Surface Properties of AZ31B Magnesium Alloy by Oxygen Plasma Immersion Ion Implantation

Oxygen plasma immersion ion implantation （PIII） has been conducted on AZ31B magnesium alloy using different bias voltages. The modified layer is mainly composed of MgO and some MgAl2O4. Results form Rutherford backscattering spectrometry （RBS） and X-ray photoelectron spectroscopy （XPS） indicate that the bias voltage has a significant impact on the structure of the films. The oxygen implant fluences and the thickness of the implanted layer increase with higher bias voltages. A high bias voltage such as 60 kV leads to an unexpected increments in the oxygen-rich layer＇s thickness compared to those of the samples implanted at 20 kV and 40 kV. The hardness is hardly enhanced by oxygen PIII. The corrosion resistance of magnesium alloy may be improved by a proper implantation voltage.

Improvement on the breakdown voltage for silicon-on-insulator devices based on epitaxy-separation by implantation oxygen by a partial buried n^+-layer

A novel silicon-on-insulator （SOI） high-voltage device based on epitaxy-separation by implantation oxygen （SIMOX） with a partial buried n＋-layer silicon-on-insulator （PBN SOI） is proposed in this paper. Based on the proposed expressions of the vertical interface electric field, the high concentration interface charges which are accumu- lated on the interface between top silicon layer and buried oxide layer （BOX） effectively enhance the electric field of the BOX （EI）, resulting in a high breakdown voltage （BV） for the device. For the same thicknesses of top silicon layer （10 μm） and BOX （0.375 μm）, the EI and BV of PBN SOI are improved by 186.5% and 45.4% in comparison with those of the conventional SOI, respectively.

Surface defects,stress evolution,and laser damage enhancement mechanism of fused silica under oxygen-enriched condition

Oxygen ions(O;)were implanted into fused silica at a fixed fluence of 1×10^(17) ions/cm^(2) with different ion energies ranging from 10 ke V to 60 ke V.The surface roughness,optical properties,mechanical properties and laser damage performance of fused silica were investigated to understand the effect of oxygen ion implantation on laser damage resistance of fused silica.The ion implantation accompanied with sputtering effect can passivate the sub-/surface defects to reduce the surface roughness and improve the surface quality slightly.The implanted oxygen ions can combine with the structural defects(ODCs and E′centers)to reduce the defect densities and compensate the loss of oxygen in fused silica surface under laser irradiation.Furthermore,oxygen ion implantation can reduce the Si-O-Si bond angle and densify the surface structure,thus introducing compressive stress in the surface to strengthen the surface of fused silica.Therefore,the laser induced damage threshold of fused silica increases and the damage growth coefficient decreases when ion energy up to30 ke V.However,at higher ion energy,the sputtering effect is weakened and implantation becomes dominant,which leads to the surface roughness increase slightly.In addition,excessive energy aggravates the breaking of Si-O bonds.At the same time,the density of structural defects increases and the compressive stress decreases.These will degrade the laser laser-damage resistance of fused silica.The results indicate that oxygen ion implantation with appropriate ion energy is helpful to improve the damage resistance capability of fused silica components.