STUDY ON WAFER EDGE TEST WITH OPTIMIZED TEST SOLUTION

With the increase of the process complexity, the layered problem of stack film on wafer edge, especially on ugly dice (incomplete dice), is becoming more and more serious, and ultimately affect the test yield. Therefore, improving the wafer edge process becomes more and more important to enhance the yield and test stability. On the other hand, we need to optimize the test scheme to bypass the ugly dice or to improve the tolerance of the ugly dice. This paper will focus on the test optimization. Several approaches will be discussed, and some corresponding suggestions for improvement are put forward.