| 摘要 |
PURPOSE:To prevent damage of a silicon oxide group thin film being a vibrating part of a resonator by adding a process laminating a silicon nitride thin film to both faces of a silicon substrate being a support of the piezoelectric thin film resonator. CONSTITUTION:After a silicon nitride group thin film 11 is formed in a thickness of several thousands of Angstrom on both faces of a silicon substrate 10 having a Miller index of (100) by the CVD method, a silicon oxide thin film 12 is formed in the range of several mum - several tens of mum by the RF magnetron sputter method. Then a square window 13 is provided to the other silicon nitride group thin film through etching by using phosphoric acid, and the silicon substrate 10 is subjected to anisotropic etching through a PED liquid by taking said silicon nitride group thin film as a mask. The silicon oxide group thin film is not damaged because of the presence of the silicon nitride group thin film 11 in this case. The silicon nitride group thin film is removed through etching, if required, by using phosphoric acid. Thus, the piezoelectric thin film resonator with high Q is manufactured. |
