Method for reducing layout printability effects on semiconductor device performance
View Patent ↗A printability simulation is performed on a mask layout over a range of lithography process conditions. A layout configuration capable of inducing functional or parametric failure in a semiconductor device is identified in the mask layout. A test structure representative of the identified layout configuration is obtained. A design of experiment is associated with the test structure. The design of experiment is defined to investigating effects of variations of one or more layout attributes in the test structure. Multiple instance of the test structure are fabricated on a wafer according to the design of experiment. Electrical performance characteristics of the fabricated test structures are measured. Based on the measured electrical performance characteristics, one or more layout attributes of the test structure capable of causing functional or parametric failure are determined.
1. A method of reducing layout printability effects on semiconductor device performance, comprising:
performing a printability simulation on a mask layout over a range of lithography process conditions;
identifying a layout configuration in the mask layout that is operable to induce functional or parametric failure in a semiconductor device;
obtaining a test structure that is representative of the identified layout configuration, wherein a design of experiment is associated with the test structure, the design of experiment is defined to investigate effects of variations of one or more layout attributes in the test structure;
fabricating multiple instances of the test structure on a wafer according to the design of experiment;
measuring one or more electrical performance characteristics of the fabricated test structures; and
based on the measured electrical performance characteristics, determining one or more layout attributes of the test structure that are operable to cause functional or parametric failure.
2. A method as recited in claim 1 , further comprising:
changing a layout configuration of a semiconductor device based on the one or more layout attributes of the test structure operable to cause functional or parametric failure.
3. A method as recited in claim 2 , wherein changing the layout configuration of the semiconductor device' includes performing Resolution Enhancement Techniques (RET) or Optical Proximity Corrections (OPC).
4. A method as recited in claim 2 , wherein changing the layout configuration of the semiconductor device includes altering design parameters of the layout configuration.
5. A method as recited in claim 2 , wherein changing the layout configuration of the semiconductor device includes altering fabrication parameters for fabricating the semiconductor device.
6. A method as recited in claim 1 , wherein determining the one or more layout attributes of the test structure that are operable to cause functional or parametric failure includes quantifying an impact on semiconductor device performance due to variation of the one or more layout attributes according to the design of experiment associated with the test structure.
7. A method as recited in claim 1 , wherein determining the one or more layout attributes of the test structure that are operable to cause functional or parametric failure includes performing a further printability simulation on test structure layouts to quantify contributions of printability to semiconductor device performance.
8. A method as recited in claim 1 , wherein determining the one or more layout attributes of the test structure that are operable to cause functional or parametric failure includes performing fabrication process splits to determine an impact of the one or more layout attributes on semiconductor device performance.
9. A method as recited in claim 8 , wherein the fabrication process splits include varying focus parameters, exposure parameters, etch parameters, or a combination thereof for fabricating the test structures.
10. A method for reducing semiconductor device performance variability and yield loss, comprising:
performing a printability simulation on a semiconductor device mask layout to identify a critical layout configuration;
developing a test structure to emulate the identified critical layout configuration;
fabricating a test wafer to include multiple instances of the test structure, wherein each instance of the test structure represents a variation in one or more layout attributes of the test structure;
measuring one or more electrical performance characteristics of each test structure instance fabricated on the test wafer;
processing the measured electrical performance characteristics to determine one or more layout attributes of the test structure that are operable to cause functional or parametric failure; and
based on the determined layout attributes of the test structure that are operable to cause functional or parametric failure, identifying a design change, a process change, or a combination thereof to reduce functional or parametric failure of the identified critical layout configuration in the semiconductor device.
11. A method as recited in claim 10 , wherein the printability simulation includes decomposing a fabrication process impact on a mask layout feature into a sum of independent contributions.
12. A method as recited in claim 11 , wherein the independent contributions include defocus and exposure dependencies, critical dimension (CD) effects on dense and isolated lines, resist effects, etch effects, mask error and misalignment effects, or a combination thereof.
13. A method as recited in claim 10 , wherein the critical layout configuration represents a local region of a mask layout having one or more feature geometries that are susceptible to printability deficiency causing adverse electrical performance.
14. A method as recited in claim 10 , wherein the test structure is defined as an active device to emulate the geometric layout and electrical performance of an active device associated with the critical layout configuration.
15. A method for defining a semiconductor device design and fabrication process window with respect to electrical performance, comprising:
obtaining a test structure from a library of test structures defined to emulate critical layout configurations known to be sensitive to printability effects prevalent in semiconductor device mask layouts;
fabricating a test wafer to include multiple instances of the test structure, wherein each instance of the test structure represents a variation in one or more attributes of the test structure;
measuring electrical performance characteristics of each test structure instance fabricated on the test wafer; and
processing the measured electrical performance characteristics to identify unacceptable electrical performance of the test structure as a function of variation in the test structure attributes.
16. A method as recited in claim 15 , further comprising:
developing the library of critical layout configuration data by performing a printability simulation on a mask layout over a range of lithography process conditions.
17. A method as recited in claim 15 , wherein the critical layout configuration represents a local region of a mask layout having feature geometries that are susceptible to fabrication and lithographic problems.
18. A method as recited in claim 15 , wherein the test structure is defined as an active device to emulate the geometric layout and electrical performance of an active device associated with a critical layout configuration.
19. A method as recited in claim 15 , further comprising:
fabricating multiple test wafers according to split lots, wherein a wafer associated with each split lot is subjected to a variation in one or more fabrication processes.
20. A method as recited in claim 19 , wherein the variation in one or more fabrication processes includes varying focus parameters, exposure parameters, etch parameters, or a combination thereof.