Perfect Free Zone Quality Determination
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
The main characterization for the material analysis is the quality determination of the silicon width where the circuit works. With the technique described in [*] the defect-free-zone is measured up to 7 mm for thick oxides. For thin oxides, the breakdown voltage limits depletion width. Thus, only a small defect-free zone (<7 mm) can be measured. On the other hand, new wafer products with a wide defect-free zone (>10 mm) are processed in the manufacturing lines. Therefore, we have to characterize the defect-free zone not only in terms of widths but also in terms of quality with the present invention, the defect-free zone quality can be determined up to 30 mm. The technique is the following: 1. Wafer process 1.1. Beveling method: the thickness is measured on a diameter at each centimeter.