Method and apparatus for combined particle location and removal

• US 6,356,653 B2
• Filed: 07/16/1998
• Issued: 03/12/2002
• Est. Priority Date: 07/16/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gale, Glenn W., Kim, Ben, Hevey, Maurice R., Sharrow, Joel M., Kern, Frederick W. Jr., Syverson, William A., Brigante, Jeffrey A.
• Primary Examiner(s): Mancuso, Joseph
• Assistant Examiner(s): Bali, Vikkram
• Application Number:
  US09/116,680
• Publication Number:
  US 20010043734A1
• Time in Patent Office: 1,335 Days
• Field of Search: 382/145, 382/147, 382/149, 382/151, 382/144, 382/141, 382/153, 438/4, 438/16, 438/795, 438/690, 438/14, 219/121.84, 15/15.1, 372/107, 348/86, 348/87, 348/125, 348/126
• US Class Current: 382/145
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

A method for removing one or more particles from a surface of an object is provided. The method has first and second steps of detecting and locating the one or more particles on the surface of the object. In a third step, focused energy is directed onto one or more of the detected particles to break a bond energy between the one or more particles and the surface thereby removing the one or more particles from the surface. In preferred variations of the method of the present invention, the object is a semiconductor wafer and the directed focused energy is in the form of a laser. Also provided is an apparatus for removing the plurality of particles from the surface of the object. The apparatus includes a detector for detecting and locating the plurality of particles on the surface of the object, and a laser for directing focused energy on one or more of the detected particles to break a bond energy between the one or more particles and the surface thereby removing the one or more particles from the surface.

Claims

1. A method for removing one or more particles from a surface of an object, the method comprising the steps of:

(a) detecting the one or more particles on the surface of the object, wherein said detecting is based on location of one or more of said particles, size of one or more of said particles, composition of said one or more of said particles or any combination thereof,

(b) locating the one or more particles on the surface of the object by generating location data in response to the detecting step, and

(c) directing focused energy to only the one or more located particles based upon their location for removing the located particles from the surface without altering the surface of the object.

2. The method of claim 1, wherein the object is a semiconductor wafer.

3. The method of claim 1, further comprising the step of determining the composition of the one or more located particles.

4. The method of claim 3, further comprising the step of adjusting the amount of energy directed at the detected particles based upon the detected size, composition, location of the particles or any combination thereof.

5. The method of claim 1, further comprising the steps of:

(i) determining whether the one or more particles located in step (b) are located in an area of interest, and

(ii) deciding to perform step (c) if it is determined that the one or more particles are located in an area of interest.

6. The method of claim 1, further comprising the steps of:

(i) determining whether the one or more particles located in step (b) are not located in an area of interest, and

(ii) deciding not to perform step (c) if it is determined that the one or more particles are not located in an area of interest.

7. The method of claim 6, wherein the object is a semiconductor wafer having sensitive regions, wherein the sensitive regions are not areas of interest.

8. The method of claim 7, wherein the sensitive regions are regions of photoresist mask.

9. The method of claim 1, further comprising the step of determining whether the one or more located particles have been removed after performing step (c).

10. The method of claim 9, further comprising the step of repeating step (c) and the determining step with focused energy of increasing power until it is determined that the one or more particles have been removed.

11. The method of claim 10, further comprising the step of overriding the repeating step if a predetermined number of directing steps have been performed without removing the one or more particles upon which the focused energy is directed.

12. The method of claim 1, further comprising the step of directing gas flow across the surface of the object for carrying away any removed particles.

13. The method of claim 12, wherein the gas is an inert or non-reactive gas.

14. The method of claim 13, wherein the inert gas is selected from a group consisting of helium, argon, and nitrogen.

15. An apparatus for removing one or more particles from a surface of an object, the apparatus comprising:

means for detecting the one or more particles on the surface of the object, wherein said means for detecting is based on location of one or more of said particles, size of one or more of said particles, composition of said one or more of said particles or any combination thereof, means for locating the one or more particles on the surface of the object which generates location data in response to the means for detecting, and

means for directing focused energy to only the one or more located particles based upon their location for removing the one or more located particles from the surface without altering the surface of the object.

16. The apparatus of claim 15, wherein the object is a semiconductor wafer.

17. The apparatus of claim 15, further comprising a means for determining the composition of the one or more located particles.

18. The apparatus of claim 17, further comprising means for adjusting the amount of focused energy directed at the one or more located particles based upon the determined composition of the one or more particles.

19. The apparatus of claim 15, further comprising:

means for determining whether the one or more located particles are located in an area of interest, and

means for deciding to direct focused energy on the one or more located particles if it is determined that the one or more located particles are located in an area of interest.

20. The apparatus of claim 15, further comprising:

means for determining whether the one or more located particles are not located in an area of interest, and

means for deciding not to direct focused energy on the one or more located particles if it is determined that the one or more located particles are not located in an area of interest.

21. The apparatus of claim 20, wherein the object is a semiconductor wafer having sensitive regions, wherein the sensitive regions are not areas of interest.

22. The apparatus of claim 21, wherein the sensitive regions are regions of photoresist mask.

23. The apparatus of claim 15, further comprising means for determining whether the one or more located particles have been removed after focused energy has been directed upon them.

24. The apparatus of claim 23, further comprising means for repeating the directing of focused energy and the determining if the one or more particles have been removed with focused energy of increasing power until it is determined that the one or more particles have been removed.

25. The apparatus of claim 24, further comprising means for overriding the repeating of the directing and determining steps if focused energy of increasing power has been applied a predetermined number of times without removing the one or more particles upon which the focused energy is directed.

26. The apparatus of claim 15, further comprising means for directing gas flow across the surface of the object for carrying away any removed particles.

27. The apparatus of claim 26, wherein the gas is an inert or non-reactive gas.

28. The apparatus of claim 27, wherein the inert or nonreactive gas is selected from a group consisting of helium, argon, and nitrogen.

29. The apparatus of claim 26, wherein the means for directing gas flow across the surface comprises:

a compressed gas source having an outlet directed towards the surface of the object,

a valve connected to the outlet, and

a processor for signaling the valve to open thereby directing the gas across the surface of the object.

30. The apparatus of claim 15, wherein the means for directing focused energy comprises:

a laser,

a three axis stage connected to the laser, and

a processor which is input with the location data for the particles from the means for locating, and outputs the three axis stage to take a position which directs the laser connected thereto to focus its energy onto the one or more particles.

31. The apparatus of claim 15, wherein the means for directing focused energy comprises:

stage,

a three axis laser connected to the stage, and

a processor which is input with the location data for the one or more particles from the means for locating, and outputs the three axis laser to take a position which directs the laser to focus its energy onto the one or more particles.

32. The apparatus of claim 15, wherein the means for detecting and locating the one or more particles on the surface of the object comprises:

a light source directed toward the surface,

a detector for detecting scattered light from the surface, and

a processor for correlating the detected scattered light from the surface into a map of the one or more particles size and location on the surface in at least two dimensions.

33. The apparatus of claim 32, wherein the map of the particles size and location on the surface is expressed in two dimensions.

34. The apparatus of claim 32, wherein the map of the particles size and location on the surface is expressed in three dimensions.