Evaluating k-values for low-k materials after damascene integration: Method and results

This work discusses a method for measuring k-values of low-k films after integration in damascene structures. The experimental results are obtained from 90nm 1/2 pitch single damascene structures on low-k materials with intrinsic k-values ranging between 2.2 and 3. The measurement technique is discussed in detail with a focus on the accuracy, limitation of the method, impact of low-k damage and applicability for smaller dimensions.