Lithography

Two methods to apply HMDS coating on:

1. YES Vapor Prime Oven protocol coat

2. 20% HMDS spin coating with the following recipe:
I) Speed: 250 RPM, Ramp: 250 RPM/s, Time: 5 seconds
II)Speed: 2000 RPM, Ramp: 700 RPM/s, Time: 35 seconds
III)Speed: 0 RPM, Ramp: 1000 RPM/s, Time: 7 seconds

Operating the contact aligner:

1. Turn on the power supply located under the bench
   1. If not turning on flip breaker- press and hold start
   2. Wait 30 min and try again
2. Turn on the power to the aligner
3. Turn on the nitrogen
4. Turn on the vacuum
5. Test intensity of the bulb
1. Place the intensity meter on top of the chuck
2. Set exposure system to manual
3. Move exposure system to “expose” position (switch locate on the right side of the aligner)

Headway Spinner Bench
Operating Instructions

1. Place tin foil, orange absorbent pad or cleaning wipe in the spin bowl to keep bowl clean.
2. Choose 3”, 4” or small chuck and make sure chuck has O-ring in place for vacuum suction. Place the chuck in the spinner bowl making sure the flat edge of the chuck is aligned with the flat edge on the connection, and fully press the chuck in the bowl.

Brewer Spinner Bench
Operating Instructions

1. Using alignment fixture, load and center wafer on chuck: Alignment fixture can be adjusted for 3” and 4” wafers.
2. Choose desired recipe by pressing ‘OPT.’ button until ‘CEE 100CB AUTO DISP’ appears on screen.
3. Press ‘RUN’ button followed by the number of the desired recipe and then ‘ENTER’. Coater will rotate wafer and ask to verify wafer centering.
4. Press ‘START’ when ready to begin spin coating and dispense photo resist at appropriate time in spin recipe.

Photolithographic Process for S 1813 Positive Photoresist on Al Coated Si Wafer

1. Clean Al Coated Wafers
   1. Heat AZ KWIK Strip Remover to 60 °C.
   2. When bath is at temperature, place wafer in dish and start 10 minute timer.
   3. When time is complete, take wafer out of KWIK Strip and wash off with deionized water. Blow dry with nitrogen gun.
2. Dehydration Bake
   1. Place cleaned Al coated Si wafer on vacuum hot plate, and perform a dehydration bake for 10 minutes at 150 °C. Let the wafer cool to room temperature after bake.
3. Spin Coat Wafers with S 1813.

Photolithographic Process for AZ 1512 Positive Photoresist on Bare Silicon Wafer

1. Clean Wafers with Piranha Etch Bath.
   1. Heat bath to 80 °C.
   2. When bath is at temperature, place wafers in sulfuric acid bath using Teflon boat and start 20 minute timer.
   3. When time is complete, take wafers out of piranha etch and place in dump washer being careful to avoid any drips of sulfuric acid. Start the timer on the dump washer.
2. Dehydration: 120°C baking for 10 mins
3. Adhesive promotor coating: Programmed HMDS coating (Program 1)
4. Spin coating:(Note. To ensure adhesive promotor active, start PR spin coating right after HMDS coating.) 
   1. Dispense sufficient amount of AZ 1512 from the center of the wafer covering 60% - 70% of the wafer surface.
   2. Spin at 500 rpm for 20 seconds to spread out the photoresist.
   3. Spin at 4000 rpm for 35 seconds to reach 1.3 micrometer in thickness. (+ or – 476 nm)
5. Soft Bake: 110°C (1 min)
6. Exposure: 2.4 seconds with expose dose 40 mJ.
7. Develop:
   1. 50 seconds gentle agitation in AZ 300MIF solution.
   2. (Optional) Stir the wafer slightly to remove red PR residue floating on top of wafer.
8. Rinsing: Dip into water to remove developer
9. Dry: Blow dry the wafer with compressed Nitrogen gun. 

Photolithographic Process for AZ 3312 Positive Photoresist on Bare Silicon Wafer

1. Clean Wafers with Piranha Etch Bath.
   1. Heat bath to 80 °C.
   2. When bath is at temperature, place wafers in sulfuric acid bath using Teflon boat and start 20 minute timer.
   3. When time is complete, take wafers out of piranha etch and place in dump washer being careful to avoid any drips of sulfuric acid. Start the timer on the dump washer.
2. Clean and Dry Wafers in Semitool SPD015 Spin Dryer
   1. Upon completion of dump washer, place wafers in spin dryer and press start.

Photolithographic Process for AZ 3312 Positive Photoresist on Aluminum Coated Substrates

1. Clean Al Coated Substrates
   1. Heat AZ KWIK Strip Remover to 60 °C.
   2. When bath is at temperature, place Al coated substrate in dish and start 10 minute timer.
   3. When time is complete, take substrate out of KWIK Strip and wash off with deionized water. Blow dry with nitrogen gun.
2. Dehydration Bake
   1. Place cleaned Al coated substrate on vacuum hot plate, and perform a dehydration bake for 10 minutes at 150 °C. Let the substrate cool to room temperature after bake.

Photolithographic Process for AZ 3312 Positive Photoresist on Chromium Coated Substrates

1. Clean Cr Coated Substrates
   1. Heat AZ KWIK Strip Remover to 60 °C.
   2. When bath is at temperature, place Cr coated substrate in dish and start 10 minute timer.
   3. When time is complete, take substrate out of KWIK Strip and wash off with deionized water. Blow dry with nitrogen gun.
2. Dehydration Bake
   1. Place cleaned Cr coated substrate on vacuum hot plate, and perform a dehydration bake for 10 minutes at 150 °C. Let the substrate cool to room temperature after bake.

Photolithographic Process for S 1813 Positive Photoresist on Bare Silicon Wafer

1. Clean Wafers with the Piranha Etch Bath.
   1. Heat bath to 80 °C.
   2. When bath is at temperature, place wafers in bath using Teflon boat and start 20 minute timer.
   3. When time is complete, take wafers out of piranha etch and place in dump washer being careful to avoid any drips of sulfuric acid. Start the timer on the dump washer.
2. Clean and Dry Wafers in Semitool SPD015 Spin Dryer
   1. Upon completion of dump washer, place wafers in spin dryer and press start.

Photolithographic Process for S 1805 Positive Photoresist on Bare Silicon Wafer

1. Clean Wafers with the Piranha Etch Bath.
   1. Heat bath to 80 °C.
   2. When bath is at temperature, place wafers in bath using Teflon boat and start 20 minute timer.
   3. When time is complete, take wafers out of piranha etch and place in dump washer being careful to avoid any drips of sulfuric acid. Start the timer on the dump washer.
2. Clean and Dry Wafers in Semitool SPD015 Spin Dryer
   1. Upon completion of dump washer, place wafers in spin dryer and press start.