Reduction of Three-Nucleon Potentials into Irreducible Tensors and Computation of Their Matrix Elements with Respect to the Triton Wave Function

Three-nucleon potentials due to 2π or 2(π+p) exchanges via Δ_, and those due to 2π exchange with all effects of S and P wave πN scatterings are reduced into sums of irreducible tensors in coordinate space. General expressions for the matrix elements of these three-nucleon potentials with respect to the triton wave function are presented

Acute eosinophilic pneumonia caused by cigarette smoking

金沢大学医薬保健研究域医学系It has been suggested that acute eosinophilic pneumonia (AEP) is associated with cigarette smoking because in Japan, the patients with AEP are young and have a high incidence of short-term smoking history. However, there has been no direct evidence to support that cigarette smoke causes AEP. Herein is reported the first case showing the direct evidence and a long-term clinical course of cigarette smoking-induced AEP, in which tolerance to repeated resumption of smoking cigarettes might have occurred. We should pay attention to the history of cigarette smoking in seeing patients with AEP, especially in young patients

Insulated gate and surface passivation structures for GaN-based power transistors

Recent years have witnessed GaN-based devices delivering their promise of unprecedented power and frequency levels and demonstrating their capability as an able replacement for Si-based devices. High-electron-mobility transistors (HEMTs), a key representative architecture of GaN-based devices, are well-suited for high-power and high frequency device applications, owing to highly desirable III-nitride physical properties. However, these devices are still hounded by issues not previously encountered in their more established Si- and GaAs-based devices counterparts. Metal–insulator–semiconductor (MIS) structures are usually employed with varying degrees of success in sidestepping the major problematic issues such as excessive leakage current and current instability. While different insulator materials have been applied to GaN-based transistors, the properties of insulator/III-N interfaces are still not fully understood. This is mainly due to the difficulty of characterizing insulator/AlGaN interfaces in a MIS HEMT because of the two resulting interfaces: insulator/AlGaN and AlGaN/GaN, making the potential modulation rather complicated. Although there have been many reports of low interface-trap densities in HEMT MIS capacitors, several papers have incorrectly evaluated their capacitance–voltage (C–V) characteristics. A HEMT MIS structure typically shows a 2-step C–V behavior. However, several groups reported C–V curves without the characteristic step at the forward bias regime, which is likely to the high-density states at the insulator/AlGaN interface impeding the potential control of the AlGaN surface by the gate bias. In this review paper, first we describe critical issues and problems including leakage current, current collapse and threshold voltage instability in AlGaN/GaN HEMTs. Then we present interface properties, focusing on interface states, of GaN MIS systems using oxides, nitrides and high-κ dielectrics. Next, the properties of a variety of AlGaN/GaN MIS structures as well as different characterization methods, including our own photo-assisted C–V technique, essential for understanding and developing successful surface passivation and interface control schemes, are given in the subsequent section. Finally we highlight the important progress in GaN MIS interfaces that have recently pushed the frontier of nitride-based device technology

Chemical and Potential Bending Characteristics of SiNx/AlGaN Interfaces Prepared by In Situ Metal-Organic Chemical Vapor Deposition

We investigate the chemical and potential-bending characteristics of in situ SiNx/AlGaN interfaces prepared by metal-organic chemical vapor deposition. X-ray photoelectron spectroscopy showed that the in situ SiNx layer had typical chemical binding energies corresponding to the Si-N bonds. The in situ SiNx deposition brought no chemical degradation on the AlGaN surface at the SiNx/AlGaN interface, whereas the ex situ deposition of SiNx by a plasma process induced chemical disorder on the AlGaN surface including a composition change and the formation of interfacial oxides. A significant reduction in the surface band bending was observed on the AlGaN surface after the in situ SiNx passivation, probably due to a decrease in the surface state density