Method for manufacturing silicon carbide semiconductor element e.g. MOSFET, involves doping the channel region by performing ion implantation through openings of lower mask layer

摘要

The method involves applying a mask (20) on a substrate (10) made of silicon carbide. A lower masking layer (8) of mask is in contact with substrate. An upper mask layer (9) of mask is in contact with lower masking layer, and is made of material which is inert to chlorine trifluoride (ClF3)-containing gas. An electrode region in substrate is doped by performing ion implantation through openings of mask. Upper masking layer is removed after etching lower masking layer by ClF3-containing gas. A channel region is doped by performing ion implantation through openings of lower mask layer.