ESD prevention in PRT SEM discharge

Abstract

This invention provides methods, computer programs, and devices for acting on the charge state of a sample. [Solution] The present invention relates in particular to a method for acting on the charge state of a sample, comprising delivering a charged particle beam onto a sample for the purpose of analyzing and / or processing the sample, wherein particles of a particle beam are accelerated onto the sample by a first accelerating voltage, thereby charging the sample; and delivering a charged particle beam onto a sample for the purpose of acting on the charge of the sample, wherein particles of a particle beam are accelerated onto the sample by a second, modified accelerating voltage which is at least 15% of the first accelerating voltage.

Claims

1. A method of acting on the charge state of a sample, Sending a charged particle beam onto the sample for the purpose of analyzing and / or processing the sample, wherein the particles of the particle beam are accelerated onto the sample by a first accelerating voltage, and as a result the sample is charged. Sending the charged particle beam N times onto the sample for the purpose of acting on the charge of the sample, wherein the particles of the particle beam are accelerated onto the sample by the second to (N+1) acceleration voltages, respectively, N is 2 or greater, The second acceleration voltage becomes at least 15% of the first acceleration. A method wherein the second acceleration voltage is different from the first acceleration.

2. The method according to claim 1, wherein the second acceleration voltage is lower than the first acceleration voltage.

3. The method according to either claim 1 or 2, wherein the analysis includes recording the X-ray beam generated in the sample by the particle beam.

4. The method according to any one of claims 1 to 3, wherein the first acceleration voltage is at least 1 kV, more preferably at least 3 kV, and most preferably at least 4 kV.

5. The method according to any one of claims 1 to 4, wherein the second acceleration voltage is at least 30%, preferably at least 40%, particularly preferably at least 50%, and most preferably at least 60% of the first acceleration voltage for analysis.

6. The method according to any one of claims 1 to 5, wherein the particle beam for the analysis has a particle current of at least 5 pA, preferably at least 1 nA, and most preferably at least 150 nA.

7. The method according to any one of claims 1 to 6, wherein the particle current during the analysis and / or processing of the sample is substantially equal to the particle current during the action of the charge on the sample.

8. The method according to any one of claims 1 to 7, wherein the acceleration voltage N is at least 30%, preferably at least 40%, particularly preferably at least 50%, very preferably at least 60%, and most preferably 70% of the (N-1) acceleration voltage.

9. The method according to any one of claims 1 to 8, wherein the acceleration voltage of N is at least 250 V lower than the acceleration voltage of (N-1), and / or the acceleration voltage of N is up to 4 kV lower than the acceleration voltage of (N-1).

10. The method according to any one of claims 1 to 9, wherein the N transmissions are performed continuously, and in the process, the acceleration voltage of each is reduced at least twice.

11. The method according to claim 10, wherein at least two of the aforementioned decreases are performed by the same absolute value in each case.

12. The method according to claim 10, wherein at least two of the reductions are performed such that the absolute value of the reduction follows a logarithmic profile.

13. The method according to any one of claims 1 to 12, wherein the particle beam is delivered onto the sample without interruption between at least two acceleration voltages.

14. The method according to any one of claims 1 to 13, wherein the action includes reducing the charge of the sample.

15. The method according to any one of claims 1 to 14, further comprising detecting at least one process parameter associated with the current charge state of the sample.

16. The method according to claim 15, wherein the second acceleration voltage is at least partially based on the at least one process parameter.

17. The aforementioned detection, Modulation of the aforementioned acceleration voltage, The method according to any one of claims 15 and 16, further comprising demodulating at least one of the process parameters.

18. The method according to any one of claims 15 to 17, further comprising delivering the particle beam onto the sample using an acceleration voltage that is at least partially based on a closed feedback loop that includes the at least one process parameter as an input variable.

19. The method according to claim 17 or 18, wherein the at least one process parameter is kept substantially constant in the time profile.

20. The method according to any one of claims 15 to 19, wherein the at least one process parameter is associated with the secondary electron yield SEY.

21. The method according to any one of claims 1 to 20, wherein scanning electron microscope (SEM) images are recorded upstream and / or downstream of the method.

22. To provide a conductive element, The method according to any one of claims 1 to 21, further comprising at least partially sending the charged particle beam onto the conductive element in order to emit secondary particles from the conductive element.

23. A method (400, 500, 800) that acts on the charge state of a sample, Prepare the scanning probe microscope (SPM) tip (420, 550, 820). To act on the aforementioned charged state, a conductive connection is formed between the sample and the tip of the SPM (440, 550). This includes delivering a particle beam onto the sample for the purpose of analyzing and / or processing the sample (460, 470, 540, 560), A method for forming the conductive connection (440, 550) based at least in part on the measured charge state and / or expected charge state of the sample.

24. A method (400, 500, 800) that acts on the charge state of a sample, Prepare the scanning probe microscope (SPM) tip (420, 550, 820). This includes forming a conductive connection between the sample and the SPM tip (440, 550) for the purpose of acting on the aforementioned charged state, The method is performed in a scanning probe microscope-scanning electron microscope combined device.

25. The method according to claim 23, wherein the method is performed in a scanning probe microscope-scanning electron microscope composite device.

26. The method according to claim 25, wherein the conductive connection is formed by bringing the SPM tip close to the surface of the sample (440, 550, 830, 840).

27. The method according to claim 26, wherein the approach is performed at least partially on the detection of at least one process parameter.

28. A method for monitoring the charge state of a sample, This includes detecting process parameters associated with the charge state of the sample, wherein the process parameters have been recorded by a scanning electron microscope (SEM), a scanning probe microscope (SPM), and / or an X-ray detector. The method described above is Determining the charge state of the sample based at least partially on the process parameters, A method further comprising: if the charge of the sample exceeds a predetermined charge threshold, initiating a method for acting on the charge state of the sample.

29. The method according to claim 28, wherein the determination is performed at least in part using a known relationship between the process parameters and the charge state of the sample.

30. The method according to any one of claims 28 and 29, wherein the determination is at least in part based on detecting an interaction between the tip of the SPM and the sample.

31. A computer program comprising code for performing the method described in any one of claims 1 to 30.

32. A device for acting on the charge state of a sample, Conductive elements, and / or particle beams of scanning electron microscopes (SEM), and / or X-ray detectors, A device comprising means for automatically performing the method described in any one of claims 1 to 30.

33. The device according to claim 32, further comprising means for controlling the distance between the conductive element and the sample and / or the acceleration voltage of the particle beam.

34. The device according to any one of claims 32 and 33, further comprising means for executing the computer program described in claim 31.

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