Full process

1. Solvent user safety All wipes that have been used with solvents should

• Room 128: put in dustbin inside fume hood
• Room 129: put in small dustbin with lid. Transport to fume hood in room 128 when finished

2. Turn on hot plate 1(20 min before wafer cleaning)

Equipment needed:

• VWR spec-wipe wipers
• Isopropanol

Procedure

• Open LAF bench
• Wipe off the hot plate with VWR spec-wipe wipers and isopropanol clean [VWR hot plate]
• Power on VWR hot plate and set its temperature 150 celus degree.

3. Cleaning of wafer

Equipment needed:

In room 128:

• Wafer
• Wafer tweezer
• Glass petri dish
• Acetone in spray bottle
• Isopropanol in spray bottle

Procedure:

In room 128 fume hood

• Rinse with acetone
• Put wafer in glass petri dish with isopropanol before acetone has vapourized
• Rinse glass petri dish with isopropanol [Repeat the process several times - rinse with isopropanol]
• Dry with nitrogen gun
• Transport to LAF bench in room 129
• Put on hot plate, keep lid off
• Leave the wafer on the hot plate until the temperature (red number - stable number) has been stable above 140 C for 5-10 minutes.
• Turn off the hot plate so it may start cooling for next step

4. Program spin coater [GM1070 datasheet]

• Power on and vacuum switch to “manual”
• Look up in table spin speed for desired thickness
• Check the wiki if there is a spin program with the procedure and speed you want
• Choose appropriate program or make a new one (note on wiki what the new program is)
• Go through the program to check that it is correct
• Put the correct choke on the spinner
• Put the test wafer on the choke and close the lid
• Turn on the vacuum pump
• Push the blue button to run the spin sequence and verify the sequence
• Turn off vacuum pump (if desired)

Put on a wasted waffer to test and make sure the program is correct

Spin coater: To get a good results, should spin two step, one low speed to spread PR over the wafer and 1 high speed to reach the thickness. When pour PR, avoid bubbles, should pour more PR volume to cover all the wafer) (test today: 10s at 500, 40s at 900, ramp 100)

5. Spin coating SU8 on wafer

Preparation:

• Look up in table how much SU8 must be applied depending on the size of the wafer and the desired layer thickness
• Turn off white light in room 127, 128 and 129, turn on yellow light and move down the blinding curtains.

Equipment needed:

• SU8
• Disposable container or syringe

Procedure:

• Put wafer on chuck (well centred)
• Turn on vacuum (to fix wafer on chuck)
• Transfer desired amount of SU8 from bottle to disposable container
• Transfer desired amount of SU8 from disposable container onto centre of wafer
• Close the lid and push blue button
• Turn off the vacuum
• Leave the wafer in the spin coater with the lid on for [~1 hour for relaxation] - Based on the process

Prebake

• Check that the hot plate temperature is below 50 C
• Set the time parameter in the hot plate program to that suitable for your thickness
• Press “P” to go through the parameters of the program
• Turn off white light, turn on yellow light
• Remove wafer from spin coater and remove any SU8 from the underside of the wafer
• Put wafer on hot plate (on top of aluminium foil) and close lid
• (turn off yellow light if desired)
• Press “U” to start the program (green dot behind green number should light up)
• After program has finished

• Alternative 1

Leave the wafer under the lid in the hot plate until the temperature is less than 50

Turn off white light, turn on yellow light

Open lid, move wafer to Teflon slab

Let the wafer cool for XX minutes

• Alternative 2

Turn off white light, turn on yellow light

Open lid, move wafer to Teflon slab

Let the wafer cool for YY minutes

Prepare the mask during prebake

• Open and turn on the LAF bench (and leave it on)
• Take the transparency mask out in the LAF bench
• Clean a mask glass [isopropanol in room 128] and place it on centering pattern
• Cut out your pattern
• Put the reflecting side of the film towards the glass [the printed inside attach to waffer, check the edge to find out the ink side]
• Place the mask in the centre of the glass and fasten with two small pieces of tape

Exposure

• Keep white light off, yellow light on
• Calculate UV-KUB settings
• Turn on the UV-KUB (power button behind and in front)
• Open drawer (how)
• Move wafer from Teflon slab to UV-KUB
• Put glass with mask on top (mask should contact wafer)
• Close drawer
• White light can be turned on
• Set UV-KUB settings
• Expose
• Leave the wafer to relax inside UV-KUB for 5-10 minutes

Postbake

• Change the hot plate settings to post-bake or leave the settings to remove manually after 40 minutes at 95 C
• Wait until hot plate temperature is less than 35 C
• Turn off white light, on yellow light
• Move wafer to hot plate
• White light can be turned on
• Run program…….
• 10 min relaxation

Development

• Turn off white light in room 128 and 129, yellow lights on - put the light off sign on the door - 127
• Pour the PGMEA into beaker in the fume hood in room 128
• Move wafer to fume hood in room 128
• Place wafer in wafer holder
• Set timer to XX minutes (calculated from…)
• Put wafer holder with wafer into PGMEA at the same time as the timer is started
• When timer beeps take wafer out and rinse with isopropanol
• Dry with nitrogen
• Put wafer under stereo microscope (outside the fume hood - room 128)

Hard bake (white light is OK)

• Put the wafer in a glass petri dish to keep dust off
• Put dish with wafer in cold oven
• Turn temperature set point to 135 C
• Leave it in the oven for 3 hours and let it cool slowly