Gold Shuttle

Goal: run an MVP shuttle run and bring wafers to open sauce 2026

TODO:

• Document existing fabrication process better
• Set back up in SF
  • Grab ez bake litho system out of storage
  • Acquire lab space (WIP)
  • Fix sputter coater
• Measure maximum resolution
• Make PDK
• Wafer floorplan
  • Probably 3x3
• Solicit first cohort of contributors
  • Start by sourcing from FOSSF discord

Previous work

Above: IIRC used this, but a UVC PR would probably also work

Equipment used:

• Maasi spin coater
  • Production used 2, but you can get away with 1
  • Production configuration: 1 for cleaning, 1 for PR
• "ez bake lithography" exposure machine
• Masks
  • 3d printed frame + transparency
• Printer
  • I used a laser printer

Simple / existing gold fabrication process:

• Mask fabrication
  • Laser printer a couple of times through onto transparency
  • Cut to size
• Clean 2" wafer
  • Strip photoresist by leaving it in for longer
  • Clean with IPA and spin at max speed (8k RPM)
  • Sometimes lightly brushed wafer when needed
• Sputter coat gold
• Spin coat PR
• Expose mask
• Develop PR using KOH
• Etch gold using NaI/I
• Clean wafer
• Place into membrane box

Mask exposure using "ez bake lithography"

Some early notes from that can be found here

There are