US Patent 8406028 Word line layout for semiconductor memory

A semiconductor memory includes first and second word lines. A first bit cell of a first type is coupled to a first one of a plurality of bit lines and has a first layout in which the first bit cell of the first type is coupled to the first word line with a first number of vias and to the second word line with a second number of vias. A first bit cell of a second type is coupled to a second one of the plurality of bit lines and has a second layout in which the first bit cell of the second type is coupled to the first word line with a third number of vias and to the second word line with a fourth number of vias. A load on the first word line is approximately equal to a load on the second word line.