Patent ID: 6501534
Filing Date: 2002-12-31
Classification: G03F

Abstract:
A system for calibrating lithography system settings in semiconductor manufacturing, comprising:a stepper system adapted to generate a plurality of test structures on a substrate, the stepper system further comprising: an illumination source for exposing the substrate within the stepper system; an illumination filter for varying the illumination being exposed to the substrate; one or more lenses for directing and focusing the illumination onto the substrate; a mask/reticle containing a test structure thereon for exposing an image of the test structure on the substrate; and a stage for the placement of the substrate to be exposed; a focus control system for varying focus parameters within the stepper system; an exposure control system for varying exposure parameters within the stepper system; a developing system for developing an exposed substrate; a measurement system adapted to characterize the plurality of generated test structures, thereby generating test structure characterization data associated with the plurality of test structures; a first memory for collecting and retaining a base set of ideal test structure characterization data; a second memory for collecting and retaining the generated test structure characterization data from the measurement system; a third memory for collecting and retaining a plurality of focus and exposure conditions; and a processor operatively associated with the stepper system, the focus control system, the exposure control system, the measurement system, the first memory, the second memory, and the third memory, and operable to control the stepper system, focus control system, exposure control system and developing system to generate the plurality of test structures, wherein each of the test structures is associated with a unique focus and exposure condition, and further operable to compare the generated test structure characterization data to the ideal test structure characterization data, to determine an optimal focus and exposure condition based on the comparison of the plurality of the generated test structure characterization data to the ideal test structure characterization data, wherein the optimal focus and exposure condition is the focus and exposure condition associated with the generated test structure having characterization data that comprises a closest match to the ideal test structure characterization data, and to employ the determined optimal focus and exposure condition in the stepper system via the focus control system and the exposure control system, respectively.