MANUFACTURE OF SURFACE ACOUSTIC WAVE DEVICE

PURPOSE:To decrease generation of recessed parts by forming a resist mask projected in a convexed form in advance to a part where a recessed part is produced, using the resist mask to etch the metallic film and form electrodes in manufacturing a surface acoustic wave device used as a surface acoustic wave resonator or a surface acoustic wave filter. CONSTITUTION:After aluminum 11 is vapor-deposited on a crystal substrate 10, a positive photoresist 12 is coated on the aluminum 11. Then an ultraviolet ray is exposed via the photomask. A part 13 not subjected to ultraviolet ray exposure consists of plural stripes 14, 15 and 16. Projections 20, 21, 22, 23 are applied to stripes adjacent to the vicinity 17, 18, 19 of the tip of each stripe. Then the positive photoresist 12 is developed to remove the photo resist 12 exposed by the ultraviolet ray and the resist mask where the aluminum 11 for the part is exposed is obtained. The exposed aluminum 11 is etched by using the resist as a mask in the crystal substrate 10 and the resist mask is removed.