| 摘要 |
A semiconductor device comprises a buffer layer 16 of an i-InAlAs layer formed over an SI-InP substrate 14, insulating films 24, 36 of BCB formed over the buffer layer 16, and a coplanar interconnection including a signal line 52 and ground lines 54 formed over the insulating film 36, a cavity 46 is formed in the SI-InP substrate 14, the buffer layer 16 and the insulating film below the signal line 52, and pillar-shaped supports in the cavity 46 support the insulating films 34, 36 which are the ceiling of the cavity 46. |
