Grid distortion correction

Abstract

A method for operating a charged particle optics device, comprising: using the charged particle optics device to scan a sample including a series of positions with a charged particle beam to generate scanning data; changing the setting of at least one charged particle optics parameter of the charged particle optics device for each position, wherein the at least one charged particle optics parameter affects the charged particle optics grid distortion of the scanning data; and compensating for the charged particle optics grid distortion based on the changed setting of the at least one charged particle optics parameter.

Claims

1. A method for operating a charged particle optical device, Using the charged particle optical apparatus, a sample including a series of positions is scanned with a charged particle beam to generate scanning data, The setting of at least one charged particle optical parameter of the charged particle optical apparatus is changed for each position, wherein the at least one charged particle optical parameter affects the charged particle optical grid distortion of the scanning data. Compensating for the charged particle optical grid distortion based on the modified setting of at least one of the charged particle optical parameters, A method that includes this.

2. The method according to claim 1, wherein the at least one charged particle optical parameter includes a voltage focus parameter that contributes to determining the focus of the beam on the sample.

3. The method according to claim 2, wherein the voltage focus parameter corresponds to a potential applied to the stage of the charged particle optics configured to support the sample.

4. The method according to any one of claims 1 to 3, wherein the at least one charged particle optical parameter includes a magnetic focus parameter that contributes to determining the focus of the beam on the sample.

5. The method according to claim 4, wherein the magnetic focus parameter corresponds to the current passing through the magnetic coil of the charged particle optical apparatus.

6. The method according to any one of claims 1 to 5, wherein the at least one charged particle optical parameter includes an astigmatism corrector parameter that contributes to determining the cross-sectional shape of the beam.

7. The method according to claim 6, wherein the astigmatism corrector parameter corresponds to the potential applied to at least one electrode of the astigmatism corrector multipole.

8. The method according to any one of claims 1 to 7, wherein the compensation is performed by controlling the deflector of the charged particle optics to control the trajectory of the beam onto the sample based on the modified setting of the at least one charged particle optics parameter.

9. The method according to any one of claims 1 to 8, wherein the compensation is performed by correcting the scanning data based on the modified setting of the at least one charged particle optical parameter.

10. The method according to any one of claims 1 to 9, comprising measuring the effect of changing the at least one charged particle optical parameter on the charged particle optical grid distortion.

11. The method according to claim 10, wherein the compensation is performed using the results of the measurement.

12. The method according to claim 11, comprising at least one of interpolation and extrapolation of the results of the measurement.

13. The method according to any one of claims 1 to 12, wherein the compensation is performed using a charged particle optical model for predicting the effect of changing the at least one charged particle optical parameter on the charged particle optical grid distortion.

14. The method according to any one of claims 1 to 13, wherein the setting of a plurality of further charged particle optical parameters of the charged particle optical apparatus is kept substantially constant for each position.

15. The method according to any one of claims 1 to 14, further comprising compensating for the charged particle optical grid distortion based on information regarding the target structure on the sample.

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