Method, a non-transitory computer-readable medium, and/or an apparatus for determining whether to order a mask structure

• US 10,599,046 B2
• Filed: 05/23/2018
• Issued: 03/24/2020
• Est. Priority Date: 06/02/2017
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Seongjong
• Primary Examiner(s): Aisaka, Bryce M
• Application Number:
  US15/987,238
• Publication Number:
  US 20180348641A1
• Time in Patent Office: 671 Days
• Field of Search: 716 52
• CPC Class Codes: G03F 1/22 Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G03F 7/70508 Data handling in all parts of the microlithographic apparatus, e.g. handling pattern data for addressable masks or data transfer to or from different components within the exposure apparatus
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: G03F 7/70641 Focus
• CPC Class Codes: G06F 2111/10 Numerical modelling
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G06F 30/3323 using formal methods, e.g. equivalence checking or property checking

Abstract

A method for determining whether to order a mask structure using a processor may include acquiring a simulation result of an EUV pattern layout, determining a correlation parameter (CP), generating a predicted wafer process window, and determining the mask structure is suitable for ordering based on the CP and the predicted wafer process window. The processor may determine the CP based on a weighting value and a simulated depth of focus (DOF), a simulated energy latitude (EL), and simulated line-LER area and LER-width parameters in the simulation result. The CP may indicate a correlation between the simulation result of the EUV pattern layout and an actual wafer result of the EUV pattern layout. The predicted wafer process window may be generated using the processor based on the CP. The predicted wafer process window may indicate whether the actual wafer result of the EUV pattern layout will include a patterning defect.

Claims

1. A method for determining whether to order a mask structure using a processor, the method comprising:

acquiring a simulation result of an extreme ultraviolet (EUV) pattern layout,

the simulation result including a simulated depth of focus (DOF), a simulated energy latitude (EL), a simulated line-edge roughness (LER) area parameter that is less than or equal to a first threshold, and a simulated LER width parameter that is less than or equal to a second threshold,

the simulated LER area parameter indicating a roughness of one or more area features in the simulation result of the EUV pattern layout,

the simulated LER width parameter indicating a roughness of one or more line features in the simulation result of the EUV pattern layout;

determining a correlation parameter (CP) using the processor based on the simulated DOF, the simulated EL, the simulated LER area parameter, the simulated LER width parameter, and a weighting value for the simulation result,

the CP indicating a correlation between the simulation result of the EUV pattern layout and an actual wafer result of the EUV pattern layout;

generating a predicted wafer process window using the processor based on the CP, the predicted wafer process window indicating whether the actual wafer result of the EUV pattern layout will include a patterning defect; and

determining the mask structure is suitable for ordering based on the CP and the predicted wafer process window.

2. The method of claim 1, wherein

the simulated LER area parameter is a stochastic edge placement error (SEPE) band space that is less than or equal than the first threshold,

the simulated LER width parameter is a SEPE band width that is less than or equal to the second threshold.

3. The method of claim 2, wherein the determining the CP includes calculating an EpPix value according to Equation 1 below:

EpPix={(1+w_i^a+w_ii^b)−

(e,f)}×

(1+w_iii^c+w_iv^d)} 

 

[Equation 1]

wherein, in Equation 1,

a is a focus center of the simulated DOF,

b is a dose center of the simulated EL,

c is the SEPE band space,

d is the SEPE band width,

w_i, w_ii, w_iii, and w_iv are components of the weighting value, and

(e,f) is an exposure-focus compensation factor.

4. The method of claim 3, wherein the generating the predicted wafer process window includes generating a prediction of a focus exposure metric (FEM) using the processor based on the EpPix value.

5. The method of claim 4, wherein the generating the prediction of the FEM includes generating a predicted FEM margin map.

6. The method of claim 5, wherein

the generating the prediction of the FEM includes generating the predicted FEM margin map to include a first focus region, a second focus region surrounding the first focus region, a third focus region surrounding the second focus region, and a fourth focus region surrounding the third focus region,

the generating the predicted wafer process window includes at least one of,

in response to the EpPix value being greater than a first value and less than or equal to a second value, predicting the patterning defect not occur in the first focus region to the fourth focus region or the patterning defect occurs at the fourth focus region,

in response to the EpPix value being greater than the second value and less than or equal to a third value, predicting the patterning defect occurring in at least one of the third focus region and the fourth focus region,

in response to the EpPix value being greater than the third value and less than or equal to a fourth value, predicting the patterning defect occurring in at least one of the second focus region, the third focus region, and the fourth focus region, and

in response to the EpPix value being greater than a fourth value, predicting the patterning defect occurs in at least one of the first focus region, the second focus region, the third focus region, and the fourth focus region.

7. The method of claim 6, wherein

the first value is 0,

the second value 10,

the third value 20, and

the fourth value is 30.

8. The method of claim 3, wherein the exposure-focus compensation factor (e,f) is based on an empirical model.

9. The method of claim 8, wherein the exposure-focus compensation factor (e,f) is in a range of about 1 to about 10.

10. The method of claim 1, wherein the acquiring the simulation result of the EUV pattern layout includes generating the simulation result based on a pre-optical-proximity-correction layout (pre-OPC layout) and calibrated models.

11. The method of claim 1, wherein the weighting value w is based on an empirical model.

12. The method of claim 11, wherein the weighting value w is in a range of about 1 to about 10.

13. The method of claim 1, wherein the simulation result of the EUV pattern layout includes a simulated anchor pattern and a simulated semi-isolated pattern.

14. The method of claim 1, further comprising:

forming a revised EUV pattern layout by adjusting a feature in the EUV pattern layout in response to a value of the of the CP being greater than a desired value;

acquiring a revised simulation result of the revised EUV pattern layout,

the revised simulation result including a revised simulated DOF, a revised simulated EL, a revised simulated LER area parameter that is less than or equal to the first threshold, a revised simulated LER width parameter that is less than or equal to the second threshold, and a revised weighting value;

determining a revised CP using the processor based on the revised simulated DOF, the revised simulated EL, the revised simulated LER area parameter, the revised simulated LER width parameter, and the revised weighting value,

the revised CP indicating a correlation between the revised simulation result of the revised EUV pattern layout and an actual wafer result of the revised EUV pattern layout;

generating a revised predicted wafer process window based on the revised CP, the revised predicted wafer process window indicating whether the actual wafer result of the revised EUV pattern layout will include the patterning defect; and

determining the mask structure is suitable for ordering based on the revised CP and the revised predicted wafer process window.

15. The method of claim 14, wherein

the revised simulated LER area parameter is a revised stochastic edge placement error (SEPE) band space that is less than or equal than the first threshold,

the revised simulated LER width parameter is a revised SEPE band width that is less than or equal to the second threshold,

the determining the revised CP includes calculating an EpPix value according to Equation 1 below:

EpPix={(1+w_i^a+w_ii^b)−

(e,f)}×

(1+w_iii^c+w_iv^d)} 

 

[Equation 1]

wherein, in Equation 1,

a is a focus center of the revised simulated DOF,

b is a dose center of the revised simulated EL,

c is the revised SEPE band space,

d is the revised SEPE band width,

w_i, w_ii, w_iii, and w_iv are components of the revised weighting value, and

(e,f) is a revised exposure-focus compensation factor.

16. A method for manufacturing an EUV mask, the method comprising:

performing the method of claim 1; and

ordering the mask structure in response to a value of the CP being less than a desired value.

17. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a processor, cause the processor to perform operations for determining whether to order a mask structure using an electronic apparatus, the operations including:

acquiring a simulation result of an extreme ultraviolet (EUV) pattern layout using the electronic apparatus,

the simulation result including a simulated depth of focus (DOF), a simulated energy latitude (EL), a simulated line-edge roughness (LER) area parameter that is less than or equal to a first threshold, and a simulated LER width parameter that is less than or equal to a second threshold;

determining a correlation parameter (CP) using the electronic apparatus based on the simulated DOF, the simulated EL, the simulated LER area parameter, the simulated LER width parameter, and a weighting value for the simulation result,

the CP indicating a correlation between the simulation result of the EUV pattern layout and an actual wafer result of the EUV pattern layout;

generating a predicted wafer process window using the electronic apparatus based on the CP, the predicted wafer process window indicating whether the actual wafer result of the EUV pattern layout will include a patterning defect; and

determining the mask structure is suitable for ordering based on the CP and the predicted wafer process window.

18. An apparatus for determining whether to order a mask structure, the apparatus comprising:

a memory; and

a processor coupled to the memory,

the processor, in response to executing instructions received from the memory, being configured to determine a correlation parameter (CP), based on a simulated depth of focus (DOF), a simulated energy latitude (EL), a simulated line-edge roughness (LER) area parameter, a simulated LER width parameter, and a weighting value,

the simulated DOF, the simulated EL, the simulated LER area parameter, the simulated LER width parameter being based on a simulation result of an extreme ultraviolet (EUV) pattern layout,

the CP indicating a correlation between the simulation result of the EUV pattern layout and an actual wafer result of the EUV pattern layout,

the processor being configured to generate a predicted wafer process window based on the CP, the predicted wafer process window indicating whether the actual wafer result of the EUV pattern layout will include a patterning defect, and

the processor being configured to determine the mask structure is suitable for ordering based on the CP and the predicted wafer process window.

19. The apparatus of claim 18, wherein

the simulated LER area parameter is a stochastic edge placement error (SEPE) band space that is less than or equal than a first threshold,

the simulated LER width parameter is a SEPE band width that is less than or equal to a second threshold, and

the processor is configured to determine the CP by calculating an EpPix value according to Equation 1 below:

EpPix={(1+w_i^a+w_ii^b)−

(e,f)}×

(1+w_iii^c+w_iv^d)} 

 

[Equation 1]

wherein, in Equation 1,

a is a focus center of the simulated DOF,

b is a dose center of the simulated DOF,

c is the SEPE band space,

d is the SEPE band width,

w_i, w_ii, w_iii, and w_iv are components of the weighting value, and

(e,f) is an exposure-focus compensation factor.

20. The apparatus of claim 19, wherein the processor is configured generate a predicted wafer process window as a focus exposure metric (FEM) based on the EpPix value.