METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE HAVING A POROUS DIELECTRIC LAYER AND AIR GAPS

The invention relates to a method of manufacturing a semiconductor device, comprising the provision of a dual damascene structure (20). This dual damascene structure (20) comprises a metal layer (1) with thereon a first dielectric layer (2) provided with a via (3). A second dielectric layer (5) is applied on the first dielectric layer (2) and is provided with an interconnect groove (6). The via (3) and the interconnect groove (6) are filled with a metal which forms a metal lead (9) with a top (10). The method further comprises the following steps:removing the second dielectric layer (5),applying a disposable layer (12) to the first dielectric layer (2) and the metal lead (9),planarizing the disposable layer (12) down to the top (10) of the metal lead (9),applying a porous dielectric layer (13) on the disposable layer (12),removing the disposable layer (12) through the porous dielectric layer (13) so as to form air gaps (14).According to the invention, the second dielectric layer (5) is used as a sacrificial layer in which the metal leads (9) are defined. By removing this layer (5) after defining the metal leads (9), the metal leads (9) stand out above the surface of the first dielectric layer (2). It is achieved by this that air gaps (14) can be formed next to the metal lead (9).