Systems and methods for determining systematic defects

A non-transitory computer-readable medium that stores a set of instructions which when executed perform a method executed by the set of instructions comprising:

• transforming elements of a circuit under test into scan cells, wherein transforming the elements comprises enabling a scan input and a scan output for the elements;
• forming a first scan chain comprising a first plurality of scan cells of a first cell type, wherein forming the first scan chain comprises connecting the scan output of a first scan cell to the scan input of a second san cell;
• determining that the first cell type not to be a suspect for a systematic defect;
• swapping, one scan cell of the first scan chain with another scan cell of a second scan chain, wherein the another scan cell is of a second cell type;
• and
• testing, after the swapping, the first scan chain to determine a cell-dependent defect.

An apparatus for determining a systematic defect in a circuit under test, the apparatus comprising:

• a memory storage;
• and
• a processing unit coupled to the memory storage, wherein the processing unit is operative to:
• form a first scan chain comprising a first plurality of scan cells, wherein each scan cell of the first plurality of scan cells of the first scan chain are of a first cell type;
• determine whether the first cell type is a suspect for a systematic defect;
• mask, in response to determining that the first cell type is not a suspect for the systematic defect, the first plurality of scan cells of the first scan chain;
• form a second scan chain comprising a second plurality of scan cells, wherein the second scan chain comprises of at least one scan cell of a second cell type;
• and
• determine that the second scan chain is a suspect for the systematic defect.