Concurrent measurement of critical dimension and overlay in semiconductor manufacturing
DCFirst Claim
1. A system that monitors and controls a semiconductor fabrication process comprising:
- a structure formed on at least a portion of a wafer matriculating through the fabrication process that facilitates concurrent measurement of one or more critical dimensions and overlay,a measurement system that concurrently measures one or more critical dimensions and overlay by mapping the wafer into one or more grids that comprises one or more locations on which a grating structure is formed; and
a control system operatively coupled to the measurement system and one or more fabrication components to selectively control one or more of the fabrication components or operating parameters of the fabrication components to mitigate overlay error and to bring critical dimensions within acceptable tolerances based upon one or more of the concurrent measurements taken by the measurement system.
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Litigations
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Reexamination
Accused Products
Abstract
A system and methodology are disclosed for monitoring and controlling a semiconductor fabrication process. One or more structures formed on a wafer matriculating through the process facilitate concurrent measurement of critical dimensions and overlay via scatterometry or a scanning electron microscope (SEM). The concurrent measurements mitigate fabrication inefficiencies, thereby reducing time and real estate required for the fabrication process. The measurements can be utilized to generate feedback and/or feed-forward data to selectively control one or more fabrication components and/or operating parameters associated therewith to achieve desired critical dimensions and to mitigate overlay error.
65 Citations
25 Claims
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1. A system that monitors and controls a semiconductor fabrication process comprising:
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a structure formed on at least a portion of a wafer matriculating through the fabrication process that facilitates concurrent measurement of one or more critical dimensions and overlay, a measurement system that concurrently measures one or more critical dimensions and overlay by mapping the wafer into one or more grids that comprises one or more locations on which a grating structure is formed; and a control system operatively coupled to the measurement system and one or more fabrication components to selectively control one or more of the fabrication components or operating parameters of the fabrication components to mitigate overlay error and to bring critical dimensions within acceptable tolerances based upon one or more of the concurrent measurements taken by the measurement system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A system that facilitates concurrent measurement of one or more critical dimensions and overlay during a semiconductor fabrication process via scatterometry comprising;
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one or more underlying gratings formed within an underlying layer of at least a portion of a wafer undergoing the semiconductor fabrication process that facilitates measurement of overlay by analyzing light reflected from the gratings; one or more overlying gratings formed over the underlying gratings on an overlying layer of at least a portion of the wafer that facilitates measurement of one or more critical dimensions by analyzing reflected electrons; and one or more logical grids mapped to the wafer comprising one or more locations in which the underlying and overlying gratings for use in concurrent measurements is formed. - View Dependent Claims (15, 16, 17)
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18. A system that facilitates concurrent measurement of one or more critical dimensions and overlay error during a semiconductor fabrication process via a scanning electron microscope (SEM) comprising:
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one or more features formed in a resist layer of at least a portion of a wafer undergoing the fabrication process that facilitates measurement of one or more critical dimensions by analyzing electrons from an electron beam directed at and reflected from at least the portion of the wafer; and one or more gratings formed under the features in a polysilicon layer of at least a portion of the wafer by mapping the wafer into one or more blocks comprising one or more locations in which the one or more gratings for use in the concurrent measurement is formed, portions of the gratings extending out from tinder the features facilitating a determination of overlay error by analyzing reflected electrons, the features are formed within an implant layer of a flash memory product.
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19. A method for monitoring and controlling a semiconductor fabrication process comprising:
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providing a plurality of wafers undergoing the fabrication process; mapping the plurality of wafers into one or more logical grids comprising one or more portions in which a grating structure for use in concurrent measurements is formed; concurrently measuring one or more critical dimensions and overlay in a wafer undergoing the fabrication process; determining if one or more of the critical dimensions are outside of acceptable tolerances; determining whether an overlay error is occurring; developing control data based upon one or more concurrent measurements when at least one of an overlay error is occurring and one or more of the critical dimensions fall outside of acceptable tolerances; and feeding forward or backward the control data to adjust one or more fabrication components or one or more operating parameters associated with the fabrication components when at least one of an overlay error is occurring and one or more of the critical dimensions fall outside of acceptable tolerances to mitigate overlay error and/or to bring critical dimension within acceptable tolerances. - View Dependent Claims (20, 21, 22)
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23. A system that monitors and controls a semiconductor fabrication process comprising:
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means for mapping one or more logical grid blocks to at least one wafer; means for forming at least one grain structure according to the one or more logical grid blocks associated with at least a portion of the wafer undergoing the fabrication process that facilitates concurrent measurements of one or more critical dimensions and overlay; means for directing at least one of light and electrons onto the structure; means for collecting light reflected from the structure; means for analyzing the reflected light to determine whether at least one of an overlay error is occurring and one or more critical dimensions full outside of acceptable tolerances; and means for adjusting one or more fabrication components or one or more operating parameters associated with the fabrication components when at least one of overlay error is occurring and one or more of the critical dimensions fall outside of acceptable tolerances to mitigate overlay error and/or to bring critical dimension within acceptable tolerances. - View Dependent Claims (24, 25)
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Specification