Patent ID: 7474001

Claim:
A device for characterizing an etching process, the device comprising: an array of via regions formed by at least an etching process; wherein the array of via regions includes: a first via region associated with a first common via size and a first common via density; a second via region associated with a second common via size and a second common via density; a third via region associated with a third common via size and a third common via density; a fourth via region associated with a fourth common via size and a fourth common via density; wherein: the first common via density is smaller than the second common via density; the first common via density is equal to the third common via density; the third common via density is smaller than the fourth common via density; the second common via density is equal to the fourth common via density; wherein: the first common via size is equal to the second common via size; the first common via size is smaller than the third common via size; the third common via size is equal to the fourth common via size; the second common via size is smaller than the fourth common via size.