Etching Manifesto
What to etch with
Item | Etchant | Notes |
|---|---|---|
Coated Viewports | NH4OH:H2O2:H2O (1:1:1) | NH4OH:H2O2:H2O is the industry standard for etching viewports. However, the glass-to-metal seal is degraded with exposure. So, it's suggested to use very dilute solution on a kimwipe (or a swab) and rinse frequently to keep it off of the seal. |
pBN (Shutters and Crucibles) | HCl:HNO3:H2O (3:1:1 or 3:1:0, skewed aqua regia) | Tweezers: Delrin |
Ta Shutters | Aqua regia (??? Although Wiki says it's OK) | Tweezers: Delrin |
Stainless Parts | Likely pickling (??? Should remove both III and III-V) | Tweezers: Delrin |
RHEED Screen | H2O2 | Suspend over a beaker of peroxide |
Al-coated molybdenum | HCl:H2O | Place part in polypropylene container. Pour HCl over the part (cleanroom supplies 37%). Can dilute further with DI water. Slosh around in a fume hood until aluminum is etched away. Does fume (likely hydrogen gas), so work in a fume hood. Rinse clean with DI water into another container and do the treatment if it is a vacuum part. |
Recipes
Pickling (cleaning SS)
Ace, Meth, IPA, DI rinse, Formic:Peroxide:DI (1:1:10), DI rinse Tweezers: stainless steel for solvents, Delrin for acids
The Treatment
20 min each of ultrasonic: Micro-90, DI rinse (x3), ace, meth, ipa
Tweezers: stainless steel
Other Etches
Uni-block and Faceplate Etching
hydrochloric/perox/water (trace metals)
ammonium hydroxide/perox/water (trace organics)
HCl:H2O – aluminum, specifically, and other group IIIs