Method of manufacturing a semiconductor device with metallization layers interconnected by tungsten plugs

Abstract

Method of making a semiconductor device, in which method a first layer of silicon oxide ( ) is deposited on a surface ( ) of a silicon body ( ), which layer is then provided with contact windows ( ) within which semiconductor zones ( ) formed in body and conductor tracks ( ) of non-crystalline silicon formed on the surface are exposed. On the first layer of silicon oxide a first metallization layer is formed, comprising conductor tracks ( ) which are in contact with the semiconductor zones ( ) and conductor tracks ( ) within the contact windows ( ). The first metallization is then covered with a second layer of silicon oxide ( ) which is provided with contact windows ( ) within which the conductor tracks ( ) of the first metallization are exposed. Then, successively, an adhesion layer ( ) is deposited, the contact windows ( ) are filled with tungsten plugs ( ), and a second metallization layer is formed comprising conductor tracks in contact with the tungsten plugs. The conductor tracks ( ) of the first metallization layer are formed in a tungsten layer, and a layer consisting only of titanium nitride deposited as the adhesion layer ( ). Due to said choice of material, the connections between the conductor tracks of the first and the second metallization layer only show small mutual differences in contact resistance.