Method and apparatus for connecting signal lines of multiple layers to certain contacts while preventing connections with other contacts

A method comprising:

• diffusing impurities in a surface of a substrate to form a plurality of diffusion lines;
• applying a first insulation layer on the surface of the substrate;
• applying a signal line layer comprising a first plurality of signal lines on the insulation layer;
• applying a first metal layer on the signal line layer;
• etching the first metal layer to provide a second plurality of signal lines, wherein the second plurality of signal lines include a first metallic material;
• applying a second metal layer on the first metal layer;
• etching the second metal layer to provide a third plurality of signal lines, wherein the third plurality of signal lines include a second metallic material;
• forming a first plurality of contacts connecting the plurality of diffusion lines to (i) a first set of the second plurality of signal lines, or (ii) a first set of the third plurality of signal lines;
• and
• forming a second plurality of contacts connecting a first set of the first plurality of signal lines to a second set of the third plurality of signal lines,
• wherein a first set of the second plurality of signal lines are formed such that each signal line in the first set of the second plurality of signal lines comprises first portions and second portions, wherein the first portions extend towards and are not connected to the second plurality of contacts, and wherein the first portions are not parallel to the second portions.