Creating and exploiting flexibility in Steiner trees

This paper presents the concept of flexibility-a geometric property associated with Steiner trees. Flexibility is related to the routability of the Steiner tree. We present an optimal algorithm which takes a Steiner tree and outputs a more flexible Steiner tree. Our experiments show that a net with a flexible Steiner tree increases its routability. Experiments with a global router show that congestion is improved by approximately 20%.