Patent ID: 8264235
Filing Date: 2012-09-11
Classification: G01R,H01L

Abstract:
1. A test structure comprising: at least two devices under test, both including a first electrical device resistance in a non-defect state or a second electrical device resistance in a defect state, the first electrical device resistance being higher than the second electrical device resistance, wherein the devices under test are connected in parallel to a first test contact pad via a first conducting line and connected in parallel to a second test contact pad via a second conducting line, wherein respective first test resistors are connected in series between the respective devices under test and either the first or second conducting line, the first test resistors having known respective electrical test resistances, such that a total electrical resistance between the first and second test contact pads is indicative of the number of devices under test, wherein the test structure further comprises respective second test resistors connected in series between the respective devices under test and the first or second conducting line, wherein a current flow between the first and second test contact pads is measured at a given voltage between the first and second test contact pads, wherein a number of devices under test, which have an electrical device resistance indicating a defect state, is determined from a measured test-quantity value, wherein a particular device under test is found such that a current flow corresponding to the particular device under test is the largest from a subset of devices under test of the test structure, wherein the current flow corresponding to the particular device under test is smaller than the measured current flow, and wherein an identifier of the respective device under test is stored or output, wherein a difference value is generated by subtracting the current flow corresponding to the particular device under test from the measured current flow, and wherein the finding of the particular device under test is repeated using the difference value, until the generated difference value reaches zero.