EBL Auto Alignment Protocol

EBL Auto Alignment Protocol

EBL auto alignment protocol

 

Outline

  1. Mark Position Measurement
  2. Mark Detection
  • Auto Alignment

 

Section I. Mark Position Measurement

  1. Place cassette upside-down, onto the circular Teflon platform located on the manual alignment fixture
  2. Remove the backing plate of the exposure aperture (A, B, C or D) by rotating the locking tab and aligning the keyway to facilitate the backing plate removal
  3. Place the sample into the exposure aperture with the PMMA coated side, facing DOWN
  4. Secure the backing plate onto the exposure aperture. Place the cassette on the microscope as shown in the image below
  5.  
  6. Turn the alignment stage power on
  7. Position the plate (face down), align the plate edge to build-in guiders and lock the plate
  8. Move the camera right underneath the aperture to be used
  9. Do theta adjustment. Focus on the sample, turn the backing plate of the aperture to adjust the theta
  10. Once theta adjustment is done, move the stage to align the longitude edge of the window with the microscope cross. Press the “//CE” button to activate the position meter. Move to the opposite longitude edge and record the position X
  11. Use the same technique to find Y. The center of the window should be at (X/2, Y/2)
  12. Move stage to (X/2, Y/2). Press “//CE” button again to zero the readings
  13. Move the microscope cross to the position of PQRS, record the coordinates, ignore the dot
  14. Blow off the entire cassette with dry Nitrogen Gas. A nitrogen gun is located in the rear of the laboratory

 

Section II. Mark Detection

  1. L-clk STGCOM
  2. L-clk EDIT PARAMETER
  3. L-clk SELECT (Opens Selection Menu)
  4. L-clk %2A, %2B, %2C, or %2D (highlight the sample location: Multi-piece cassette)
  5. L-clk APPLY
  6. L-clk CANCEL (Closes Selection Menu)
  7. L-clk MOVE (will move the stage to the CENTER of the APERTURE opening)
  8. Select RELATIVE POSITION* (For movement option)
  9. Enter the X (inverted) and Y coordinates of one alignment mark (The coordinated recorded in step #12 in Section I) Note: Only the X coordinate is inverted.
  10. L-clk MOVE (will move stage to the ALIGNMENT mark – P, Q, R or S)
  11. Select lens 4 on the console (This gives broader field of view).
  12. Press MAG button. Press DOWN ARROW to minimize magnification
  13. Press SEI button. Now the mark should appear on the screen. (Note: the line could be very thin with low current, e.g. I= 100pA. In this case, press UP ARROW to zoom in for better view)
  14. Move the stage to center the alignment mark to the center of display. Write down the coordinates of the mark (X4, Y4)
  15. Press CLR button to disable SEI. Switch to Lens 5
  16. Move the stage to (X5’,Y5’), where X5=X4+70 µm, Y5=Y4-50 µm. This set of coordinates gives the rough position of the mark under Lens 5.
  17. Press SEI. Center the mark to the center of the display. Write down the accurate coordinates under Lens 5 (X5, Y5)
  18. Deselect Rapid Scan. Set SPD to 55. Press SEI, ADD, MD, BLK buttons successively. Now mark detection signals should be displayed on the screen
  19. Press SEI, ADD, MD, BLK buttons successively. Now mark detection signals should be displayed on the screen
  20. Adjust the MAG to separate the peaks, and then GAIN button to increase the size of the peaks. In case of uneven peaks, use the X-ATTEN knob to even them out as best as possible
  21. Write down the GAIN and X-ATTEN values

 

Section III. Auto Alignment

  1. Calculate Theory Coordinates (XT, YT) of the mark. XT=XC+XD, YT=YC+YD, where is XC, YC are the coordinates of window center, XD, YD are the coordinates of the mark in CAD file.
  2. Calculate the Shift Amount: ΔX1=X5-XT, ΔY1=YT-Y5. (X5, Y5) are from step #17 in Section II.
  3. In SETWFR, select P mark detection and change both rough and fine scanning parameters. Input the GAIN and X-ATTEN values. Input calculated Shift Amount (ΔX1, ΔY1) into Material Offset.
  4. Click SAVE and RUN. Markers will be scanned and a shift amount will be displayed in the CALIBRATION window. This is the Modified Shift Amount (ΔX2, ΔY2).
  5. Change Material Offset to (ΔX2, ΔY2). Select PQRS marks and change rough/fine scan parameters for QRS marks. Click SAVE and RUN. Markers will be scanned and a shift amount will be displayed in the CALIBRATION window. This is the Final Shift Amount (ΔX3, ΔY3).
  6. Change the material offset to the final shift amount in SETWFR.
  7. In SDF file, change the window to the one with sample loaded. Change OFFSET to the final offset.
  8. In JDF file, change markers parameters are the same as designed. Make sure the dose is correct.
  9. Compile new MGN file.
  10. Do Array Check and expose the pattern.