Semiconductor processing module with integrated feedback/feed forward metrology
First Claim
1. An apparatus for processing a semiconductor wafer, comprising:
- a measuring tool for measuring a dimension of a structure on the wafer;
a first processing tool for performing a first process on the wafer using a first set of process parameter values;
a transfer mechanism for transferring the wafer between the measuring tool and the first processing tool;
a chamber for enclosing the transfer mechanism and allowing communication between the transfer mechanism, the measuring tool and the first processing tool in a clean environment; and
a processor configured to select the first set of process parameter values based on the measurement of the dimension;
wherein the measuring tool is for measuring a critical dimension (CD) of a target feature on the wafer;
wherein the chamber comprises;
a mainframe for mounting a plurality of processing tools, including the first processing tool;
a factory interface for housing the measurement tool and for mounting a wafer cassette; and
a transfer chamber between and in communication with the mainframe and the factory interface; and
wherein the transfer mechanism comprises a first robot for transferring the wafer between the measurement tool, the transfer chamber and the wafer cassette, and a second robot for transferring the wafer between the transfer chamber and the first processing tool.
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Abstract
A method and apparatus for processing a semiconductor wafer to reduce CD variation feeds back information gathered during inspection of the wafer to a previously visited processing tool and feeds forward information to adjust the next process the wafer will undergo. The inspection and processing are performed at a single processing module without exposing the wafer to ambient atmospheric conditions. Embodiments include removing a wafer from a wafer cassette, and measuring a dimension of a feature on the surface of the wafer, such as the feature'"'"'s CD using an optical measuring tool. A process, such as an etch process, is then performed on the wafer using a set of process parameter values, such as an etch recipe, selected based on the CD measurement, and the wafer is returned to a cassette. The CD measurements are also linked to photolithography adjustable parameters such as stepper focus and exposure settings. The linked information on focus and exposure is fed back to the previously visited photo cell so the stepper can be adjusted, either automatically or at the user'"'"'s discretion, to correct the deviation in following lots. In some embodiments, post-etch processing, such as ash stripping, wet cleaning and/or further CD measurement, are performed by the module before the wafer is returned to a cassette. All of the transfer and processing steps performed by the module are performed in a clean environment, thereby increasing yield by avoiding exposing the wafer to the atmosphere and possible contamination between steps. This feedback and feed-forward mechanism improves CD control by adjusting processing parameters for every wafer based on the wafer'"'"'s measured CD.
119 Citations
10 Claims
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1. An apparatus for processing a semiconductor wafer, comprising:
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a measuring tool for measuring a dimension of a structure on the wafer;
a first processing tool for performing a first process on the wafer using a first set of process parameter values;
a transfer mechanism for transferring the wafer between the measuring tool and the first processing tool;
a chamber for enclosing the transfer mechanism and allowing communication between the transfer mechanism, the measuring tool and the first processing tool in a clean environment; and
a processor configured to select the first set of process parameter values based on the measurement of the dimension;
wherein the measuring tool is for measuring a critical dimension (CD) of a target feature on the wafer;
wherein the chamber comprises;
a mainframe for mounting a plurality of processing tools, including the first processing tool;
a factory interface for housing the measurement tool and for mounting a wafer cassette; and
a transfer chamber between and in communication with the mainframe and the factory interface; and
wherein the transfer mechanism comprises a first robot for transferring the wafer between the measurement tool, the transfer chamber and the wafer cassette, and a second robot for transferring the wafer between the transfer chamber and the first processing tool. - View Dependent Claims (2, 3, 4, 5, 6, 10)
select a second set of process parameter values based on the measurement of the wafer dimension, and provide the second set of process parameter values to a previously visited processing tool.
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3. The apparatus of claim 1, wherein measuring tool optically measures the CD of the target feature.
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4. The apparatus of claim 3, wherein the target feature CD is measured using scatterometry or reflectometry.
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5. The apparatus of claim 1, wherein the first processing tool comprises an etcher, and the first process parameter values comprise an etch recipe.
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6. The apparatus of claim 1, wherein the measuring tool is further for aligning the wafer.
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10. The apparatus of claim 1, further comprising a particle monitor mounted to the factory interface and in communication with the transfer mechanism.
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7. An apparatus for processing a semiconductor wafer, comprising:
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a measuring tool for measuring a dimension of a structure on the wafer;
a first processing tool for performing a first process on the wafer using a first set of process parameter values;
a transfer mechanism for transferring the wafer between the measuring tool and the first processing tool;
a chamber for enclosing the transfer mechanism and allowing communication between the transfer mechanism, the measuring tool and the first processing tool in a clean environment; and
a processor configured to;
select the first set of process parameter values based on the measurement of the dimension;
control the transfer mechanism to transfer the wafer from the first processing tool to the measuring tool after the first process is performed on the wafer; and
control the measuring tool to re-measure the dimension of the wafer.
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8. An apparatus for processing a semiconductor wafer, comprising:
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a measuring tool for measuring a dimension of a structure on the wafer;
a first processing tool for performing a first process on the wafer using a first set of process parameter values, the first processing tool comprising an etcher and the first set of process parameter values comprising an etch recipe;
a transfer mechanism for transferring the wafer between the measuring tool and the first processing tool;
a chamber for enclosing the transfer mechanism and allowing communication between the transfer mechanism, the measuring tool and the first processing tool in a clean environment;
a processor configured to select the first set of process parameter values based on the measurement of the dimension;
wherein the measuring tool is for measuring a critical dimension (CD) of a target feature on the wafer;
wherein the chamber comprises a mainframe to which the etcher is mounted, a factory interface to which the measurement tool and a wafer cassette are mounted, and a transfer chamber between the mainframe and the factory interface; and
wherein the transfer mechanism comprises a robot for transferring the wafer between the measurement tool, the transfer chamber and the wafer cassette;
the apparatus further comprising a cleaning module mounted to the factory interface for cleaning the wafer;
wherein the processor is configured to control the transfer mechanism to transfer the wafer from the cassette to the measuring tool, to transfer the wafer from the measuring tool to the first processing tool after the CD of the target feature is measured, to transfer the wafer from the first processing tool to the cleaning module after the first process is performed on the wafer; and
to transfer the wafer from the cleaning module to the cassette after the wafer has been cleaned.
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9. An apparatus for processing a semiconductor wafer, comprising:
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a measuring tool for measuring a dimension of a structure on the wafer;
a first processing tool for performing a first process on the wafer using a first set of process parameter values;
a transfer mechanism for transferring the wafer between the measuring tool and the first processing tool;
a chamber for enclosing the transfer mechanism and allowing communication between the transfer mechanism, the measuring tool and the first processing tool in a clean environment; and
a processor configured to select the first set of process parameter values based on the measurement of the dimension;
wherein the chamber comprises a mainframe for mounting a plurality of processing tools;
wherein the first processing tool is mounted to the mainframe;
wherein the transfer mechanism comprises a robot; and
wherein the measuring tool is mounted to the mainframe.
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Specification