| 摘要 |
PURPOSE:To prevent undesired corrosion of the substrate due to acid, alkali or water or the like by coating the surface and the rear face of an Li2B4O7 single crystal substrate by a protecting film and using the acid, alkali or water or the like. CONSTITUTION:An SiO2 film 4 is formed on the surface of the Li2B4O7 single crystal substrate 1 by the RF sputtering method and the rear face is subject to pre-processing by a silane coupling agent, after a polyethylene solution is spin-coated, the polyethylene film 3 is formed by heating and drying the face. An aluminum film is vapor-deposited on the said SiO2 film 4 by the vacuum vapor-deposition method, photo resist is coated on the aluminum face and pre- baked, and exposure is applied by using a mask with the electrode pattern. An alakli solution is used to apply development, rinsed by the water and the said aluminum film is wet-etched by using the etching liquid being the mixture of HNO3 and HCLO4 to form the surface acoustic wave exciting electrode and the photo resist is eliminated by plasma ashing.
|
