METHOD AND SYSTEM FOR DETECTING AND CORRECTING PROBLEMATIC ADVANCED PROCESS CONTROL PARAMETERS
First Claim
1. A method for monitoring a feedback process control system, comprising the steps of:
- receiving a plurality of applied process control parameters associated with adjusting a semiconductor wafer process tool of a semiconductor device processing line;
measuring overlay error at a plurality of metrology target locations of a semiconductor wafer;
determining a set of measured parameters based on the measured overlay errors;
determining a set of revised process control parameters by comparing the applied process control parameters to the measured parameters;
determining at least one of a first set of statistical parameters associated with the measured parameters and a second set of statistical parameters associated with the revised process control parameters; and
displaying at least one of the first set of statistical parameters and the second set of statistical parameters.
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Accused Products
Abstract
The invention may be embodied in a system and method for monitoring and controlling feedback control in a manufacturing process, such as an integrated circuit fabrication process. The process control parameters may include translation, rotation, magnification, dose and focus applied by a photolithographic scanner or stepper operating on silicon wafers. Overlay errors are used to compute measured parameters used in the feedback control process. Statistical parameters are computed, normalized and graphed on a common set of axes for at-a-glance comparison of measured parameters and process control parameters to facilitate the detection of problematic parameters. Parameter trends and context relaxation scenarios are also compared graphically. Feedback control parameters, such as EWMA lambdas, may be determined and used as feedback parameters for refining the APC model that computes adjustments to the process control parameters based on the measured parameters.
62 Citations
30 Claims
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1. A method for monitoring a feedback process control system, comprising the steps of:
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receiving a plurality of applied process control parameters associated with adjusting a semiconductor wafer process tool of a semiconductor device processing line; measuring overlay error at a plurality of metrology target locations of a semiconductor wafer; determining a set of measured parameters based on the measured overlay errors; determining a set of revised process control parameters by comparing the applied process control parameters to the measured parameters; determining at least one of a first set of statistical parameters associated with the measured parameters and a second set of statistical parameters associated with the revised process control parameters; and displaying at least one of the first set of statistical parameters and the second set of statistical parameters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A nontransitory computer-readable storage medium having computer executable instructions for causing a computer-controlled apparatus to perform a method for monitoring a feedback process control system, comprising the steps of:
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receiving a plurality of applied process control parameters associated with adjusting a semiconductor wafer process tool of a semiconductor device processing line; measuring overlay error at a plurality of metrology target locations of a semiconductor wafer; determining a set of measured parameters based on the measured overlay errors, the measured parameters indicative of changes to the applied process control parameters for correcting the overlay errors; determining a set of revised process control parameters based on the applied process control parameters and the measured parameters; determining at least one of a first set of statistical parameters associated with the measured parameters and a second set of statistical parameters associated with the revised process control parameters; and displaying at least one of the first set of statistical parameters and the second set of statistical parameters. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification