Z-stage configuration and application thereof
A stage configuration is provided, wherein a ceramic plate is used as the z-stage body to decrease the use of the metal plates in the conventional configuration, so that the compact structure of the z-stage may decrease the vibrational movements of the z-stage. Further, two Laser interferometer are used to detect a movement of different points along a vertical line of the z-stage sidewall to calculate a movement of the specimen surface, so that a horizontal movement of the specimen surface can be detected more accurately.
1. A z-stage configuration, comprising:
a metal plate;
a ceramic plate over said metal plate;
at least three C-shape flex clamps on a peripheral region of said metal plate for supporting said ceramic plate, wherein each clamp has a piezo actuator; and
two mirrors fastened to two sides of said ceramic plate, wherein said two sides are perpendicular.
2. The z-stage configuration according to claim 1 , wherein said ceramic plate has two step structures adjacent to one corner of said ceramic plate, and said two mirrors are fastened to said two step structures.
3. A stage configuration for adjusting specimen height in a SEM machine, comprising:
a metal plate;
a ceramic plate over said metal plate;
four C-shape flex clamps on corners of said metal plate for supporting said ceramic plate, wherein each clamp has a peizo actuator;
an E-chuck configuration on a surface of said ceramic plate for fastening a specimen;
an EM shielding plate with an opening to expose said E-chuck configuration;
a plurality of stands around said ceramic plate for supporting said EM shielding plate; and
two reflective materials on sidewalls of said ceramic plate.
4. The stage configuration according to claim 3 , wherein said metal plate is a Al metal plate.
5. The stage configuration according to claim 3 , wherein said metal plate is square or polygon.
6. The stage configuration according to claim 3 , said specimen is a wafer or a mask.
7. The stage configuration according to claim 3 , wherein said E-chuck configuration is electric circuits embedded on a surface of said ceramic plate.
8. The stage configuration according to claim 3 , wherein said E-chuck configuration is an E-chuck plate.
9. The stage configuration according to claim 3 , wherein said two reflective materials are formed by polishing said ceramic plate and coating a reflective material thereon.
10. The stage configuration according to claim 3 , wherein said ceramic plate has two step structures adjacent to one corner of said ceramic plate.
11. The stage configuration according to claim 10 , wherein said two reflective materials are two mirrors fastened to said two step structures.
12. The stage configuration according to claim 11 , wherein said E-chuck configuration is electric circuits embedded on a surface of said ceramic plate.
13. The stage configuration according to claim 11 , wherein said E-chuck configuration is an E-chuck plate.
14. The stage configuration according claim 3 , further including multiple Laser interferometers for detecting vibration movement of said z-stage.
15. A system for detecting surface movement of a specimen on a z-stage, comprising:
a first Laser interferometer for detecting a first point on a sidewall of said z-stage;
a second Laser interferometer for detecting a second point on said sidewall of said z-stage, wherein said second point and said first point are along a vertical line of said sidewall of said z-stage; and
means for calculating a surface movement of said specimen according to detected movements of said first and second points, and locations of said first and second points as well as said specimen.
16. A system for offsetting SEM vibration, comprising:
a first Laser interferometer for detecting a first point on a sidewall of a z-stage;
a second Laser interferometer for detecting a second point on said sidewall of said z-stage, wherein said second point and said first point are along a vertical line of said sidewall of said z-stage;
first means for calculating a surface movement of a specimen according to detected movements of said first and second points, and locations of said first and second points as well as said specimen;
a third Laser interferometer for detecting a third point on a sidewall of an E-beam column; and
second means for calculating a movement of said E-beam column to offset said surface movement of said specimen.
17. The system according to claim 16 , further comprising a reflective mirror fastened to said E-beam column for said third Laser interferometer detection.
18. The system according to claim 16 , further comprising a reflective mirror fastened to a top cover of a chamber for said third Laser interferometer detection, wherein said E-beam column is mounted to said top cover.
19. A method for offsetting SEM vibration, comprising:
detecting a first point on a sidewall of a z-stage by a first Laser interferometer;
detecting a second point on said sidewall of said z-stage by a second Laser interferometer, wherein said second point and said first point are along a vertical line of said sidewall of said z-stage;
calculating a surface movement of a specimen according to detected movements of said first and second points, and locations of said first and second points as well as said specimen;
detecting a third point on a sidewall of an E-beam column by a third Laser interferometer; and
calculating a movement of said E-beam column to offset said surface movement of said specimen.
20. A system for offsetting an E-beam column movement, comprising:
a Laser interferometer for detecting a point on a sidewall of said E-beam column; and
means for calculating a movement of said E-beam column to offset a surface movement of a specimen to be inspected by said E-beam column.