| 摘要 |
<p>PURPOSE:To obtain a high degree of frequency adjusting accuracy by a method wherein a capacitor, on which capacity value can be varied, a semiconductor element constituting a composite semiconductor circuit and a piezoelectric vibrating element are provided on the same substrate by performing a trimming operation on a polysilicon fuse. CONSTITUTION:A composite semiconductor circuit is composed of the semiconductor element 100 formed on the silicon thin film 2 located on a sapphire substrate 1, the capacitor 300 having a polysilicon fuse electrically connected to the element 100, and the elastic surface wave type piezoelectric vibrating element 200 formed on the zinc oxide thin film 3 located on the sapphire substrate 1. The vibrating element is composed of the surface wave exciting electrode 201 consisting of an aluminum one-layer wiring and a reflector 202, and the capacitor 300 consists of a polysilicon fuse 301 and a capacitor 302 of two- layer polysilicon structure. As a result, the frequency adjustment for + or -1ppm or below can be performed.</p> |
