SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING SUCH A DEVICE

摘要

A semiconductor device, for example an IC, having conductor tracks (3) of a metal (3) exhibiting a better conductance than aluminium, such as copper, silver, gold or an alloy thereof. The tracks are situated on an insulating layer (2) and are connected to a semiconductor region (1A) or to an aluminium conductor track by means of a metal plug (5), for example of tungsten, which is situated in an aperture (4) in the insulating layer (2). The bottom and walls of the aperture (4) are provided with an electroconductive material (6), such as titanium nitride, which forms a diffusion barrier for the metal (3). In accordance with the invention, the insulating layer (2) comprises a sub-layer (2A), which forms a diffusion barrier for the metal (3) and which extends, outside the aperture (4), throughout the surface of the semiconductor body (10). As a result, the conductor tracks (3) no longer have to be provided with a sheath serving as a diffusion barrier for the metal (3). The conductor tracks (3) may thus have a cross-section of very small dimensions, while the electric resistance will is still be sufficiently low. The same applies for any further conductor tracks (8), which may be present above the conductor tracks (3) and which are electrically insulated therefrom. Preferably, the electrically insulating sub-layer (2A) is situated approximately in the middle of the insulating layer (2). By virtue thereof, the contribution of the sub-layer (2A) to capacitances threatening the velocity of the IC is minimized. Suitable materials for the sub-layer (2A) are oxides, nitrides, fluorides and carbides, for example aluminium oxide, magnesium fluoride or silicon carbide. The insulating layers (2, 7, 11, 12) preferably comprise silicon dioxide.