an engineering change order base cell module is disclosed along with some of its applications . the cell has an n well and p well , p + implant and n + implant regions , n well pick - up and p well pick - up regions , a first power supply line , and a second power supply line , wherein the eco base cell has a same configuration as a standard logic cell and is alterable in at least one metal layer for making one or more connections to form a functional logic cell .