Introduction of high tensile strain into Ge-on-Insulator structures by oxidation and annealing at high temperature

It is demonstrated in this work that a high temperature thermal process including oxidation and N2 annealing at 850 oC can provide tensile strain of ~0.58 % at maximum into Ge-on-Insulator (GOI) structures without any special patterning or external stressors. The different impacts of oxidation and annealing on tensile strain generation, surface roughness and crystal qualities in the GOI structures fabricated by Ge condensation and wafer bonding are systematically examined. Tensile strain of 0.47 % is achieved without severe thermal damages under the optimal thermal process condition, which indicates the high potential of the present method for improving the performance of GOI n-channel MOSFETs. The influence of thermal expansion mismatch between Ge and SiO2 are suggested as a possible physical origin of high amount of tensile strain into GOI structures.

Preparation of Fe0.8Mn1.54Ni0.66O4 Nano-Ceramics by Sol-gel auto combustion and N2 Annealing for High Reliable NTC Thermistor

Fe0.8Mn1.54Ni0.66O4 nano-ceramics have been successfully prepared by sol-gel auto combustion. The microstructure and phase of these samples was observed by using Scanning Electron Microscopy and X-Ray Diffraction. The diameters of Fe0.8Mn1.54Ni0.66O4 ceramic particles pre-fired at 800℃ range from 52 to 83nm. The powder sintered at above 1050℃ has the compact and uniform spinel structure. We have investigated the electrical characteristics of these thermistors at different sintering temperatures and concluded that the sample sintered at 1200℃ is sufficient to form the appropriate spinel phase. Moreover, the thermistor annealed for 72h at 450~550℃ in N2 atmosphere has the drift value of <0.7%.