Optimization of scanner throughput and imaging quality for a patterning process
AssigneeASML Netherlands B.V.
InventorsXingyue Peng, Duan-Fu Stephen Hsu
Life of this patent
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Abstract
A method for source mask optimization to increase scanner throughput for a patterning process is described. The method includes computing a multi-variable cost function of design variables that are representative of characteristics of the patterning process. The design variables may include (a) an illumination variable that is characteristic of an illumination system, and (b) a design layout variable that is characteristic of a design layout. The multi-variable cost function may be a function of a throughput of the patterning process. The method further includes reconfiguring the characteristics of the patterning process by adjusting the design variables until a predefined termination condition is satisfied.
Claims20
A method for determining a throughput of a patterning process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illumination system and projection optics, the method comprising:
- obtaining, using a hardware computer system, a physical dose, wherein the physical dose is indicative of an energy density received at the substrate through an open-frame mask accumulated through a specified exposure time;
- and
- computing, using the hardware computer system, the throughput as a function of the physical dose.
A non-transitory computer-readable medium having instructions therein, the instructions, when executed by a computer system, are configured to cause the computer system to at least:
- obtain a physical dose of a patterning process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illumination system and projection optics, wherein the physical dose is indicative of an energy density received at the substrate through an open-frame mask accumulated through a specified exposure time;
- and
- compute a throughput of the patterning process as a function of the physical dose.
A method for determining a throughput of a patterning process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illumination system and projection optics, the method comprising:
- obtaining a dose-to-clear value, wherein the dose-to-clear value is a minimum physical dose required to cause a uniform chunk of a resist in the substrate to develop;
- computing, by a hardware computer system, a physical dose or full-transmission dose based on the dose-to-clear value, wherein the physical dose is indicative of an energy density received from the illumination system at the substrate through an open-frame mask accumulated through a specified exposure time, and wherein the full-transmission dose is indicative of a dose received at the substrate through an open-frame mask and without any obscuration or apodization in the illumination system;
- and
- computing, by the hardware computer system, the throughput as a function of (a) the physical dose or full-transmission dose, and (b) one or more lithographic projection apparatus parameters.
A non-transitory computer-readable medium having instructions therein, the instructions, when executed by a computer system, are configured to cause the computer system to at least:
- obtain a dose-to-clear value of a patterning process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illumination system and projection optics, wherein the dose-to-clear value is a minimum physical dose required to cause a uniform chunk of a resist in the substrate to develop;
- compute a physical dose or full-transmission dose based on the dose-to-clear value, wherein the physical dose is indicative of an energy density received from the illumination system at the substrate through an open-frame mask accumulated through a specified exposure time, and wherein the full-transmission dose is indicative of a dose received at the substrate through an open-frame mask and without any obscuration or apodization in the illumination system;
- and
- compute a throughput of the patterning process as a function of (a) the physical dose or full-transmission dose, and (b) one or more lithographic projection apparatus parameters.
Dependencies are inferred from the claim text.