How to extract defect densities from distribution

A technique is presented for representing a defect density, such as might be found on an integrated circuit. Distributions are a powerful tool for presenting defect distributions for test structures and are convenient for yield analysis and modeling. How the concept of distribution can be extended to give more information on the defects is shown. The power of this approach derives from its invariability to test stricture geometry, which enables direct comparison of data from different structures. It is explained how and why defect distributions measured on test structures can be related to those of other structures, i.e. integrated circuits. The mathematics are simple and lead to a defect density which can be expressed in units of defects per geometric factor per independent variable