| 摘要 |
PURPOSE:To improve the linearity of end parts of metallic reed-screen type electrodes and to improve electric characteristics of a surface acoustic wave device by improving the adhesion between a passivation layer and the metallic reed-screen type electrode layer without etching the metallic reed-screen type electrode layer with a developer for a resist mask. CONSTITUTION:The passivation layer 4 and a photoresist film 3 are formed on the metallic reed-screen type electrode layer 2 and the mask 3A is formed on the photoresist 3; and then the passivation layer 4 and metallic reed-screen type electrode layer 2 are etched successively through the mask 3A to form metallic reed-screen type electrodes. In this case, the metallic reed-screen type electrode layer 2 is not etched because of the passivation layer 2 and the adhesion between the passivation layer 4 and metallic reed-screen type electrode layer 2 is good, so an etchant is prevented from entering partially the gap between the passivation layer 4 and metallic reed-screen type electrodes 2A in their extension direction and the linearity of end parts of extending metallic reed-screen type electrodes 2A is improved. Further, the verticality of end parts (surface perpendicular to substrate 1) of the metallic reed-screen type electrodes 2A is improved.
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