A Novel Advanced Process Control for Semiconductor Manufacturing: Dual Proximate Inverse System Feedback Control

Advanced process control (APC) is very important to improve throughput, yield and performance of products in modern semiconductor manufacturing. It is difficult for conventional APC to reduce error automatically and effectively. A novel anti-systematic-error APC: dual proximate inverse system feedback control (DIFC), which can perform better than classical inverse feedback control, is proposed. It can cooperate with other feedback APC or classical methods to decrease systematic error. Sufficient condition that makes DIFC asymptotically stable and convergent to target output is given and proved. DIFC is simulated using several virtual semiconductor tools, e.g. RTP, ion implanter and CMP tool. Different control laws and inverse system models are used in these simulations. The study shows that DIFC can deal with systematical error continuous (during manufacturing) step (after maintenance). DIFC do reduce these errors by several orders of magnitude rapidly.