Single-wafer processing: opportunities and challenges

As we approach the 0.25-μm technology node and 300-mm wafer manufacturing, the industry is challenged to develop new thermal processing tools to replace traditional large-batch furnaces. The most technically challenging process for practical single-wafer implementation is thick oxidation (e.g., for device isolation). In general, the tradeoff between process uniformity, yield and throughput, for each thermal process, will be reflected in the single-wafer vs. minibatch configuration of these tools. The last bastion of large batch processing will probably be wet immersion cleanups, which are less sensitive to the “device- and wafer-scaling pressures”. However, the migration of thermal processing away from large batches will exert “logistical pressure” on the associated cleanups to follow suit. Additional motivations for single-wafer processing are discussed