Chromium Etch 1020

Chromium Etch 1020 is a ceric ammonium nitrate/ nitric acid based etchant that is used to etch chromium at a rate of 13Å/sec or 750A/min. This chemical is manufactured by Transene. This etch was brought in to replace the discontinued Cr-14. In appearance, it is bright orange in colour.

Chromium Etchant 1020 is noted to have the least undercut and a longer shelf life in comparison to other Chromium etching chemicals.

Equipment

• Acid Bench 12: Maintained tank
• Mask Bench 13: Maintained tank
• Acid Bench 72: No maintained tank or beakers
• Acid Bench 73: Maintained beaker
• Acid Bench 82: No maintained tank or beakers

Hazards

There are many hazards associated with working with Chromium Etch. Please be aware of these before working with chemicals:

Chemicals

Hazardous chemicals used for process:

Ceric Ammonium Nitrate : CAS # 16774-21-3

Nitric Acid : CAS # 7697-37-2

SDS

Properties

Transene Chromium Etchant 1020 has the following properties:

• High purity
• 0.2 micron filtration
• Excellent photoresist compatibility
• Uniform etch rates and patterns.
• Appearance: light orange
• pH: acidic
• Compatible Plastics: HDPE, PP, Teflon, PFA, PVC

Safety

Chromium etch 1020 is corrosive and an irritant. Please read over the SDS to know important safety procedures before using any process.

Collection

Chromium etchant is toxic to aquatic life, thus needs to be collected to Hazardous waste and disposed of via EHS rather than aspirated. If you believe that the chromium etch in Mask Bench 13 or Acid Bench 12 needs to be changed, please contact staff by making a ticket.

Processes

• See more information at the Transene website: https://transene.com/cr/

Compatibility

See https://transene.com/etch-compatibility/ for more details.

Metal Compatibility

• Al - Etch
• Al2O3 - > 20:1 selectivity
• Ag - > Etch
• Au - > 20:1 selectivity
• C - etch
• Co - Etch
• Cr - Etch
• Fe - < 20:1 selectivity
• GaAs - Etch
• Mg - Etch
• MgO - Etch
• Nb - > 20:1 selectivity
• Ni - Etch

Safety Data Sheet

• Chromium Etch 1020

References

• KR Williams, K Gupta, M Wasilik, "Etch Rates for Micromachining Processing - Part II", JMEMS vol. 12 No 6, Dec 2003
• Vossen, John L., and Werner Kern. Thin Film Processes. Academic Press, 1991.