Differences

This shows you the differences between two versions of the page.

--- electron_beam_lithography [2008/05/29 16:15] – verstoep
+++ electron_beam_lithography [2008/06/03 10:54] (current) – verstoep
@@ Line 76: / Line 76: @@
   - Load the sample into the SEM by using the loadlock which is controlled by the red button. With this single button you can vent and pump down the loadlock. The button lights up if the loadlock is venting or pumping down. Read the [[JEOL 820 SEM#Startup|Start-Up Section of the JEOL 820 SEM Wiki]] for a step-by-step description of the load-process.
   - Slide the sample holder inside the vacuum chamber onto the stage.
 ===== System Start-Up =====
   - Turn on the display of the computer. Log in to Elphy Quantum.
-  - Set the working distance of the SEM to 10 mm. (OR: 8 for exceptional situations, 3x3 or 4x4 marker for large fields)
+  - Set the working distance of the SEM to 10 mm (8 in exceptional situations) for small structures, 3x3 for a 3x3 mm working field or 4x4 marker for a 4x4 mm working field
   - check that aperture (Diafragma) '3' is selected (At the extruding part at the top of the SEM).
   - Drive the stage to the chessy position with the ''stage control'' window. This is done so that you will not accidentally expose the resist when moving the stage later on. In general: **don't image your sample, because it will expose your resist!**.
+  - Check that PCD is on.
   - Check that the voltage is set to 20 kV and that the filament current is 0 A.
   - Turn on the main power (red square button). It will light up.
@@ Line 99: / Line 102: @@
     - Set the current to about 1 nA (With bottom right knobs)
   - Improving the image
-    - Use the knobs on the bottom console to change brightness and contrast. The option coarse allows you to toggle between making large or small adjustments.
+    - Use the knobs on the bottom console to change brightness and contrast.
     - Use magnification and the position joystick to change the position you look at.
-    - Focus the image (you should be able to have a 100 nm resolution)
+    - Focus the image (you should be able to have a 100 nm resolution). The option coarse allows you to toggle between making large or small adjustments.
     - Change the current with the bottom right knobs ''course'' and ''fine''. You should see the measured current on the sample change.
     - iterate the above steps.
@@ Line 110: / Line 113: @@
 ====== Calibration ======
 ===== Calibrate the Write field on the chessy =====
@@ Line 118: / Line 122: @@
   - Go to desktop 3
-  - Set Magnification to desired value (for example 100X)
-  - Drive the stage to the center of a chessy block (point at it and click ''<crtl+mouse-right>''. repeat if necessary
   - Set the hardware to: slow 2 / EBPG / Beam Blanking external
-  - Select your writing field (you can use 400 (@ 50X ?) um OR 800 um (@ 100X)) in microscope control and click ''set''
+  - Select your writing field in microscope control and click ''set''. A magnification of 20X gives you a writing field of 3000 um; 100X = 800 um; 170X = 400 um; etc. For magnifications 100X and higher the best lens is used.
+  - Set Magnification with the knob to the corresponding value you have entered for the writing field.
   - Open a new image (file->new image) and scan it (Press the icon with (a microscope-ray?) and a small 1 in the bottom-left corner).
   - The image should have the right size and not be rotated (it doesn't have to be centered); If not: follow the steps below (normally not necessary unless something weird happens like the JEOL service people recalibrating the scan field of the SEM itself :-) ).
   - **Course:**
-    - Drive the stage to the center of a chessy block (point at it and click ''<crtl+mouse-right>''. repeat if necessary
+    - Drive the stage to the center of a chessy block (point at it and click ''<crtl+rightmouse>''. repeat if necessary
-    - Open a writefield calibration positionlist (file->open position list) called ''Align<size>'' or ''align<size>''
+    - Open a writefield calibration positionlist (file->open positionlist) called ''Align<size>'' or ''align<size>''
     - Scan the image. Maximize the window of the image.
     - Markers appear in the image
     - Drag (ctrl-leftclick) all 4 markers to the right place. They have to be moved!
-    - To apply the alignment press ''calculate'' and ''send''
+    - To apply the alignment press ''calculate'' and ''send'' in the ''align write field''-window.
   - **Fine:**
     - Optionally scan the image again.
@@ Line 139: / Line 143: @@
     - Iterate the above steps if necessary.
     - Close the image window (Don't save), Close the postionlist (Don't save)
-    - Set ''shift'' to zero
+    - Set ''shift'' to zero by subtracting the current values.
-    - Press send (Where?)
+    - Press send in the ''align write field''-window.
 ===== UV coordinate system calibration =====
@@ Line 175: / Line 179: @@
 ====== Writing ======
 ===== Preparing your program =====
@@ Line 181: / Line 186: @@
   - Load the positionlist you want to write: file->open position list
   - Make sure your Area Dose corresponds to your process (For hardening resist, you typically require between 40 and 160 uAs/cm<sup>2</sup>). You can check this by [right-clicking] on an entry in your position list; select [properties]. Expand dialog by pressing [exposure parameters]. Press [calculator].
-  - Make sure you have selected the right layer for exposure. Check by?
+  - Make sure you have selected the right layer for exposure. This is indicated with an integer in the layer field of your list.
+  - In the positionlist your Pos1 & Pos2 should be half the size of your writing field.
 There are two ways to do the etching: with beam stabilizer OR without beam stabilizer.