Diagnostics and troubleshooting of High Density Plasma Process

Introduction and motivation. This work presents results of electrical failure analysis and troubleshooting in an automotive ASIC. An unusual pattern of yield drop-out at sort test occurred suddenly on product which has been in manufacturing for years; no other products were affected by the problem. The pattern indicated strong wafer odd-even effect within a batch with up to 20% yield loss on the “bad” wafers and donut-shaped on the yield maps. Such wafers considered as underperforming for this particular automotive application and could not be sold to the customers. Therefore the gross yield dropped down to 49%. The failure analysis and 8D team were launched immediately to tackle the problem.