2D simulation of under-mask penetration in 4H-SiC implanted with Al(+) ions

In this work under-mask penetration of Al(+) ions implanted in 4H-SiC is investigated by computer simulation based on the Monte-Carlo binary collision approximation (MC-BCA). Results indicate that a small fraction of ions, implanted normal to a (0001) 4H-SiC wafer (8 degrees off-axis towards the {11-20}), is scattered and become channeled in the < 1120 > directions perpendicular to the < 0001 > axis. Due to this phenomenon, doped regions with concentration <= 10(-4) of the peak value, may extend laterally for a few mu m below the edge of a SiO(2) mask.