Kimwipe: KW; LASE paper kimwipe: LPKW.

Note: Read this before running process

Note: Some diagrams will not show up on Wiki

Solvent Clean Notes

Beakers

• Put beakers only on your KW or in sink if rinsing

Tweezers

• Inspect tweezers before each use

• Do not put tweezers down ever, except in proper boat

  • Never lay on wipes

• If tweezers touch normal wipes or dirty things, switch tweezers

• Try not to touch tweezers to basket (what about the tip?), especially tweezer handles (where you touch)

• Can use one tweezer for full litho process if no problems

• Do treatment on tweezers after every run

Boats

• Make a boat with a lid (separate piece) and at least one strong corner.

• Make a bigger boat for more samples.

• Glove and wipes can touch outside of boat

• Remake tweezer boats each time you clean tweezers (after every run)

Dipper

• Do not touch the dipper basket!

• Dipper only goes in beakers and on LPKWs

• Avoid dipper handle getting wet during cascade rinse, if possible

  • It can knock junk into the beaker and sample

Samples

• Sample only belongs in boat, dipper, or tweezers

• Can lay sample down on LPKW only if you think you can pick it up

• Can grab anywhere on edge with tweezers, grab it securely

• Can touch one of these three corners to LPKW for water removal when drying

  • The central wafer sample tip can touch LPKW.

• Can put sample in boat when drying to pause, if mostly dry

  • N2 dry tweezers when you do so

• Don’t get liquid in the boat

Regrowth Litho w/ VDD (8-22-2014)

• Make a boat with a cap

• Prep bench (e.g. J24) with KW like normal then put down LPKWs on 2/3 of bench.

  • Get stack of LPKW place them down then shift them around

  • Timer doesn’t go on LPKW

  • Boat only goes here (on LPKW) first time of process (solvent clean)

• ACE, IPA, DI 3 min each

  • Take off top layer of LPKW while sample is rinsing.

• After rinses, pour some/all water out of beaker and move beaker (with dipper in it) to work area edge

• Place dipper onto LPKW

• Don’t blow boat away when drying

• Drying technique: carefully lift up sample in dipper but don’t remove

  • Blow off majority of water

  • Remove from basket and dry more. The central wafer sample tip can touch LPKW.

  • Change tweezer position by putting sample in boat and repositioning (dry tweezers here too)

  • Continue drying and place in boat when done

• Dehydration bake, 150 C oven – 5 min

• Make spinner bench wipe friendly w/ LPKWs

• Use not small sample chuck, kind of medium sized

• Test spinning with dummy ¼ wafer

• Don’t touch tweezers to chuck

• Solvent clean dummy quarter wafers after test spinning (did we do that?)

• Spin on PR AZ5209E, 5 krpm, 30 sec

• Pre-exposure bake, 90 C oven – 6 min

• Wipe MJB4 chuck with IPA, use the large one big enough for these quarter wafers

• Pay attention to wafer flat and position

• Want to etch along (11-0) AKA (1-10) (bar over middle number).

• SI-GaAs wafers

  • Epi up

  • Keep track of which SiNx side/color is up and down, esp for QI qtr

  • Etch Parallel to Major, perp to minor flat

• Take your time to align mask

• Use underlining the UTexas text across the sample and multiple zoom levels

• Expose – 16 sec

• To clean mask, squirt with acetone (over waste beaker) and dry with N2. Do so periodically.

• Develop is pretty normal, but with LPKW setup.

• AZ 726 MIF – 15 sec

  • Take off top layer of LPKW while sample is rinsing.

• Dry sample and put in wafer puck/sample holder

• Clean up

• Litho tweezers are now done and dirty

Acid Etch Hardmask (9-23-2014)

• Make sample boat with lid

• Set KW on nearby table for prep area

• Take out all samples and supplies and put on KW

• Put sample into ultraclean sample boat with lid

• Clean+dry bench if needed, it shouldn’t be but probably is

• Layout KW on acid bench (as usual)

• Have KW off to the side too for sample boat and timer (as usual)

  • Only put beakers and sample boat onto KW (as usual)

• Put dipper into rinse beaker for now

• Put down LPKW before prepping beakers

• Move other supplies into bench on KWs

• Put sample in dipper

• Put dipper on LPKW

• Prep beakers with rinse water and BOE (6:1, straight)

• Etch – 60 sec

  • jiggle occasionally

• Rinse – 5 min

• When rinse is done, move rinse beaker to a KW

• Pour out etch beaker and triple rinse

• Pour out rinse water

  • Take off top layer of LPKW

• Sample only goes in sample boat, in dipper, over dipper, and with one corner touching LPKW

• Put dipper onto LPKW and blow dry big droplets off sample

• Now hold with tweezers in basket (or over basket but low) and blowdry

  • Should be mostly dry

• Can use sample boat to help shift tweezer grip when nearly dry

• Can put a point down on LPKW to dry more, don’t go crazy

• Do not touch the sample with the N2 gun!

• Can put it nearly dry into sample boat and continue drying in LASE lab

• Rinse out rinse beaker

• Rinse off sides and bottoms of beakers and shake dry

• Dry off beakers on wipes; outside of bench (at your prep area) OK

• Remove PR between SiN hard mask etch and GaAs V-groove etch

Acid Etch V-Grooves (9-24-2014)

• Standard solution is H2SO4:H2O2:H2O 1:8:1

• (we also tried 3:8:1 and 3:8:3)

• Decide on liquid volume amounts beforehand

• Put samples into boat

• Put dipper into empty rinse beaker

• Measure and pour water into etch beaker

• There are large and small beakers for H2SO4 and H2O2

  • There are 7 beakers (H2O, H2SO4 big and small, H2O2 big and small, Etch, Rinse)

• Pour chemical into the large chemical beaker, about the amount you need

• Pour large beaker into small beaker, measuring the amount you need

• Combine into etch beaker

• Put dipper onto LPKW and samples into dipper

• Fill Rinse beaker with water

• Perform etch

• Rinse – 5 min

• Dry carefully

• Clean beakers and workspace