Wisconsin Center for Applied Microelectronics

1550 Engineering DrivePhone: 608/262-6877

Madison, WI 53706

Rev. 12/02/15

Cooke Annealer procedure- 1 - 12/02/15

OPERATING PROCEDURE

Cooke Vacuum Annealer

Safety:

1) Impact resistant eye protection required

2) Read SDS for tool process chemicals

3) Training and tool access required

4) Know lab evacuation procedures

5) Know location and use of eye/body showers

Cooke Annealer procedure- 1 - 12/02/15

Material Restrictions:

All materials in/on your sample must be on the “allowed materials list” for this tool before using it. NO EXCEPTIONS. It is the user’s responsibility to make sure that the material(s) they are putting in a tool is on the allowed materials list for that tool. Here is how to check the Allowed Materials list for WCAM tools:

1. Go to WCAM’s website at:

2. Click on the “Chemicals in the Lab” link.

3. Click on the link at the top of the page “LIST OF APPROVED MATERIALS”.

4. Scroll thru the document to find the tool you want to check the materials list for or hit Ctrl + F to bring up a search bar for the document and type in the tool’s name that you want to check the materials list for.

5. If the material(s) that you want to use in a tool are not on the approved list for that tool you may not put your sample in the tool. If you have no other way to process your sample and think it makes sense to use a particular material in a tool you may request that it be added to that tool’s material list by filling out the form on the “Chemicals in the Lab” webpage listed as “New Material Request Form”. Then email your material request form along with a SDS for the material to the WCAM lab manager. The request will be reviewed by the WCAM advisory committee and you will get an email back from the lab manager approving or denying your material request for a particular tool.

Tool Purpose & Restrictions:

The Cooke Anneal System is a vacuum chamber with a hot plate in it for the curing of polyimides and other allowed polymers. The aluminum hotplate inside the annealer is 6 inches (152.4 mm) in diameter. The system has a nitrogen leak valve to create an inert environment inside the vacuum chamber. It reaches a base pressure of about 50mTorr. Maximum ramp up rate for temperature is 12C/minute. The system cools slowly at roughly 1.5C/min. The maximum temperature allowed in the system is 400C.

Tool Safety:

  1. This tool has an interlock controlled by the CRESS system. This is to restrict use of the tool to only users that have gone thru the training process for the tool and have access to it. The CRESS interlock for this tool is the switch to the cooling water, which if not on will not allow the hot plate to heat up.
  2. Do not remove your samples until the temperature displayed on the hot plate controller is below 50C. Do not burn yourself.
  3. When pumping down the chamber the vacuum seal is a pinch point.

User Responsibilities:

  1. Making sure what you put into the tool is allowed to be in the tool.
  2. Do not touch or disturb the thermocouple wires in the vacuum chamber or the Al foil covering the connections to the hotplate.
  3. Filling out the log book in its entirety is required for each use of the tool.
  4. Clean up the area after you are done using the tool.

Operating Procedure:

Control Panel

Procedure for Operating the Vacuum Annealer

The procedure below describes how to operate the vacuum annealer. In addition, it describes how to load samples into the annealer, run a heat profile, remove the samples, and safely place the system in stand-by mode. Curing profiles are stored in memory to be used at any given time. Consult the table of recipes at the end of this document in the appendix.

Note: The vent valve and the mechanical pump switches should never be on at the same time.

Initial System Checks

  • The water interlock (cooling water lines) LED should be onafter you have logged into CRESS and turn on the control power.
  • The mechanical pump switch should be off.
  • The vent valve switch should be off.
  • The process gas valve (nitrogen valve) should be rotated fully clockwise so that it is in the off position.
  • The SP temperature on the hotplate controller should be near room temperature (20 C), once the tool is turned on.

Loading Samples into the Chamber

  • Turn on the control power switch.
  • Turn on the vent valve switch. The chamber should be at atmosphere but if it not wait until you hear that it is vented by listening for the nitrogen to start seeping out of the chamber lid.
  • Slowly lift-up the chamber lid.
  • Turn off the vent valve.
  • If needed, wipe the inside surface of the vacuum chamber using cleanroom wipes soaked with isopropanol (IPA). Wipe the inside of the chamber lid, O-ring, hotplate, and around the inside of the chamber. Do not disturb the piece of aluminum foil or wire connections.
  • Carefully, load the samples(s) into the glass Petri dish on the hotplate. Use the glass petri dish to prevent your device from sliding off the hot plate and from getting the hot plate dirty.
  • Close the chamber lid carefully.
  • Turn on the mechanical pump. Allow the chamber to reach a vacuum pressure below 1 Torr before proceeding.
  • Slowly rotate the process gasvalve counter-clockwise to add nitrogen to the chamber. Increase the gas flow until a pressure of 2.0 – 5.0 Torr has been reached.
  • Selecting and starting the temperature profile:
  • Press Menu.
  • Select Profiles (there are two ways of doing this)
  • Press ‘3’ or,
  • Scroll down and press Enter
  • Select Assign L1 (there are two ways of doing this)
  • Press ‘2’ or,
  • Scroll down and press Enter
  • It will ask you to now select a profile. The default profile (‘0’) should be shown.
  • Press Enter.
  • Type in the profile number.
  • Press Enter.
  • Press the Menu button three times to reach the main window.
  • Press the S/S to start (or stop) the profile.

At this point, the temperature profile has begun. The temperature controller should say that the process is on. Also, the SP should read the first ramp temperature. The big number on the top of the temperature controller shows the current/actual temperature of the hotplate. The user may now leave and return at the end of processing. Please do not leave your sample in the system for long durations. Remove your sample(s) in a timely manner to allow other users to use the Cooke Anneal System.

Unloading Samples and Shutdown

  • Initial checks:
  • Check to see that the hotplate temperature is near room temperature ( 20C). The temperature should be below 50C before removing samples.
  • Turn off the process gas. Rotate the dial clockwise all the way to stop the nitrogen gas flow. Do not tighten the dial with extreme force.
  • Removing the sample(s):
  • Turn off the mechanical pump.
  • Turn on the vent valve. Vent the chamber until pressure reaches atmosphere (approximately 760Torr).
  • Slowly lift-up the chamber lid.
  • Turn off the vent valve.
  • Remove the sample(s) from the chamber.
  • If needed, wipe the inside surface of the vacuum chamber using cleanroom wipes soaked with isopropanol (IPA). Wipe the inside of the chamber lid, O-ring, hotplate, and around the inside of the chamber. Do not disturb the piece of aluminum foil or wire connections.
  • Clean the glass petri dish and replace.
  • Close the chamber lid carefully.
  • Setting the profile assignment to ‘0’:
  • Press Menu.
  • Select Profiles (there are two ways of doing this)
  • Press ‘3’ or,
  • Scroll down and press Enter
  • Select Assign L1 (there are two ways of doing this)
  • Press ‘2’ or,
  • Scroll down and press Enter
  • It will ask you to now select a profile.
  • Press Enter.
  • Type in ‘0’.
  • Press Enter.
  • Press the Menu button three times to reach the main window.
  • Press the S/S button two times.
  • Shut down:
  • Turn off the control power switch.
  • Log out of CRESS

End of process.

Cooke Annealer procedure-1-12/02/15

Troubleshooting:

See the staff if you are having trouble with this tool.

Appendix:

Mounting a Sample Using Wafer-Mount 562

  1. Choose a pre-cut piece of Wafer-Mount 562 that will fit under your sample that you are trying to attach to a carrier. The Wafer-Mount 562 is 50um thick.
  2. Place the Wafer-Mount 562 on your carrier substrate and then position your sample on top of it.
  3. Follow the Cooke Vacuum Anneal procedure to run recipe #13.
  4. To remove the Wafer-Mount 562 after its use has ended you can remove it by reheating on a normal hot plate to 95C and/or it dissolves in acetone.

Mounting a Sample Using PR 1827

  1. Go into Lithography Bay and find the PR 1827 sample mounting kit in the metal PR cabinet at the end of the bay.
  2. Use a spin coater or pipette to apply the 1827 to your carrier substrate. If just using a pippette to apply the 1827 put the bare minimum on the carrier, usually the little bit suspended on the end of the pippette is enough.
  3. Place your sample on the liquid 1827. Optimally when you put your sample on top of the 1827 you do not want any squeezing out from underneath. Also, larger substrates (usually 2” or bigger) when pumping down under vacuum may slide across the 1827 and carrier, so if that is the case there is a small weight in the mounting kit that you can put on your sample to keep it still while the Cooke pumps down.
  4. When done applying the 1827 and your sample to the carrier substrate put the mounting kit back in the PR cabinet at the end of the bay.
  5. Go back to Packaging Bay where the Cooke Vacuum Anneal system is and use the operating procedure to run recipe #9 on your 1827 mounted sample.
  6. To remove the PR 1827 after its use has ended you can remove it using acetone, a PR stripper, or sulfuric acid.

Cooke Vacuum Annealer Recipes

Cooke Annealer procedure-1-12/02/15