Method of manufacturing semiconductor device

摘要

A gate structure (4), an LDD region (6) and a sidewall (7) are provided in this order. Arsenic ions (8) are thereafter implanted into the upper surface of a silicon substrate (1) by tilted implantation. The next step is annealing for forming an MDD region (9) in the upper surface of the silicon substrate (1). The MDD region (9) and the gate structure (4) do not overlap one another in plan view. Further, the MDD region (9) formed into a depth shallower than that of the LDD region (6) is higher in concentration than the LDD region (6). Thereafter a source/drain region (11) higher in concentration than the MDD region (9) is provided by vertical implantation into a depth greater than that of the LDD region (6).