Lithography method and lithography mask

#The invention lies in the integrated technology field. More specifically, the invention relates to a lithography method for patterning layers during the fabrication of integrated circuits, and to a mask suitable for use in the lithography process.

#Lithography methods, which are based in particular on photolithography processes, are used for fabricating integrated circuits, in particular for fabricating interconnects for the wiring of integrated circuits.

#Interconnects of this type are usually incorporated in insulator layers seated directly, or with the interposition of a metal layer, on a substrate containing the integrated circuits. Substrates of this type are usually formed of silicon layers, and the insulator layers are usually formed of oxide layers, preferably silicon oxides.

#FIG. 1 is a schematic illustration of a configuration for carrying out the lithography method according to the invention;

#FIG. 2 is a schematic illustration of a mask for carrying out the method according to the invention, the mask being a binary mask;

#FIG. 3 is a schematic illustration of a mask for carrying out the method according to the invention, the mask being a halftone phase mask; and

#Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen an exemplary embodiment of a configuration for carrying out the lithography method according to the invention for exposing a photosensitive layer. Such processes are used during the fabrication of integrated circuits.

#The photosensitive layer, in the particular case, is a resist layer 1. The resist layer 1 is applied for example on an insulator layer 2, which is seated directly, or with the interposition of a metal layer, on a substrate 3 containing integrated circuits. The substrate 3 is preferably composed of silicon. The insulator layer 2 is preferably composed of a silicon oxide. Interconnects are incorporated in the insulator layer 2. Trenches and contact holes are etched in for the purpose of fabricating the interconnects according to a predetermined pattern. Metal is subsequently deposited into the trenches and contact holes.

#The trenches and contact holes are made in the insulator layer 2 by means of an etching process, preferably by means of a plasma etching process. For this purpose, at least one resist mask having a hole pattern corresponding to the trenches and contact holes is fabricated from the resist layer 1 bearing on the insulator layer 2. Trenches and contact holes are made by etching through the holes in the resist mask.