| 摘要 |
PROBLEM TO BE SOLVED: To provide a high Q factor by providing a substrate having a 1st dielectric constant and an insulating layer, which is positioned on the substrate and has a 2nd dielectric constant, making the 2nd dielectric constant lower than the 1st dielectric constant and positioning a conductive layer on the insulating layer. SOLUTION: A conductive layer 14 is positioned under conductive layers 11-13 adjacently to a lower face 18 of a substrate 15 and operated as the ground face of a semiconductor element 10. Besides, it is made almost parallel to the conductive layer 11 and a front face 17 of the substrate 15. When an insulating layer 16 is made of a low-loss material or its dielectric constant is lower than that of the substrate 15 and the thickness of the insulating layer 16 corresponds to the height joining the conductive layer 14 and the substrate 15, at the element 10, the conductive layer 11 is formed sufficiently wide, the impedance of the layer 11 is lowered, and the Q factor of the element 10 is increased. Since the dielectric constant of the insulating layer 16 is lower than that of the substrate 15, the entire dielectric constant between the conductive layers 11 and 14 can be lowered so that the Q factor of the element 10 can be increased. |
