Two-Dimensional Simulation of Undermask Penetration in 4H-SiC Implanted With Al⁺ Ions

Lateral undermask penetration of Al+ions implanted in 4H-SiC is investigated by computer simulation based on Monte Carlo binary collision approximation. Results show that a small fraction of ions, implanted normal to a (0001) 4H-SiC wafer miscut of 8° toward the {112̅0}, is scattered and become channeled in all the 〈112̅0〉 directions perpendicular to the 〈0001〉 axis, traveling long distances along these directions. Due to this phenomenon, channeling tails in ion distributions, with concentration ≤ 10-4of the peak value, can extend laterally for a few micrometers below the edge of a SiO2mask.