Resist spinner     EMS SpinCoater Model 4000

Responsible: Anders Liljeborg, Erik Holmgren Adrian Iovan

The Spinner is used to spin a resist layer on a chip or wafer. It is manufactured by Electronic Micro Systems (EMS), England. It consist of a controlling unit and the spinner placed inside the clean-air bench.

The spinner inside the clean-air bench. Note there is a protective paper
inside the spinner to keep resist from collecting on the walls.
To the left are different resist containers.

The spinner is started with the green button and stopped (before spin-program end) with the red button. Note that the vacuum pump has to be started before any spinning can be done. The chip/wafer is held on the chuck with vacuum. The switch for the vacuum pump is located on the outer right wall of the clean-air bench.

NEW! Use sticky pad to avoid resist sucked to backside of chip!

There are different chucks for different chip/wafer sizes. Here the spinner is shown with the smallest chuck for centimeter sized chips. There are also chucks for 2, 3 and 4 inch wafers.

Note! The spinner should always be run with a protective and lint-free paper in the bowl to prohibit resist to collect inside the bowl.

The spinner controlling unit.
From left to right: power switch, rotation speed indicator (RPM × 10),
vacuum control switch, keypad, text window, digital output indicators.

The controlling unit is where the programming of the spin sequence is done. A spin sequence (program) can consist of up to eight different steps, each with a different acceleration, speed and duration. Usually it is sufficient with two steps, one for applying the resist and let it spread uniformly over the chip/wafer, and the next step to do the actual spinning of the resist at high speed to the desired thickness.

Note! The maximum speed of the spinner is 6000 RPM.

The vacuum switch can usually be left in the Automatic position, i.e. the vacuum is automatically turned on before start of spin and shut off when chuck is still.

The user interface is perhaps not crystal clear, there are some labels added around the keypad to help the user.

• "D", Step, is used to step between different functions and (when entered into a function) step between different sub-entries.
• "E", Enter, is to validate a changed parameter.
• "C", Esc, is to escape out of a function or entry.
• "B", Decr, decrements the current variable.
• "A", Incr, increments the current variable.
• Number buttons, used to enter new value for current variable.

• Program menu
  Used to store and fetch spin-programs.

  2021-01-30: The memory circuit was replaced due to battery exhausted. Program locations 1 - 5 are now programmed for speeds 2000, 3000, 4000, 5000 and 6000 rpm, all with 20 sec dwell time. This can be modified by any user. Please check the parameters before using a program.

  There are program locations from 1 - 99, currently no personal allocation is made of these locations.
  One press on "E", Enter will take you into two submenues:

  • Fetch program
    - enter program number, press Enter.
    or press "D", Step to get to next submenu:
  • Store program
    - enter program number, press Enter.

  You can always "escape" to the start by pressing "C", Esc. The same applies for all steps below.

• Start & Stop menu
  • Number of steps in sequence
    This is set to two (2), usually not changed.
  • Start delay (seconds) - set to two (2), should not be changed.
  • Stop delay (seconds) - set to one (1), should not be changed.
  • Final ramp, should not be changed.

• Edit step 1
  Parameters for first spin step.
  • Speed
    Note that this speed entry should be multiplied with 2.5 to get the actual RPM value!!
    I.e. all values entered here should be 2.5 times smaller than the desired RPM value.
    - usually between 50 - 120 RPM (20 - 48)
  • Dwell time
    - usually 2 - 5 s. Depends on resist.
  • Ramp (acceleration)
    set to 50, should not be changed.
  • Outputs
    These need not be changed, just press Enter three times to get the default value. Then press Esc to return to the top menu Program menu.

• Edit step 2
  This is exactly the same as for step 1. Here is usually the spinning of the resist done to achieve the desired layer thickness.
  • Speed
    - usually between 1000 and 6000 RPM (400 - 2400), value taken from spin-curve for the resist used.
    Remember factor of 2.5.
  • Dwell time
    - usually 60 - 75 s., depends on which resist is used.
  • Ramp (acceleration)
    - usually 50.
  • Outputs
    - same procedure as for step 1.

• Edit steps 3 - 8
  These are exactly that same as for steps 1 and 2, but they are not used if the number of steps is set to two under the Start & Stop menu.

Here is one page from the manual included, showing the menu structure.

Estimate of ramp (acceleration) parameter

All tests were done going from 0 to 3000 RPM.

All time estimates are very rough, especially the shorter times, since this was done completely manually.