3 September 1998 Feedforward recipe selection control design software
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One method to achieve lower process variance is through inter-process feedforward control. There are two problematic issues associated with feedforward recipe adjustment: (1) there is noise in the measurement tool and adjusting for inaccurate measurements could increase the variance; and (2) it is difficult to alter one parameter in a manufacturing process without worsening other key parameters. The first issue is addressed by integrating statistics theory into the controller design. One way to solve the second issue is to constrain the controller to select a recipe form a finite set of pre-qualified recipes. We call this feedforward recipe selection control (FRSC). Each recipe in FRSC has a unique adjustment and, by definition of pre-qualified, every recipe will give acceptable values for all other key characteristics. The goal of this paper is to guide the reader through a complete FRSC design. The modeling data set is from an industrial CD patterning processes. Simulation of FRSC implementation shows a standard deviation reduction of 16 percent. We also derive a re-centering methodology order to place more integrated circuits into the fastest speed grade. Our simulation doubled the number of ICs in this fastest speed grade.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Steve Ruegsegger, Steve Ruegsegger, Aaron Wagner, Aaron Wagner, James S. Freudenberg, James S. Freudenberg, Dennis S. Grimard, Dennis S. Grimard, "Feedforward recipe selection control design software", Proc. SPIE 3507, Process, Equipment, and Materials Control in Integrated Circuit Manufacturing IV, (3 September 1998); doi: 10.1117/12.324363; https://doi.org/10.1117/12.324363


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