PURPOSE: To suppress interconnection delay and to decrease the amount of cross talk at the same time, by providing a first insulating layer, which is formed on a semiconductor substrate, and providing a second insulating layer, which has a smaller dielectric constant than the dielectric constant of the first insulating layer.
CONSTITUTION: The outer surfaces of each interconnection 6 on a semiconductor substrate 4 are formed with insulating layers 5 and 7 in this interconnection structure. The dielectric constant of the insulating layer 7 is made smaller than the dielectric constant of the insulating layer 5. As the interconnection 6, an Al interconnection is used. As the insulating layer 5, an SiO2 layer, which has been actually used, is applied. As the insulating layer 7, a macromolecular material having a low dielectric constant such as, c.g., polytetrafluoroethylene (-[CF2CF2]-) or polyethylene, is applied. The dielectric constant of the SiO2 layer as the insulating layer 5 is 3.9. The dielectric constants of the polytetrafluoroethylene and the polyethylene as the insulating layer 7 are about 2.1 and 2.2, respectively. Therefore, even if the thickness of the insulating layer 5 beneath the interconnection is equal to the size between the interconnections or even if the size between the interconnections is smaller, the capacitance between the interconnections can be made smaller than the capacitance between the interconnections and the ground.
KOBAYASHI TOSHIO
MATSUI NORIO
| JPS6051262A | 1985-03-22 | |||
| JPS58123753A | 1983-07-23 | |||
| JPS60224229A | 1985-11-08 |