This paper presents an analysis of the potential yield loss in FPGA due to random defects in metal layers. A proven yield model is adapted to target the FPGA interconnect layers in order to predict the manufacturing yield. Defect parameters from the 2003 SIA roadmap are used to investigate the trend in yield loss due to defects in interconnect layers in the future. It is shown that the low yield predicted for the 45nm technology node and beyond is a cause for concern. The potential impact on yield using two different approaches, namely redundant circuits and fault tolerant design, is also presented.