Curated with aloha by
Ted Mooney, P.E. RET
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Etching solution for Tantalum/Tantalum Nitride
Q. I am trying to find an etch that will etch tantalum and/or tantalum nitride with some selectivity to copper. I've tried various mixtures of HF and H202, but they all rapidly attack the Cu. Does anyone know of any additional wet etches for tantalum or more specifically tantalum nitride?
David ArnoldGeorgia Tech - Atlanta, Georgia
2002
A. Try H202 and EDTA. This will strip titanium nitride and since tantalum is also a refractory group metal I think it would also work.
Jon Quirt- Fridley, Minnesota
2002
! I tried EDTA and H202, and it works quite well. I mixed 1:1 0.5M EDTA and 30% CMOS grade H202. It took 1 hr. to etch ~2000A Ta at 60° C. The Cu structures bubbled some (not sure of the etch rate), but remained intact.
Thanks.
David ArnoldGeorgia Tech - Atlanta, Georgia, USA
2002
Q. I tried out the 1:1 proportion of 0.5M EDTA and H2O2 (but I'm using 35%), but my Ta film of 300A is still intact. Anyone know why? Please enlighten me.
Edmund Lim- Singapore
2003
A. Was the etchant at elevated temperature? I use 1M EDTA:H202 1:1 at 60° C and get an etch rate of ~1000-2000A/hr. Be patient.
David ArnoldGeorgia Tech - Atlanta, Georgia, USA
2003
Q. I bought a bottle of EDTA (Ethylenediamine Tetraacetic acid ⇦ this on eBay or Amazon [affil links] ). It is not dissolve in what. Then how do you make the 0.5M EDTA?
Jun Lusemiconductors - Ottawa, Ontario, Canada
2007
June 6, 2012
Q. We have been asked to etch a .003" tantalum component. Initial research recommends a 1:1 HF/Nitric acid bath. We have been unsuccessful to date (resist gave prior to achieving depth). Any recommendations on formula or process?
Ace Sawqnack- Buffalo, New York, USA
A. Hi Ace.
As you see, we appended your inquiry to an earlier thread about etching tantalum. You might also look at letters 5648 and 22882, or try the Google custom search engine. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
June 7, 2012
July 13, 2012
A. What is the purpose of tantalum etching? If not grain revealing, then you will probably prefer tantalum electropolishing in less hazardous electrolytes. The surface will be smooth and bright.
Anna Berkovich
Russamer Lab
Pittsburgh, Pennsylvania
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