Implantation of Nitrogen Atoms in 4H-SiC Epitaxial Layers: A Comparison between Standard and Plasma Immersion Processes

This paper focuses on the formation of thin n(+)p junctions in p-type Silicon Carbide (SiC) epitaxial layers using two kinds of Nitrogen implantations. The standard beam ion implantations and PULSION (TM) processes were performed at two distinct energies (700 eV and 7 keV), and the subsequent annealing was held at 1600 degrees C in a resistive furnace specifically adapted to SiC material. No measurable electrical activity was obtained for both implantations performed at 700 eV, due to some outdiffusion of N dopants during the annealing despite a low surface roughness (rms similar to 1.4 rim) and no residual damage detected by RBS/C. A higher sheet resistance was measured in plasma-implanted samples at 7 keV (in comparison with beam-line implanted samples), which is partly related to N outdiffusion. The profiles of N atoms beam-implanted at 7 keV are not affected by the annealing. The corresponding electrical activation is fully completed.