Gregory A. Cherry

Control and Monitoring of Semiconductor Manufacturing Processes: Challenges and Opportunities

Abstract The semiconductor industry is going through a technology transition from 200mm to 300mm wafers to improve manufacturing efficiency and reduce manufacturing cost per chip. These technological changes present a unique opportunity to optimally design the process control systems for the next generation fabs. In this paper we first propose a hierarchical fab-wide control framework with the integration of 300mm equipment and metrology tools and highly automated material handling system. Relevant existing run-to-run technology is reviewed and analyzed in the fab-wide control context, process and metrology data monitoring are discussed with an example, and missing components are pointed out as opportunities for future research and development. Concluding remarks are given at the end of the paper.

Fisher Discriminant Analysis for Semiconductor Batch Tool Matching

Abstract We propose in this paper how Fisher discriminant analysis can be applied for differentiating classes of semiconductor data from different tools or chambers. The tool and chamber matching analysis can be useful not only from a process characterization standpoint, but also for identifying the proper fault detection and classification strategy. If the FDA analysis shows that the chambers or tools are not matched, it is likely that either preventive maintenance will be needed, or a separate fault detection and diagnosis model will be required for each tool or chamber. Alternatively, if the match fraction is large enough, a global model should be considered for monitoring a plurality of tools or chambers to reduce the model maintenance effort. Contribution analysis is also applied to identify variables responsible for tool mismatching.