Apparatuses for and methods of monitoring optical radiation parameters for substrate processing operations

• US 7,482,576 B2
• Filed: 05/03/2006
• Issued: 01/27/2009
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: KLA-Tencor Corporation
• Inventors: Hunt, Dean, Beers, Andrew, Freed, Mason L., MacDonald, Paul D., Mundt, Randall S.
• Primary Examiner(s): Lee; John R
• Application Number:
  US11/430,315
• Publication Number:
  US 20060289763A1
• Time in Patent Office: 1,000 Days
• Field of Search: 738/659, 438/16, 702/184, 702/122, 250/239
• US Class Current: 250/239
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0204 Compact construction
• CPC Class Codes: G01J 1/4228 arrangements with two or more detectors, e.g. for sensitivity compensation

Abstract

One or more problems related to processing workpieces using processes that involve optical radiation are presented along with solutions to one or more of the problems. One embodiment of the invention comprises a sensor apparatus for collecting optical radiation data representing one or more process conditions used for processing a workpiece. In a further embodiment, the sensor apparatus is also configured for measuring data other than optical radiation.

Claims

1. A sensor apparatus for measuring optical radiation from within a process chamber, the process chamber being configured for processing workpieces with a process that involves optical radiation, the sensor apparatus comprising:

a substantially planar window, the window being substantially transparent to the optical radiation;

at least one sensor for measuring the optical radiation, the at least one sensor having an electrical conductivity response to exposure to the optical radiation, the at least one sensor having a dark resistance of no more than about 2 mega-ohms and a fully illuminated resistance of no less than about 10,000 ohms;

electrical conductors forming electrical connections for the at least one sensor;

a base joined with the window so as to substantially encapsulate the at least one sensor and the electrical conductors therebetween; and

a controller electrically connected with the electrical conductors whereby the controller is configured to send and receive electrical signals via the electrical conductors, the controller being supported by the base.

2. The sensor apparatus of claim 1, wherein the window is configured for at least one of:

optical radiation attenuation, optical radiation wavelength transmission selectivity, and optical radiation reflectivity reduction.

3. The sensor apparatus of claim 1 further comprising a thin film optical interference filter applied to the window.

4. The sensor apparatus of claim 1 further comprising a filler material provided between the window and the base so as to substantially eliminate one or more voids therebetween.

5. The sensor apparatus of claim 1, wherein the base comprises a silicon wafer.

6. The sensor apparatus of claim 1, wherein the base comprises a flatpanel substrate, or a lithography mask substrate.

7. A sensor apparatus for measuring optical radiation from within a process chamber, the process chamber being configured for processing workpieces with a process that involves optical radiation, the sensor apparatus comprising:

a substantially planar window, the window being substantially transparent;

a substantially planar photosensitive sheet having an electrical conductivity responsive to exposure to optical radiation, the sheet having a dark resistance of no more than about 2 mega-ohms and a fully illuminated resistance of no less than about 10,000 ohms;

electrical conductors applied to the photosensitive sheet so as to form ohmic contacts to the photosensitive sheet, the electrical conductors being arranged so as to define nodes of a crosspoint network of regions of the sheet;

a controller electrically connected with the electrical conductors so as to send and receive electrical signals via the electrical conductors;

a base joined with the window so as to substantially encapsulate the photosensitive sheet and the electrical conductors therebetween; and

one or more additional sensors other than optical radiation sensors disposed between the base and the window.

8. The sensor apparatus of claim 7, wherein the window is configured so as to be capable of at least one of:

optical radiation attenuation,

optical radiation wavelength transmission selectivity, and

optical radiation reflectivity reduction.

9. The sensor apparatus of claim 7 further comprising a thin film interference filter applied to the window.

10. The sensor apparatus of claim 7 wherein the one or more additional sensors include a temperature sensor, charge sensor, electric field sensor, magnetic field sensor, heat flux sensor or ion energy sensor disposed between the base and the window.

11. The sensor apparatus of claim 7, wherein the window comprises quartz, fused silica, sapphire, diamond, aluminum oxide, or diamond-like carbon.

12. The sensor apparatus of claim 7, wherein the window is substantially transparent to optical radiation with wavelengths ranging from about 0.2 um to about 0.9 um.

13. The sensor apparatus of claim 7, wherein the photosensitive sheet is responsive to optical radiation with wavelengths ranging from about 0.2 um to about 0.9 um.

14. The sensor apparatus of claim 7, wherein the photosensitive sheet comprises a material selected from the group consisting of cadmium sulfide, cadmium selenide, selenium, germanium, silicon, amorphous silicon, cadmium telluride, and gallium arsenide.

15. The sensor apparatus of claim 7, wherein the workpieces are semiconductor wafers for manufacturing semiconductor devices, the sensor apparatus is substantially circular, and the sensor apparatus has a diameter substantially equal to the diameter of the semiconductor wafers.

16. The sensor apparatus of claim 7, wherein the workpieces are flatpanel display substrates for manufacturing flat panel displays, the sensor apparatus has length and width dimensions substantially equal to the length and width dimensions of the flat panel display substrates.

17. The sensor apparatus of claim 7, wherein the sensor apparatus has length and width dimensions substantially equal to the length and width dimensions of a lithography substrate for manufacturing lithography masks for manufacturing semiconductor devices.

18. The sensor apparatus of claim 7, wherein the photosensitive material has a dark resistance of no more than about 0.5 mega-ohms and a fully illuminated resistance of no less than about 30,000 ohms.

19. The sensor apparatus of claim 7 wherein the electrical conductors comprise a plurality of output electrical conductors and a plurality of input electrical conductors;

the controller being connected with the output electrical conductors and with the input electrical conductors, the controller being capable of applying electrical signals to the output electrical conductors, the controller being capable of measuring electrical signals received from the input electrical conductors;

whereby, application of electrical signals to the output electrical conductors and measurement of electrical signals at the input electrical conductors provide sufficient information to derive the optical radiation measurements.

20. The sensor apparatus of claim 7 wherein the optical radiation is generated from a plasma process.

21. The sensor apparatus of claim 7 wherein the optical radiation is generated from an ultraviolet light source.

22. An apparatus comprising:

a plurality of output electrical conductors;

a plurality of input electrical conductors;

a plurality of optical radiation sensors capable of presenting optical radiation measurements as electrical resistance, each of the sensors having a dark resistance of no more than about 2 mega-ohms and a fully illuminated resistance of no less than about 10,000 ohms, each of the sensors being connected with one of the output electrical conductors and one of the input electrical conductors so as to form an array of crosspoint connections; and

a controller connected with the output electrical conductors and with the input electrical conductors, the controller being configured so as to apply electrical signals to the output electrical conductors, the controller being configured so as to measure electrical signals received from the input electrical conductors so that application of electrical signals to the output electrical conductors and measurement of electrical signals at the input electrical conductors provide sufficient information to derive the optical radiation measurements.

23. The apparatus of claim 22 further comprising a plurality of reference elements having a predetermined and substantially constant electrical resistance, the reference elements being connected with the output electrical conductors and with the input electrical conductors so as to form crosspoint connections.

24. The sensor apparatus of claim 22, wherein each of the sensors has a dark resistance of no more than about 0.5 mega-ohms and a fully illuminated resistance of no less than about 30,000 ohms.

25. The sensor apparatus of claim 22 further comprising a thermistor connected with the controller and configured so as to provide a reference correction factor for temperature.