Base Diffused Test Site Special
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
Rs (sheet resistivity) measurement is effected (on a tester) every working day in order to define Rs standards. These standards are control wafers issued from regular production. They are tested about ten times and compared with Rs reference wafers before becoming standards. The difficulty is to guarantee the Rs values of the standards and to simplify the procedure of their generation because of instability of tests using certain probes. The proposed solution is to generate wafers with both a silicon portion and a test site without interactions. The value of the standard is defined with test site measurements. The large areas of silicon allow good measurements with not sensitive to test site mapping. Such wafers are processed in two-week periods and used as a standard after a third mask contact opening and test.