Automated SEM nanoprobe tool

Patent metadata

Field	Value
Publication number	US-9805910-B1
Application number	US-201514696122-A
Country	US
Kind code	B1
Filing date	Apr 24, 2015
Priority date	Mar 14, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

Aspects of the present disclosure provide an apparatus comprising a primary beam column configured to direct a primary beam of energetic particles onto a location of interest on a sample containing one or more integrated circuit structures, a detector configured to produce a signal in response to detection of secondary charged particles generated as a result of an interaction between the primary beam of energetic particles and the location of interest, and a signal processor coupled to the detector configured to measure the transient behavior of generation of the secondary charged particles from the signal produced by the detector, and a characterizing module configured to characterize the location of interest by comparing the measured transient behavior to a predetermined reference transient behavior. The detector has a response that is fast enough to detect a transient behavior of generation of the secondary charged particles.

First claim

What is claimed is:

1. An apparatus, comprising:
a primary beam column configured to direct a primary beam of energetic particles onto a location of interest on a sample containing one or more integrated circuit structures, wherein the primary beam column is configured to direct the primary beam to a next location of interest after each transient emission of secondary charged particles that is triggered by irradiation of the location of interest by the primary beam;
a detector configured to produce a signal in response to detection of secondary charged particles generated as a result of an interaction between the primary beam of energetic particles and the location of interest, wherein the detector has a response that is fast enough to obtain three or more measurements within about 10 ns or less during a measurement interval; and
a signal processor coupled to the detector configured to measure behavior of generation of the secondary charged particles from the signal produced by the detector; and
a characterizing module configured to characterize the location of interest by comparing the three or more measurements to a predetermined reference behavior of secondary charged particles versus time for a non-defective reference area.

2. The apparatus of claim 1 , wherein the primary beam of energetic particles is a beam of electrons.

3. The apparatus of claim 1 , wherein the secondary charged particles are secondary electrons.

4. The apparatus of claim 1 , wherein the primary beam of energetic particles is a beam of electrons and wherein the secondary charged particles are secondary electrons.

5. The apparatus of claim 1 , wherein the detector has a time resolution of about 2 ns or better.

6. The apparatus of claim 1 , further comprising a filter configured to reduce or remove a component of a signal corresponding to backscattered energetic particles from the primary beam.

7. The apparatus of claim 1 , wherein the primary beam column includes one or more deflectors configured to direct the primary beam to different locations on the sample.

8. The apparatus of claim 7 , wherein the primary beam column is configured to focus the beam to a beam spot at the location of interest and to direct the primary beam to the location of interest with sufficient accuracy that that more than about 80%, of a beam spot of the primary beam lands on location of interest.

9. The apparatus of claim 7 , wherein the primary beam column is configured to focus the primary beam to a spot size of about 100 nanometers or less.

10. The apparatus of claim 1 , further comprising a sample stage configured to retain the sample and a scanning mechanism configured to translate the sample in one or more directions.

11. The apparatus of claim 1 , wherein the signal processor is configured to generate three or more successive images of a region of the sample from a signal from the detector containing the location of interest and measure a transient behavior by comparing the signal value at the location of interest for the three or more successive images.

12. The apparatus of claim 1 , wherein the a signal processor is configured to generate an image of a region of the sample from a signal from the detector containing the location of interest and measure a transient behavior by analyzing the signal for adjacent pixels within the image at location of interest.

13. The apparatus of claim 1 , wherein the three or more measurements include 3, 4, 5, 6, 7, 8, 9, or 10 measurements.

14. The apparatus of claim 1 , wherein the three or more measurements include between 3 and 100 measurements.

15. The apparatus of claim 1 , wherein the three or more measurements include between 3 and 1000 measurements.

16. The apparatus of claim 1 , wherein the measurement interval is between about 1 nanosecond and about 200 nanoseconds in duration.

17. The apparatus of claim 1 , wherein the measurement interval is between about 10 nanosecond and about 100 nanoseconds in duration.

18. A method, comprising:
directing a primary beam of energetic particles from a primary beam column onto a location of interest on a sample containing one or more integrated circuit structures, wherein the primary beam is directed to a next location of interest after each transient emission of secondary charged particles that is triggered by irradiation of the location of interest by the primary beam;
detecting secondary charged particles generated as a result of an interaction between the primary beam of energetic particles and the location of interest with a detector;
measuring a behavior of generation of the secondary charged particles, wherein three or more measurements are obtained within about 10 ns or less over the course of a measurement interval; and
characterizing the location by comparing the three or more measurements to a predetermined reference behavior of secondary charged particles versus time for a non-defective reference area.

19. The method of claim 18 , wherein the primary beam of energetic particles is a beam of electrons.

20. The method of claim 18 , wherein the secondary charged particles are secondary electrons.

21. The method of claim 18 , further comprising directing the primary beam of energetic particles onto a next location of interest on the sample.

22. The method of claim 18 , wherein measuring a transient behavior includes generating two or more successive images of a region of the sample from a signal from the detector containing the location of interest and comparing the signal value at the location of interest for the two or more successive images.

23. The method of claim 18 , wherein measuring a transient behavior includes generating an image of a region of the sample from a signal from the detector containing the location of interest and analyzing the signal for adjacent pixels within the image at location of interest.

24. The method of claim 18 , wherein the three or more measurements include 3, 4, 5, 6, 7, 8, 9, or 10 measurements.

25. The method of claim 18 , wherein the three or more measurements include between 3 and 100 measurements.

26. The method of claim 18 , wherein the three or more measurements include between 3 and 1000 measurements.

27. The method of claim 18 , wherein the measurement interval between about 1 nanosecond and about 200 nanoseconds in duration.

28. The method of claim 18 , wherein the measurement interval between about 10 nanosecond and about 100 nanoseconds in duration.

29. A non-transitory computer-readable medium having computer executable instructions embodied therein, the computer executable instructions being configured to implement a method when executed, the method comprising:
directing a primary beam of energetic particles from a primary beam column onto a location of interest on a sample containing one or more integrated circuit structures, wherein the primary beam is directed to a next location of interest after each transient emission of secondary charged particles that is triggered by irradiation of the location of interest by the primary beam;
detecting secondary charged particles generated as a result of an interaction between the primary beam of energetic particles and the location of interest with a detector;
measuring a behavior of generation of the secondary charged particles, wherein three or more measurements are obtained within about 10 ns or les

Assignees

• Kla-Tencor Tech Corp
• Kla Tencor Corp

Inventors

• Trease David
• Sears Christopher M

Classifications

• H01J2237/24585

  Other variables, e.g. energy, mass, velocity, time, temperature · CPC title

• G01N23/2251

  using incident electron beams, e.g. scanning electron microscopy [SEM] · CPC title

• H01J37/263 Primary

  Contrast, resolution or power of penetration · CPC title

• H01J37/256

  using scanning beams · CPC title

• G01N23/22

  by measuring secondary emission from the material · CPC title