US Patent 7807480 Test cells for semiconductor yield improvement

A test cell for localizing defects includes a first active region, a second active region formed substantially parallel to the first active region, a third active region formed substantially parallel to the first and second active regions, a fourth active region formed between the first and second active regions, and a fifth active region formed between the second and third active regions. The fourth and fifth active regions are formed adjacent to opposite end portions of the second active region. The fourth and fifth active regions are also formed substantially perpendicular to the second active region.