Takuo Sugano

TL;DR: Deep-leve transient spectroscopy (DLTS) of bulk traps and interface states in Si MOS diodes is theoretically studied and energy levels, capture cross-sections and spatial and energy density distributions of majority-carrier traps are measured as discussed by the authors.

TL;DR: In this article, a method to calculate the energy level of trap states between amorphous SiO2 and the Si substrate with (111) orientation was proposed. But the method was not applied to the case of SiO 2 interfaces with or without microstructural defects.

TL;DR: In this article, electron spin resonance measurements of E' centers in SiO/sub 2/ films are consistent with the results of electrical measurements, suggesting that there is a tradeoff correlation between the density of electron traps and hole traps.

TL;DR: In this article, a semiconductor substrate is formed by irradiating a substrate with radioactive ray to generate lattice defects therein for making the entire substrate semi-insulating and rendering only the surface of the irradiated substrate semiconductive.

Abstract: The effects of minute amounts of impurities (H, OH, and F) in SiO/sub 2/ are investigated to obtain a guideline for improving the reliability of MOS devices. To examine the behavior of hydrogen, deuterium (D) is adopted as a tracer. The quantity of deuterium dissolved in SiO/sub 2/ is measured by the D(/sup 3/He,p)/sup 4/He nuclear resonant reaction (NRR) technique. The Influence of the impurities on the SiO/sub 2/-Si interface structure is studied by electron spin resonance (ESR) measurement. Hot-carrier injection with MOS capacitors and transistors are examined to determine the effects of minute impurities on the electrical characteristics of gate SiO/sub 2/ and the correlation of this effect with the NRR and ESR experimental results. It was found that significant amounts of D/sub 2/O are diffused into SiO/sub 2/, even at 200 degrees C, and these dissolved D/sub 2/O molecules are eliminated at temperatures above 700 degrees C. The number of unpaired bonds at the interface increases with decrease of dissolved water in SiO/sub 2/. The disappearance of the interface traps after high-temperature annealing above 800 degrees C is thought to be due to the viscous flow of SiO/sub 2/ and to the interface reoxidation. Reducing the hydrogen and relaxing the interface strain are essential for improving the MOS device endurance against hot carriers. >