Effect of SiO2 encapsulation on the nitrogen reorganization in GaNAs/GaAs single quantum well

Effects of SiO2, encapsulation and rapid thermal annealing (RTA) on the optical properties of GaNAs/GaAs single quantum well (SQW) were studied by low temperature photoluminescence (PL). A blueshift of the PL peak energy for both the SiO2-capped region and the bare region was observed. The results were attributed to the nitrogen reorganization in the GaNAs/GaAs SQW. It was also shown that the nitrogen reorganization was obviously enhanced by SiO2 cap-layer. A simple model [1] was used to describe the SiO2-enhanced blueshift of the low temperature PL peak energy.

Modulation magnesium-doping in AlGaN/GaN superlattices

Low resistivity of p-type Mg-doped AlGaN/GaN superlattices (SLs) is demonstrated. The resistivity of the SLs is less than 0.6 Omega .cm. and the measured hole concentration is higher than 1x10(18)cm(-3). The resistivity of SLs is much lower, and the hole concentration of SLs is much higher, than that of bulk GaN and AlGaN, The electrical properties of the SLs are less sensitive than the conventional bulk lavers.

Indium-doping enhanced two-dimensional-electron-gas performance in AlGaN/GaN heterostructures

Indium (In)-doping was applied in GaN layers during growth of AlGaN/GaN heterostructure with unintentionally doped or modulation Si-doped AlGaN layers. It was found that In-doping was effective in improving electron sheet density of two-dimensional-electron-gas (2DEG) in the heterostructures. Furthermore, In-doping also improved mobility in heterostructures with Si modulation-doped in AlGaN layers. The possible reasons were discussed. X-ray diffraction (XRD) and wet chemical etching revealed that crystalline quality of GaN was improved by In-doping. It was proposed that In-doping modified growth kinetics of GaN.

In situ annealing treatment and In-doping of GaN epilayers grown by MOVPE

The effects of in situ annealing treatment in the initial growth stage and In-doping during growth of the GaN on the material properties were investigated. GaN was grown by LP-MOVPE. In situ annealing reduced the full-width at half-maximum (FWHM) of X-ray rocking curves and reduced etch pit density of GaN films. It improved the optical properties of the epilayer. Undoped and In-doped GaN films of initial growth stage were investigated. It was found that morphology and optical properties were improved in In-doped samples. (C) 2000 Elsevier Science B.V. All rights reserved.

Influence of nitrogen implantation into the buried oxide on the radiation hardness of silicon-on-insulator wafers

摘要: In order to improve the total-dose radiation hardness of the buried oxide of separation by implanted oxygen silicon-on-insulator wafers, nitrogen ions were implanted into the buried oxide with a dose of 10(16)cm(-2), and subsequent annealing was performed at 1100 degrees C. The effect of annealing time on the radiation hardness of the nitrogen implanted wafers has been studied by the high frequency capacitance-voltage technique. The results suggest that the improvement of the radiation hardness of the wafers can be achieved through a shorter time annealing after nitrogen implantation. The nitrogen-implanted sample with the shortest annealing time 0.5 h shows the highest tolerance to total-dose radiation. In particular, for the 1.0 and 1.5 h annealing samples, both total dose responses were unusual. After 300-krad(Si) irradiation, both the shifts of capacitance-voltage curve reached a maximum, respectively, and then decreased with increasing total dose. In addition, the wafers were analysed by the Fourier transform infrared spectroscopy technique, and some useful results have been obtained.