Method and apparatus for wafer marking
View Patent ↗A semiconductor substrate is provided. The substrate includes a first surface and an opposing second surface, wherein the first surface includes a marking in a centroid region of the first surface. The marking indicates a location of a center point on the first surface of the semiconductor substrate or identification data unique to the substrate. A system, methods of transporting and marking, and a device for reading the substrate markings are also provided.
1. A substrate transport system, comprising:
a substrate having a marking located within a central region of a surface of the substrate, the marking identifying a center point of the substrate, wherein the marking includes one or more first fiducial element indicating a center point, and one or more second fiducial element indicating an angular orientation of the substrate;
a transport mechanism for transporting the substrate over a transport path;
a sensing element configured to capture the marking from the surface of the substrate; and
a computing device configured to process the captured marking to identify the center point.
2. The system of claim 1 , wherein the marking identifies one of an angular orientation of the substrate or a unique identifier of the substrate.
3. The system of claim 2 , wherein the angular orientation indicates a crystallographic orientation.
4. The system of claim 1 , wherein the computing device and the sensing element are integrated into a single unit.
5. A semiconductor substrate, comprising;
a first surface and an opposing second surface, wherein the first surface includes a marking in a centroid region of the first surface, the marking indicating one of a location of a center point on the first surface of the semiconductor substrate or identification data unique to the substrate; and a second marking in the centroid region indicating an angular orientation of the semiconductor substrate.
6. The semiconductor substrate of claim 5 , wherein the second marking indicates the angular orientation with respect to the crystallographic orientation of the semiconductor material.
7. The semiconductor substrate of claim 5 wherein the marking indicates an angular orientation of the semiconductor substrate and wherein the marking is disposed within a recess defined on the first surface.
8. The semiconductor substrate of claim 5 , wherein the marking includes two parallel lines on opposing sides of a centerline of the semiconductor substrate, the centerline within a plane of the semiconductor substrate.
9. A device configured to read semiconductor substrate markings, comprising:
a sensor located within a support member and positioned to capture the markings on a center region of a surface of a semiconductor substrate, wherein the markings provide a unique identifier of the semiconductor substrate, wherein the support member is an end effector and the sensor is located within a recess of a surface of the support member.
10. The device of claim 9 , wherein the sensor includes an image capture device configured to capture images of the surface of the semiconductor substrate, and wherein the sensor is in communication with a computing device having image recognition logic configured to process the captured images to determine one of a location of a center point of the substrate or an angular orientation of the substrate.
11. The device of claim 10 , wherein the sensor includes a light source configured to illuminate the surface of the semiconductor substrate.
12. The device of claim 11 , wherein a diffuser is disposed over the light source.
13. The device of claim 9 , wherein the sensor is positioned to scan across a top surface of the substrate to access markings on a bottom surface of the substrate.
14. The device of claim 9 , wherein the sensor is located within a recess on a surface of a semiconductor substrate support and wherein the semiconductor substrate support is one of a process chuck, a metrology chuck or a process tool chuck.
15. The device of claim 14 , wherein the semiconductor substrate support is rotatable.
16. The device of claim 14 , wherein the semiconductor substrate support is disposed within an aligner for a semiconductor processing tool.
17. The device of claim 9 , wherein the markings include a single fiducial for identifying the center point and a pair of fiducials for identifying an angular orientation.
18. The device of claim 9 , wherein the sensor includes an image capture device.
19. A method for transporting a substrate, comprising:
obtaining the substrate from a substrate container;
transporting the substrate from the substrate container wherein a center region of a surface of the substrate passes over a sensor, the transporting including,
reading position indicating markings on the center region of the surface of the substrate, wherein the reading of the position indicating markings is performed without rotation of the substrate and wherein a drop off position to the processing tool is adjusted based on the identified center point; and
identifying a center point of the substrate from the position indicating markings.
20. The method of claim 19 , wherein the position indicating markings include first and second sets of fiducials, the first set including a single fiducial indicating a center point of the substrate and the second set including a pair of fiducials indicating an angular orientation of the substrate and wherein a drop off position to the processing tool is adjusted based on the identified center point.
21. The method of claim 19 , further comprising:
reading unique identifiers on the center region of the surface of the substrate; and
adjusting a drop off position to the processing tool based on the identified center point.
22. The method of claim 19 , wherein the reading is performed through an opposing surface to the surface having the position indicating markings.
23. A method for marking a semiconductor substrate, comprising:
identifying one of a center point of the substrate or a crystallographic plane of the substrate; and
generating a marking indicating a location of one of the center point, an angular orientation relative to the crystallographic plane or a unique identifier, the marking located in a center region of a surface of the semiconductor substrate, wherein the generating includes creating a recess in the center region, and imprinting the marking in the recess.
24. The method of claim 23 , wherein identifying the crystallographic plane includes receiving x ray, electron beam or optical energy from the surface of the semiconductor substrate.
25. The method of claim 23 , further comprising:
defining a notch on an outer periphery of the substrate, the notch correlated to the crystallographic plane.
26. The method of claim 23 , wherein identifying the crystallographic plane of the substrate includes reading a notch on a periphery of the substrate.