Advanced Materials for Electronics


Transene Ruthenium Etchant RU-44 is a ceric ammonium nitrate / nitric acid etching solution for all types of evaporated ruthenium films. Etch rate will depend upon substrate ruthenium density and process conditions. In general, the etch time usually ranges from 15 to 55 seconds at room temperature (25°C). The etchant can be supplied with an added surfactant (Ruthenium Etchant RU-44S ). Ruthenium Etchant RU-44 is suitable for sub-micron photolithography applications. For faster etch results, Transene Chromium Cermet Etchant TFE may be used.

Storage and Handling:

Store at room temperature away from direct sunlight, keep container sealed when not in use. This is an acid oxidizing solution and should be handled with caution. In case contact is made to eyes or skin, flush with large quantities of water and contact a physician if irritation persists.


How do I increase the etch rate? 1. The rate will approximately double with every 10°C increase in temperature.
2. Increase the rate of stirring or agitation.
How do I reduce the etch rate? Adding 1 part deionized water to 2 parts etchant will reduce the etch rate approximately 50%.
Do I need to dilute the etchant? No, it is ready to use.
How do I reduce undercutting? Increase the rate of stirring or agitation.
Appearance Clear orange
pH Acidic
Etch Rate at 40°C 40 Å/sec.
Etch Capacity (rate declines at ~70%) 65 g/gallon
Shelf Life 1 year
Storage Conditions Ambient
Filtration 0.2 um
Recommended Operating Temperatures 20-80oC (30-40oC most common)
Rinse Deionized water
Photoresist Recommendations PKP-308PI or HARE SQ (SU-8 type)
Select Compatible Materials Au, Ti, oxide, nitride, Si

See for more details.

Select Incompatible Materials Al, Ni, Cu, NiCr, Cr
Compatible Plastics HDPE, PP, Teflon, PFA, PVC
Country of Origin USA
Availability 1-2 days
Available Sizes Quart, Gallon, 5 Gallon, 55 Gallon
Packaging HDPE
Packing 4 gallons/case
Isotropy Isotropic
Incompatible Chemicals Strong bases
Additional Information