DEVICE FOR PREVENTING INTENSITY REDUCTION OF OPTICAL SIGNAL, OPTICAL EMISSION SPECTROMETER, OPTICAL INSTRUMENT, AND MASS SPECTROMETER INCLUDING THE SAME

• US 20120120395A1
• Filed: 11/10/2011
• Published: 05/17/2012
• Est. Priority Date: 11/12/2010
• Status: Active Grant

• Current Assignee: Industry Academic Cooperation Foundation
• Original Assignee: Industry Academic Cooperation Foundation
• Inventors: HAHN, Jae Won
• Granted Patent: US 9,025,143 B2
• Time in Patent Office: Days
• US Class Current: 356/326
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0286 Constructional arrangements for compensating for fluctuations caused by temperature, humidity or pressure, or using cooling or temperature stabilization of parts of the device; Controlling the atmosphere inside a spectrometer, e.g. vacuum
• CPC Class Codes: G01J 3/443 Emission spectrometry
• CPC Class Codes: H01J 49/0422 for gaseous samples interfaces to gas chromatographs G01N30/7206
• CPC Class Codes: H01J 49/068 Mounting, supporting, spacing, or insulating electrodes
• CPC Class Codes: H05K 9/009 comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked

Abstract

A device for a device for preventing the intensity reduction of an optical signal, an optical emission spectrometer, an optical instrument, and a mass spectrometer including the same are provided. The device for preventing the intensity reduction includes a shielding filter which has a mesh structure capable of blocking RF electromagnetic waves radiated from a plasma field for a wafer processing, is installed in the front of an optical window of an optical emission spectrometer for measuring the plasma field from an emission spectrum image of the plasma field, and collects charging particles passing through the mesh.

Claims

1. A device for preventing the intensity reduction of an optical signal, comprising:

a shielding filter which has a mesh structure capable of blocking RF electromagnetic waves radiated from a plasma field for a wafer processing, is installed in the front of an optical window of an optical emission spectrometer for measuring the plasma field from an emission spectrum image of the plasma field, and collects charging particles passing through the mesh.

2. The device for preventing the intensity reduction of an optical signal of claim 1, wherein one shielding filter has an extension surface in a vertical direction to input and inflow paths of a plasma emission spectrum.

3. The device for preventing the intensity reduction of an optical signal of claim 1, wherein a plurality of shielding filters having an extension surface in a vertical direction to input and inflow paths of the plasma emission spectrum are continuously arranged according to the input and inflow paths of the plasma emission spectrum.

4. The device for preventing the intensity reduction of an optical signal of claim 3, wherein the plurality of shielding filters include hollow parts and crossing parts of the mesh having the same phase as each other.

5. The device for preventing the intensity reduction of an optical signal of claim 3, wherein the plurality of shielding filters include hollow parts and crossing parts of the mesh having different phases from each other.

6. The device for preventing the intensity reduction of an optical signal of claim 5, wherein the plurality of shielding filters have extension directions of linear elements configuring the mesh which are disposed to be different from each other.

7. The device for preventing the intensity reduction of an optical signal of claim 5, wherein the plurality of shielding filters have a regular phase difference according to the extension direction of the linear element configuring the mesh.

8. The device for preventing the intensity reduction of an optical signal of claim 5, wherein the plurality of shielding filters have mesh structures having different densities.

9. The device for preventing the intensity reduction of an optical signal of claim 1, further comprising:

a fixation frame which has a shape corresponding to a circumference of the shielding filter, is connected to the shielding filter, and assembled to the front end of the optical window of the optical emission spectrometer.

10. The device for preventing the intensity reduction of an optical signal of claim 9, wherein insertion grooves into which the shielding filter is inserted and fixed are formed at the inner portion of the fixation frame.

11. The device for preventing the intensity reduction of an optical signal of claim 9, wherein the fixation frame is contact-connected to one-side circumference of the shielding filter to restrict the shielding filter or pressurized toward the front end of the optical emission spectrometer.

12. The device for preventing the intensity reduction of an optical signal of claim 11, further comprising:

an insertion ring inserted between the front end of the optical emission spectrometer and the shielding filter and/or between the shielding filters with a spaced interval.

13. The device for preventing the intensity reduction of an optical signal of claim 12, the insertion ring is made of an elastic member.

14. An optical emission spectrometer for measuring plasma, comprising:

a shielding filter which has a mesh structure capable of blocking RF electromagnetic waves radiated from a plasma field for a wafer processing, is installed in the front of an optical window into which an emission spectrum of the plasma field is inputted, and collects charging particles passing through the mesh;

an optical system main body including a receiving lens receiving the plasma emission spectrum passing through the shielding filter, an aperture determining a size of the optical signal inputted to and/or outputted from the receiving lens, and a pinhole limiting the depth of focus of the optical signal passing through the receiving lens; and

an analyzer analyzing emission spectrum image of the plasma field by receiving the optical signal passing through the aperture and the pinhole from the optical system main body.

15. The optical emission spectrometer of claim 14, further comprising:

a protection window made of a transparent material and disposed between the receiving lens and the shielding filter.

16. The optical emission spectrometer of claim 14, further comprising:

a laser device irradiate a laser in a proceeding direction and an opposed direction of the optical signal in the optical system main body so that the receiving lens, the aperture, and the pinhole are aligned and controlled therebetween by matching a collecting position of the laser light and a measuring position of the plasma field.

17. An optical instrument comprising:

a shielding filter which has a mesh structure capable of blocking RF electromagnetic waves radiated from a plasma field for a wafer processing, is installed in the front of an optical window into which an emission spectrum of the plasma field is inputted, and collects charging particles passing through the mesh;

a lens receiving a plasma emission spectrum passing through the shielding filter; and

a light processing device making an image of an object or measuring physical parameters by reflecting, refracting, interfering, diffracting, and/or polarizing the optical signal passing through the lens.

18. A mass spectrometer comprising:

a shielding filter which has a mesh structure capable of blocking an RF electromagnetic wave radiated in a plasma field for a wafer processing and is installed in the front of an inlet of the analyzed gas to collecting the charging particles passing through the mesh;

an ionizer ionizing and accelerating the analyzed gas;

a separator separating ions accelerated by passing through the ionizer according to a mass; and

a detector detecting and measuring the separated ions through the separator.

19. A device for preventing the intensity reduction of an optical signal, comprising:

a plurality of positive electrode plates and negative electrode plates having concentric holes formed at the center thereof and alternately arranged so as to overlap with each other to collect charging particles passing through the holes.

20. The device for preventing the intensity reduction of an optical signal of claim 19, wherein the positive electrode plate and the negative electrode plate are insulated from each other by a nonconductor.

21. The device for preventing the intensity reduction of an optical signal of claim 20, wherein the nonconductor is configured by i) an insulation part inserted between the positive electrode plate and the negative electrode plate, ii) an anti-contamination part formed to be spaced apart from the positive electrode plate and the negative electrode plate with a regular interval, and iii) a connection part connecting the insulation part and the anti-contamination part, in order to prevent the positive electrode plate and the negative electrode plate from being current-conducted with each other by the contamination of the nonconductor surface due to the charging particles.

22. The device for preventing the intensity reduction of an optical signal of claim 19, wherein the electrode plate array is insulated from an external body by the nonconductor.

23. An optical emission spectrometer comprising:

i) a device for preventing the intensity reduction of an optical signal including a plurality of positive electrode plates and negative electrode plates having concentric holes formed at the center thereof and alternately arranged so as to overlap with each other to collect charging particles passing through the holes;

ii) an optical system body including a receiving lens into which the optical signal passing through the device for preventing the intensity reduction of the optical signal flows, a pinhole on which an image of the optical signal passing through the receiving lens is focused, an aperture installed between the pinhole and the receiving lens to determine a receiving angle, and a transfer optical system transferring the optical signal passing through the pinhole;

iii) an optical fiber transferring the optical signal passing through the optical system body to the analyzer; and

iv) a spectrum analyzer analyzing the optical signal collected through the optical fiber.

24. The optical emission spectrometer of claim 23, wherein the positive electrode plate and the negative electrode plate are insulated from each other by a nonconductor.

25. The optical emission spectrometer of claim 24, wherein the nonconductor is configured by i) an insulation part inserted between the positive electrode plate and the negative electrode plate, ii) an anti-contamination part formed to be spaced apart from the positive electrode plate and the negative electrode plate with a regular interval, and iii) a connection part connecting the insulation part and the anti-contamination part, in order to prevent the positive electrode plate and the negative electrode plate from being current-conducted with each other by the contamination of the nonconductor surface due to the charging particles.

26. The optical emission spectrometer of claim 23, wherein the electrode plate array is insulated from an external body by the nonconductor.

27. The optical emission spectrometer of claim 23, wherein sizes of inner concentric circles formed at the positive electrode plate and the negative electrode plate configuring the device for preventing the intensity reduction of an optical signal are determined according a receiving angle of the light.

28. The optical emission spectrometer of claim 23, wherein the positive electrode plate and the negative electrode plate are black-colored or black-processed with a conductive material, in order to prevent the scattering of light.

29. The optical emission spectrometer of claim 23, wherein a protection window disposed in the front of the receiving lens is separately formed at the device for preventing the intensity reduction of an optical signal, in order to prevent the contamination of the receiving lens.

30. The optical emission spectrometer of claim 23, further comprising:

a laser device connected to the optical fiber.

31. The optical emission spectrometer of claim 30, wherein the measuring position and the lens are aligned by matching a collected position of the laser light emitted from the laser device and a position of a measuring target.

32. A mass spectrometer comprising:

i) a device for preventing the intensity reduction of an optical signal of an analyzed sample including a plurality of positive electrode plates and negative electrode plates having concentric holes formed at the center thereof and alternately arranged so as to overlap with each other to collect charging particles passing through the holes;

ii) an ionizer ionizing and accelerating the analyzed sample;

iii) a separator separating accelerated ions according to a mass; and

iv) a detector detecting and measuring the separated ions.

33. The mass spectrometer of claim 32, wherein the positive electrode plate and the negative electrode plate are insulated from each other by a nonconductor.

34. The mass spectrometer of claim 33, wherein the nonconductor is configured by i) an insulation part inserted between the positive electrode plate and the negative electrode plate, ii) an anti-contamination part formed to be spaced apart from the positive electrode plate and the negative electrode plate with a regular interval, and iii) a connection part connecting the insulation part and the anti-contamination part, in order to prevent the positive electrode plate and the negative electrode plate from being current-conducted with each other by the contamination of the nonconductor surface due to the charging particles.

35. The mass spectrometer of claim 32, wherein the electrode plate array is insulated from an external body by the nonconductor.