Activation Energy for the Post Implantation Annealing of 1019 cm-3 and 1020 cm-3 Ion Implanted Al in 4H SiC

The activation energy for the electrical activation of 1x1019 cm-3 and of 1x1020 cm-3 ion implanted Al in 4H-SiC has been estimated. Ion implantation temperature and dose rate were in the range 430-500°C and around 1011 cm2s-1, respectively. Post implantation annealing temperatures varied between 1500 °C and 1950 °C. The annealing time per each annealing temperature was sufficiently long that the sheet resistance of the implanted layer could be equal to the stationary value at the applied annealing temperature. The Arrhenius plots of the room temperature sheet resistances with respect to the post implantation annealing temperatures featured an exponential trend for both the implanted Al concentrations. The activation energies of these plots are the activation energy for placing an implanted Al atom in a substitutional site, i.e. the electrical activation energy. Activation energies around 1 eV, equal within errors for the two implanted Al concentrations, were found.

Effect of Ion Implantation-Induced Defects on Leakage Current Characteristics of IEMOS

We investigated the relationship between ion implantation-induced defects and electrical characteristics, especially focusing on the leak failure rate in SiC IEMOSs and PN diodes. It was found that dislocation exists in each leakage point by analyzing identical leak-failed IEMOS by emission microscopy and refraction X-ray topography. The leak failure rate of the PN diodes and IEMOS was improved with an increase in the ion implantation temperature under the implantation and annealing conditions used in this experiment. It is considered that ion implantation-induced defects lead to an increase in leak failure rates, and also enable a decrease in leak failure rates by raising the implantation temperature up to 600 deg.C.

Fatigue behavior of Ti-6Al-4V alloy modified by plasma immersion ion implantation: temperature effect.

This research studied Ti-6Al-4V alloy behavior with two (2) different microstructure subjected to nitrogen addition by PIII treatment, with and without sample heating, under cyclic load. PIII conditions, at 390 °C, were DC voltage of 9.5 kV, frequency of 1.5 kHz and pulse of 40 μs. PIII conditions, with sample heating at 800 °C, were 7 kV, 0.4 kHz and 30 μs. Axial fatigue tests were performed on untreated and treated samples for resistance to fatigue comparison. The untreated Ti-6Al-4V had an annealed microstructure, PIII treatment at 390 °C resulted in a microstructure that has no nitride layer or diffusion zone. In the PIII treatment at 800 °C, the microstructure presented nitride layer and diffusion zone. Resistance to fatigue decreased with PIII treatments in both temperatures. At 390 °C, the treatment created deformation regions and cracks on surface due to nitrogen implantation that formed solid solution with titanium and imposed lattice strains on the crystal lattice. At 800 °C, bulk ductility decrease, increasing of αTi proportion in microstructure due to α case formation and the presence of a ceramic layer dropped fatigue resistance of Ti-6A-4V alloy.