Method for testing pixels for LCD TFT displays

• US 20060028230A1
• Filed: 10/29/2004
• Published: 02/09/2006
• Est. Priority Date: 08/03/2004
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Schmid, Ralf, Brunner, Matthias, Wenzel, Axel
• Granted Patent: US 7,256,606 B2
• Time in Patent Office: Days
• US Class Current: 324/754.220
• CPC Class Codes: G01N 23/2251 using incident electron beams, e.g. scanning electron microscopy [SEM]
• CPC Class Codes: G02F 1/136254 Checking; Testing

Abstract

The present invention provides a method of electron beam testing of liquid crystal displays comprising non-uniform electrodes having a conductive portion and a dielectric portion. In accordance with methods of the present invention, the diameter of the electron beam is increased so that the beam is less focused, i.e., enlarged or “blurred,” over a non-uniform electrode area. The diameter of the beam is increased so that the beam generates secondary electrons from the conductive portion of the non-uniform electrode area. The configured test beam may be circular, elliptical, or other suitable shapes.

Claims

1. A method for conducting electron beam testing of TFT devices on a flat panel display substrate comprising non-uniform electrode areas, each non-uniform electrode area having a conductive portion and a dielectric portion, the method comprising:

configuring an electron test beam to have an area that is sufficient to cover at least partially the dielectric portion and at least partially the conductive portion; and

directing the electron test beam onto the non-uniform electrode area.

2. The method of claim 1, wherein the area of the electron beam is at least about 50% of the non-uniform electrode area.

3. The method of claim 1, wherein the area of the electron beam is between about 50% and about 90% of the non-uniform electrode area.

4. The method of claim 1, wherein the configured electron test beam is circular in shape.

5. The method of claim 1, wherein the configured electron test beam is elliptical in shape.

6. A method for conducting electron beam testing of TFT devices on a flat panel display substrate comprising non-uniform electrode areas, each non-uniform electrode area having dielectric lines formed over a conductive portion, the method comprising:

configuring an electron test beam to have a diameter that is sufficient to cover at least partially one of the dielectric lines and to cover at least partially a conductive portion; and

directing the electron test beam onto the non-uniform electrode areas of the flat panel display substrate.

7. The method of claim 6, wherein the diameter of the electron beam is between about two times and about ten times a width of one of the dielectric lines.

8. The method of claim 6, wherein the diameter of the electron beam is between about four times and about eight times a width of one of the dielectric lines.

9. The method of claim 6, wherein the configured electron test beam is circular in shape.

10. The method of claim 6, wherein the configured electron test beam is elliptical in shape and the diameter of the configured electron test beam is measured across a minor axis.

11. The method of claim 6, wherein the flat panel display substrate comprises a multi-domain vertical alignment (MVA) display substrate.

12. A method for conducting electron beam testing of TFT devices on a flat panel display substrate comprising non-uniform electrodes areas, each non-uniform electrode area comprising a first electrode and a second electrode separated by a dielectric portion, the method comprising:

configuring an electron test beam to have a diameter that is sufficient to cover at least partially the first electrode, at least partially the second electrode, and at least partially the dielectric portion; and

directing the electron test beam onto the non-uniform electrode areas of the flat panel display substrate.

13. The method of claim 12, wherein the diameter of the electron beam is between about two times and about ten times a width of one of the dielectric lines.

14. The method of claim 12, wherein the diameter of the electron beam is between about four times and about eight times a width of one of the dielectric lines.

15. The method of claim 12, wherein the configured electron test beam is circular in shape.

16. The method of claim 12, wherein the configured electron test beam is elliptical in shape and the diameter of the configured electron test beam is measured across a minor axis.

17. The method of claim 12, wherein the flat panel display substrate comprises a in plane switching display substrate.

18. A method for conducting electron beam testing of TFT devices on a flat panel display comprising non-uniform electrode areas, each non-uniform electrode having a dielectric portion and a conductive portion, the method comprising:

configuring an electron test beam to have a first area that is about 20% or less than the non-uniform electrode area;

directing the electron test beam over a positioning mark on the substrate to align a position of the electron beam;

re-configuring the electron test beam to have a second area greater than 20% of the non-uniform electrode area; and

directing the electron test beam sequentially over the non-uniform electrode areas.

19. The method of claim 18, wherein the configured electron test beam is circular in shape.

20. The method of claim 18, wherein the configured electron test beam is elliptical in shape and the diameter of the configured electron test beam is measured across a minor axis.

21. The method of claim 18, wherein the second area of the re-configured electron test beam is between about 50% and about 90% of the non-uniform electrode area.