have been determined by both the midgap and the charge pumping methods, and the results have shown good qualitative agreement between these two methods. Isochronal annealing and switching bias experiments have also been performed. The experimental results are consistent with the H–W model.
87(2000); http://dx.doi.org/10.1063/1.372369View Description Hide Description
Si implantations into undoped have been carried out to obtain n-layers suitable for device applications. Different doses and energies have been analyzed. After rapid thermal annealing at for 10–20 s, electrical activations of about 100%, and mobilities as high as were obtained. Different Hall measurements show that there is no redistribution of the dopants.Photoluminescence measurements demonstrate the satisfactory recrystallization of the lattice and the excellent activation of the dopants. Electrical characteristics of junctions made by Si implantation into Zn-doped are described. Junction behavior at forward bias could be explained by recombination in the space-charge zone mechanisms, whereas different tunneling processes dominate at reverse bias.
Analysis of electric field distribution in GaAs metal–semiconductor field effect transistor with a field-modulating plate87(2000); http://dx.doi.org/10.1063/1.372370View Description Hide Description
Electric field distribution in the channel of a field effect transistor(FET) with a field-modulating plate (FP) has been theoretically investigated using a two-dimensional ensemble Monte Carlo simulation. This analysis revealed that the introduction of FP is effective in canceling the influence of surface traps under forward bias conditions and in reducing the electric field intensity at the drain side of the gate edge under pinch-off bias conditions. This study also found that a partial overlap of the high-field region under the gate and that at the FP electrode is important for reducing the electric field intensity. The optimized metal–semiconductor FET with FP (FPFET) exhibited a much lower peak electric field intensity than a conventional metal–semiconductor FET. Based on these numerically calculated results, we have proposed a design procedure to optimize the power FPFET structure with extremely high breakdown voltages while maintaining reasonable gain performance.
Influence of substrate dopant concentration on electrical properties and residual defects in junction formed by low-temperature post-implantation annealing87(2000); http://dx.doi.org/10.1063/1.372371View Description Hide Description
Dependence of the leakage currents in implanted junctions on the dopant concentration of the n-type substrate was investigated. It was clarified that the leakage currents of low-temperature-annealed junctions increase as the substrate dopant concentration increases, while high-temperature-annealed junctions have the opposite dependence. We demonstrate that low-leakage currents can be achieved in low-temperature-annealed junctions by using lightly dopedsilicon substrate. It was confirmed that the higher leakage currents in low-temperature-annealed junctions originate from the implantation-induced defects existing deeply in the substrate. Considering the results of both implanted junction and implanted junction, we discuss an implantation-induced defect generation mechanism.
Surface recombination measurements on III–V candidate materials for nanostructure light-emitting diodes87(2000); http://dx.doi.org/10.1063/1.372372View Description Hide Description
Surface recombination is an important characteristic of an optoelectronic material. Although surface recombination is a limiting factor for very small devices it has not been studied intensively. We have investigated surface recombination velocity on the exposed surfaces of the AlGaN,InGaAs, and InGaAlP material systems by using absolute photoluminescence quantum efficiency measurements. Two of these three material systems have low enough surface recombination velocity to be usable in nanoscale photonic crystal light-emitting diodes.