Alignment Assembly

• US 20090067976A1
• Filed: 09/12/2007
• Published: 03/12/2009
• Est. Priority Date: 09/12/2007
• Status: Active Grant

• Current Assignee: Carl Zeiss X-ray Microscopy, Inc. (Carl-Zeiss-Stiftung)
• Original Assignee: Xradia, Inc. (Carl-Zeiss-Stiftung)
• Inventors: Xu, Ying
• Granted Patent: US 8,267,388 B2
• Time in Patent Office: Days
• US Class Current: 414/757
• CPC Class Codes: H01L 21/68 for positioning, orientation or alignment
• CPC Class Codes: Y10T 83/7697 Tool angularly adjustable relative to work-support
• CPC Class Codes: Y10T 83/773 Work-support includes passageway for tool [e.g., slotted table]

Abstract

Alignment assembly is used to center a sample on a moving stage system. The alignment assembly includes a pair of slides stacked on a stage with linear perpendicular movement relative to each other, and at least one actuator that is preferably physically separate from the linear slides and stage. The actuator(s) repeatedly extend an actuator arm to move the linear slides, and retract the arm for subsequent movement of the stage during and after the process of centering the sample in two dimensions on the stage. Either the stage system rotates, or multiple actuators are placed to move the alignment system in perpendicular directions relative to the stage, by repeatedly contacting only the top linear slide.

Claims

1. An alignment assembly comprising:

a rotation stage;

a bottom linear slide on top of the rotation stage that is limited to move in a first direction relative to the rotation stage;

a top linear slide on top of the bottom linear slide which is limited to move in a second direction that is perpendicular to the first direction;

a sample holder residing on top of the top linear slide, for holding a sample;

at least one actuator assembly that moves the bottom linear slide and the top linear slide to align the sample.

2. An alignment assembly as in claim 1, further comprising a measurement device that is physically separate from the rotation stage for measuring a position of the sample to control movement of the top linear slide and the bottom linear slide by the at least one actuator assembly.

3. An alignment assembly as in claim 1, wherein the at least one actuator assembly comprises at least one extending arm that engages at least the top linear slide.

4. An alignment assembly as in claim 3, wherein the actuator arm of at least one actuator assembly pushes on the top linear slide to align the sample.

5. An alignment assembly as in claim 1, further comprising a motor for turning the rotation stage.

6. An alignment assembly as in claim 1 wherein the top linear slide and bottom linear slide are magnetically loaded against each other to maintain their relative positions.

7. An alignment assembly as in claim 1 wherein at least one actuator arm of at least one actuator assembly selectively moves either the top linear slide relative to the bottom linear slide or the top linear slide and the bottom linear slide relative to the rotation stage by rotating the rotation to align axes of movement of the top linear slide and the bottom linear slide to an axis of movement of the at least one actuator arm.

8. An alignment assembly as in claim 1 wherein an actuator arm of the at least one actuator assembly pushes the top linear slide and/or the bottom linear slide away from the actuator assembly.

9. An alignment assembly as in claim 1 wherein an actuator arm of the at least one actuator assembly is selectively electro-magnetized to both push and pull the linear slides.

10. An alignment assembly as in claim 1 wherein a top surfaces of the rotation stage and the bottom linear slide each have two parallel grooves, and the bottom surfaces of the top linear slide and bottom linear slide each have three raised contacts that engage the parallel grooves.

11. An alignment assembly as in claim 10 wherein one of the two parallel grooves is a V groove and the other is a flat groove.

12. An alignment assembly as in claim 10 wherein the raised contacts are spherical.

13. An alignment assembly as in claim 10 wherein the raised contacts are constructed out of a separate substance.

14. A rotary stage assembly comprising;

a reference frame;

a rotation stage that rotations on the reference frame;

a motor for driving the rotation stage;

an alignment assembly on the rotation stage, the alignment assembly comprising two stacked linear slides;

a sample holder for holding a sample on the alignment assembly;

a set of actuators placed to move the rotation stage relative to the reference frame to control an axis of rotation of the rotation stage;

a set of sensors placed to measure the rotation stage relative to the reference frame to detect changes in the axis of rotation;

wherein the alignment assembly is used to center a region of interest of the sample relative to the axis of rotation of the rotation stage, and the actuators and sensors are used to correct a placement of the axis of rotation.

15. A method for aligning a sample on an alignment assembly that resides on a rotation stage, to an axis of rotation of the rotation stage, using an actuator to move the alignment assembly, comprising two orthogonal linear slides, and an external measurement device to measure a location of the sample, the method comprising the steps of:

(a) rotating the rotation stage until a direction of movement of the alignment assembly is parallel to the movement of the alignment arm,

(b) measuring the location of the sample,

(c) successively rotating the rotation stage 90 degrees until the sample is a closest to the actuator assembly as possible,

(d) pushing the at least one of the linear slides with the actuator arm until the sample is the same distance from the actuator assembly as the center of rotation,

(e) repeating steps (c) and (d).

16. An alignment assembly comprising:

a stage;

a bottom linear slide on top of the stage that is limited to move in a first direction relative to the stage;

a top linear slide on top of the bottom linear slide which is limited to move in a second direction that is perpendicular to the first direction;

a sample holder residing on top of the top linear slide, for holding a sample;

at least one actuator assembly that moves the bottom linear slide and the top linear slide to align the sample.