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SVG Coat Tracks, svgcoat/svgcoat2 new

The SVG (Silicon Valley Group) coater is an automated track system for dispensing photoresist on 4" silicon, glass, or quartz wafers. The system includes two stations: a prime oven which bakes the wafer and dispenses the adhesion promoter, HMDS; and a combination spinner, which dispenses photoresist, and pre-bake oven which cures the resist. HMDS is only available at track 2. The uniformity of spun photoresists are typically +/- 100 Å. Features: * Two automated, single-wafer track systems. * Dispenses any of four different positive photoresists. * Selectable programs at the spinner and each of the bake ovens. * "Manual" dispense program allows the user to dispense other approved photoresists, on track 1 only

Picture and Location

 SVG Coat Tracks

This tool is located at D3 on the Lab Map.

 

Process Capabilities

Cleanliness Standard

 The svgcoat appears in "All" three equipment groups (clean, semiclean, and gold).

 

How to Become a User

 

  1. "All Litho" is required before training on any of the lithography tools. Contact the trainers for the class schedule and training materials (which must be reviewed before the class).
  2. Read all material on the SNF website concerning this tool, including Background, Process Capabilities, Operating Procedures and Process Monitoring.
  3.  View the SVG coater training movie, you will find the link on the training video page.
  4. Print the SNF Shadowing Form and the SVG checklist on clean room paper and contact a qualified user of the wet bench to arrange to ‘shadow’ them while they use the tool. You are responsible to be with that labmember for the full time they are operating the tool, and it would be intelligent to ask questions and try to become as familiar as possible with the wet bench during this ‘shadowing.’  You may have to shadow the qualified user more than one time. The qualified user and you will have to sign the SNF Shadowing Form.
  5.  Contact SNF training contact on the Equipment Summary page.
  6. For training please see the Training Calendar for scheduled trainings.

Operating Procedures

 

Overview:

Track 1:

  • Resist Coat
    • Shipley 3612 for std 1 µm or 1.6 µm resist
    • SPR220-7 for std 7 µm, or 10 µm resist or thicker films
    • SPR220-3 for std 3 µm or 4 µm resist
    • Ebeam Resist - manual application, only PMMA 2%, PMMA 5%, UVN30

Track 2:

  • HMDS vapor prime
  • Resist Coat
    • Shipley 3612 for std 1 µm or 1.6 µm resist
    • SPR 955 CM-.7 I Line resist  for std 0.7 µm,  0.9 µm to 1 µm resist
    • Shipley 3617m for glass or quartz wafers

 


Special Notes or Restrictions:

  • 4 inch round wafers, like silicon, glass, or quartz only, no pieces
  • ASML users: track 2 (back track) is recommended
  • NO manual resist dispense on track 2
  • NO temperature change of the bake stations
  • NO polyimides, NO LOL2000, NO PMMA 950K 9%, NO ZEP, NO SU8 (use the headway coater)
  • Please check the reservation page, users are not allowed to make reservations but staff reserves the tool for training and classes 
  • Check the MSDS sheets for hazard information on the photoresist you are using and handle them with caution.
  • Close the plastic doors to prevent fumes from getting in the lab
  • Notify the staff immediately if resist smells are detected while working at the station.

Operating Procedures:

Check reservation page, staff reserves the tool for training classes.

Enable "svgcoat" for front track or "svgcoat2" for back track.

Before Coating:

  • Check the photoresist waste container under tracks
    • If waste container is half full, press Track 1 or Track 2 (Chemical Delivery Unit, upper right corner) to pump the waste into the large waste container (system drain) inside of the flammable cabinet.
    • If waste container alarm goes on, the track will shut down. Silence alarm, empty waste container, switch alarm back on, continue working.
    • If large waste container (system drain) alarm goes on: Silence alarm, shut system down on Coral and contact maintenance.
  • Flammable cabinet behind the tool:
    Check the amount of resist in the bottle you are going to use and change resist bottle if there is only one inch left in the bottle.
  • Check the temperature of the hotplates
    • Track 2 only: Prime set at 125°C (DO NOT change the temperature)
    • Bake set at 90°C (DO NOT change the temperature)
  • Select programs
      Use the "recipe manager" program. Instructions are next to the tool.
    • Check "Rules for Operating svgcoat/svgcoat2"  page next to the tool for complete list of prime, coat, and bake programs.

Check that all stations are in Auto Mode. The LED next to the word Auto should be on.

Place wafers in metal cassette and put cassette on the load station (left side).

  • It is recommended to run three or more dummy wafers prior to your process wafers. You will find dummy wafers in a box next to the SVG coater. The dummy wafers might have some resist on the front side. If you re-use a dummy wafer, make sure the back side has NO resist!
    Place the first wafer at the bottom of the cassette, front side facing up!
  • Watch out for the plastic stopper at the metal cassette!

Place an empty metal cassette onto the unload station (right side).

  • If a cassette is already present, tilt it for reset, otherwise the machine does not know there is a new cassette and will not transfer wafers from the cool plate to the cassette.
  • NEVER PUT WAFERS RESIST SIDE DOWN on a hotplate.
  • Either coat them in manual mode using only the coater station OR select a program number on the singe and bake stations that has the first event "END". This will bypass these stations in AUTO mode.

Press "START"

Don't leave the system while your wafers are running.

Problems: ALARM SOUNDS on track

    FIX.... Press "CLEAR" in the "recipe manager" program, then locate the problem and correct it.

      • Possible Reason: Look for belts turning.
        • If belts are turning, someone has removed a wafer before completion of process. Take a dummy wafer and place it on the turning belts, remove and resume your run.
      • Possible Reason: Spinner chuck does not turn.
        • Look for red lights on the controller, push them to clear red light

Problems: UTILITY ALARM panel upper left corner:

if alarm sounds: switch Audible Alarm "OFF", locate problem and correct it, switch Audible Alarm back to "ON"

  • track 1 resist 1: Shipley 227-7 bottle is empty
  • track 1 resist 2: Shipley 3612 bottle is empty
  • track 1 resist 3: Shipley220-3 bottle is empty
  • track 2 resist 1: Shipley 3612 bottle is empty
  • track 2 resist 2: Shipley3617 bottle is empty
  • track 2 resist 3: Shipley955 bottle is empty
  • System Drain: main resist waste container is full, shutdown system and contact maintenance
  • Track 1 Drain: track 1 resist waste container is full, press Track 1 on Chemical Delivery Unit, upper right corner
  • Track 2 Drain: track 2 resist waste container is full, press Track 2 on Chemical Delivery Unit, upper right corner
  • Track 1 EBR: EBR at track 1 is empty, shutdown track 1 and contact maintenance
  • Track 2 EBR: EBR at track 2is empty, shutdown track 2 and contact maintenance
  • Track 2 HMDS: HMDS at track 2 is empty, shutdown track 2 and contact maintenance
  • how to exchange resist bottle:
    find appropriate resist bottle in flammable cabinet, use only a new bottle if available, if you can't find a bottle: contact stock room. Transfer chemicals only in metal cart, never hand-carry chemicals. Exchange bottles, return used bottle to flammable cabinet. To remove air bubbles
    in the resist lines run three or more dummy wafers.

    Once all wafers are in the receiving cassette, press "Reset Receiver Station" in the ‘recipe manager’ program, the cassette will move up.
    Remove the cassette from the station, place the dummy wafers back into the dummy wafer box and your wafers in your transportation box. Clean up!

    Disable "svgcoat" or "svgcoat2".

     

    Process Monitoring and Machine Qualification

    Process Monitoring

    There are 2 places to find process monitoring of the svgcoat tracks: Litho Qualification runs done by staff and thickness results saved in Coral.

     

    The results of Litho Qualification runs can be found in spreadsheets here:

    https://snf.stanford.edu/SNF/processes/process-modules/photolithography/photolithography-qualifications-1

     

    Thickness results saved in Coral can be plotted following the 4 steps shown via images below.

    First, select the coat track you are interested in, then select Process Actions > Display run data.

    LQ_1_makenew

     

    Second, use the drop-down menu to select "Qualification."

    LQ_2_selectquals

     

    Third, select the resist type you are interested in in the first of 3 new dropdown menus. Change the range of dates you are interested in. Note that the autoscaling of the axes may make it preferable to select a range of months instead of weeks so that the graph is not zoomed-in so much that it is hard to interpret. Fourth, click "Display."

    LQ_3_display

     

     

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