Optimal repair decisions for integrated circuits manufacturing

The sequential manufacturing process has been widely applied to the making of complicated integrated circuits (IC). The basic idea is to break an IC product line into a linear sequence of simple operations, and then, a final product with desired high complexity can be obtained by performing the individual operations step by step. To assure the quality of the in-process products, we may conduct a test after each operation. When an in-process product is fault-free, it will pass the test and be moved to the next operation. On the other hand, for a defective in-process product which fails the test, we have to make a decision to either scrap or repair it so that no fault propagates to later operations. The repair/scrapping decisions certainly affect the manufacturing cost. Our goal is to find a set of optimal repair decisions so that the total manufacturing cost per fault-free IC product is minimized. For an IC product line with n sequential operations, there are 2ⁿpossible decision combinations in total. In this paper, we introduce a dynamic programming approach with an algorithm of 0(n₂) complexity to solve the problem.