Semiconductor device and etching mask used for fabricating the same

摘要

A semiconductor device (Fig. 6) is provided with a device formation region (50) formed by etching using a reticle (52; Fig. 5) as an etching mask. The device formation region is shaped to have at least two curved portions having different radii (R1, R2) being encircled with an insulation layer (59), so that radiated light is not converged to a single point inside the device formation region by light reflection on the inner edge of the insulation layer. Unwanted etching away of portions of gate electrodes (56, 58) is thereby avoided.