Method of establishing a structure of electrical interconnections on a silicon semiconductor device

Claim 1

A method of manufacturing a structure of electrical interconnections on a semiconductor device having a silicon substrate, this method comprising especially the following successive steps: producing contact zones at the surface of the semiconductor device, forming contact islands comprising at least one layer of silicide of a refractory metal, such as titanium or cobalt, covering the contact zones, forming on the assembly an isolating layer, in which contact openings are provided, in which at least parts of the surface of said contact islands are exposed, obtaining a metallic configuration of interconnections by first carrying out a step of at least partially filling the contact openings by localized elements of a refractory metal, such as tungsten or molybdenum, and by then covering the assembly with a metallic layer, which is then cut into a given configuration, parts of this metallic configuration covering the contact openings and being in electrical contact with said localized elements, characterized in that, before the isolating layer is formed, the contact islands are covered by a complementary metallic layer obtained by selective growth of tungsten or molybdenum, which is localized at said islands.

Claim 2

A method of manufacturing a structure of electrical interconnections on a semiconductor device having a silicon substrate, this method comprising especially the following successive steps: producing contact zones at the surface of the semiconductor device, forming contact islands comprising at least one layer of silicide of a refractory metal, such as titanium or cobalt, covering the contact zones, forming on the assembly an isolating layer, in which contact openings are provided, in which at least parts of the surface of said contact islands are exposed, obtaining a metallic configuration of interconnections by first carrying out a step of at least partially filling the contact openings by localized elements of a refractory metal, such as tungsten or molybdenum, and by then covering the assembly with a metallic layer, which is then cut into a given configuration, parts of this metallic configuration covering the contact openings and being in electrical contact with said localized elements, characterized in that, before the isolating layer is formed, the contact islands are covered by a complementary metallic layer obtained by selective growth of tungsten or molybdenum, which is localized at said islands.

Claim 4

A method as claimed in any one of claims 1 or 2, characterized in that, having chosen titanium as refractory metal for the formation of said layer of silicide, at its surface a layer of titanium nitride is formed which is used as a base for the selective growth of the complementary metallic layer.