摘要 |
The manufacture of a semiconductor device, for example a MOSFET of the trench-gate type of an IGBT, includes the steps of: forming at a surface (10a) of a semiconductor body (10) a first mask (53) having a window (53a), forming a localised region (15b) to improve the blocking/breakdown characteristics by introducing dopant (62) into a first area of the body via the window (53a), and thermally diffusing the localised region (15b) to a greater depth than the channel-accommodating region (15a) before providing a source region (13). A second mask (51) of complementary window pattern to the first mask (53) is formed by providing a differently-etchable material (51') in the first window (53a) and then etch-removing the first mask (53) while leaving the second mask (51) at the first area where the localised region (15b) is present. The source region (13) is formed by introducing dopant (63) of the opposite conductivity type into a second area at the complementary window (51a) while masking the first area with the second mask (51). The gate (11) is provided at the second area, adjacent to where a body region (15) provides the channel-accommodating region (15a). A source electrode (23) is provided after removing the second mask (51), so as to contact the opposite conductivity type regions (13, 15b) at the surface (10a). |