ASML Stepper 3 Standard Operating Procedure

Regular Procedures for ASML Stepper

Normal User Procedures:

1. Cleaning the back-sides of wafers:  Very important

1. 1. Make sure all work surfaces/spin chucks/hot plates are cleaned!  Don’t use wipes, place baked wafers directly on cleaned steel surfaces.
   2. Cleaning residue of AR2 or DSK101:  This technique is much better than trying to wipe.  Use clean gloves and hold the wafer edges with your hands.  
      1. After spin coating, place wafer upside down in POLOS spinner using non-contact chuck.  
      2. Set spin speed to 2000rpm.  
      3. Spin wafer, wait until at top speed.
      4. Squirt Acetone on sample back for 3 seconds. Followed by ISO for 3 sec.
      5. Spin Dry while blowing with N2.
      6. Remove wafer and do bake as normal
   3. Cleaning residues of UV210, UV6, UNV2300, or PEK-162C1
      1. After baking and cooling, place wafer upside down in POLOS spinner using non-contact chuck.

1. 1. 1. Set spin speed to 2000rpm.  
      2. Spin wafer, wait until at top speed.
      3. Squirt Acetone on sample back for 3 seconds. Followed by ISO for 3 sec.
      4. Spin Dry while blowing with N2.

1. 1. Check back-side of wafer thoroughly for particulates before loading into system!  If you see particulates, try to blow then off with high N2 flow first, you may need to get physical with a razor blade to remove stubborn particles. It is crucial that particles do not get tracking into the system's exposure chuck - sub-µm features will have resolution issues if a particle alters the local wafer focus.

1. Reticle Unloading  and Loading

a.    Material Handler (button near top right of main software window)

1.    Remove reticles from machine

2.    Exchange reticle box

3.    Unlock box3 

b.    Physically Remove desired reticle pod(s), green indicator at box should be lit and all reticles should be up inside box, not down into machine.

c.    Use manual box opener to open reticle box.  Move arm slowly.  

d.    Remove Pod Lid

e.    Remove (or add) reticle to pod.  Two stars on reticle should be in front.

f.     Place Pod lid back on

g.    Close Pod using arm, move arm slowly

h.    Place Pod back in stepper

i.     Read desired pods

j.     Go back to main menu once mask barcodes are all showing on screen

3.    Wafer Load

a.    Open lid, Remove cassette

b.    Place wafers in slots (make sure backs of wafers are extremely clean!  No Particles! No residues!  Be extra careful and attentive to this detail!  See Brian Thibeault for instructions.  

c.    Place cassette back.  Make sure cassette is pulled back snugly in place

d.    Close Lid.

e.      

4.    Running a Job – Normal operation

a.    Batch Control

i.     Task Streaming

1.    Wait until wafers are read by machine

2.    Task: Append Batch (or select a previous batch and copy)

3.    Enter Batch ID first, Hit Return to apply change

4.    Press Select Button under Job Name and navigate to your job

5.    Click on Layer ID to get a list of layers you can expose: Select layer you want

6.    Enter number of wafers in Batch Size

7.    Batch Type is P for production run (see below for doing a FEM)

8.    Verify Energy, Focus Offset, Ilumination Mode, NA, Sigma and change as desired

9.    Hit Action: Apply button to register all changes

10.  Press Accept Button at Top

11.  Press Continue Button to execute batch.

12.  If batch has general failure:  Choose “clear litho cluster” option.

5.    Running a focus and/or exposure matrix

a.    Follow Running a Job procedure until Step 7

i.     Under Batch Type:

1.    Choose E for exposure snake (with flat down, first exposure lower left increments to the right, snakes around entire array).  Enter starting exposure in mJ and incremental exposure in mJ.

2.    Choose F for focus snake (with flat down, first exposure lower left increments to the right, snakes around entire array).  Enter starting focus offset and incremental focus for the snake. 

3.    Choose M for FocusExposureMatrix (FEM).  Center cell 0,0 is the nominal Exposure and Focus value you enter.  The array is incremented up and down from the nominal value. Exposure time varies in columns, Focus in Rows.

b.    Verify non-varied parameters as well as Ilumination Mode, NA, Sigma and change as desired.

c.    Hit Action: Apply button to register all changes

d.    Press Accept Button at Top

e.    Press Continue Button to execute batch.

Error, Calibration, Error logging Procedures for Users:  

1.    If Error Log full:

a.    Close logging window 

b.    Open new window on console (Rt click, select ASML)

c.    At % prompt, type logging (all lowercase!)

d.    Resize window and place in upper right area of screen as normal.

2.    IQC (Image Quality Control)

a.    Test Manager

i.     Run Test

1.    Metrology Verification

2.    Image Quality Control

3.    Accept (Upper Button)

4.    Perform Measurement

5.    Choose System Correction

6.    # Cycles: 1, #Measurements: 3, # Corrections: 1 (UCSB numbers for test 1  3  1  M)

7.    Accept to run the test

ii.     If |focus correction| < 50nm, system OK, note number in log book

iii.     If |focus correction| > 50nm, run test again, if number keeps dropping, keep running until number stable

iv.     If |focus correction|is still > 50nm, discuss with engineer 

3.    Wafer Handler Issues during batch operation

a.    Lift black cover behind keyboard

b.    Press AWH button and release

c.    Wail until wafer handler “system booting” is done and warning window in bottom left of main computer console has disappeared.

d.    Exit to main menu (DO NOT do FAST STARTUP from error message, go to main menu!)

e.    Go to Start/Stop

f.     Fast Startup

g.    Start

h.    Once complete, back to main menu.

i.     If wafers in machine, go to material handler. 

i.     Go to Remove wafers menu and collect wafers

ii.     Back to main menu when finished.

j.     If system says wafer is missing, contact engineer

4.    Laser Refill (or laser calling for gas injection)

a.    Test Manager

b.    Cmd Handler (Top Menu)

i.     Illumination and Projection

ii.     Illumination

iii.     New Laser Fill (Use Laser Start instead if laser asking for gas injection)