Specific Process Knowledge/Etch/Etching of Titanium

Etching of Titanium

Etching of Titanium is done wet at Danchip. We have two solutions for titanium etching:

1. BHF
2. Cold RCA1 (as stripper)

Do it by making your own set up in a beaker in a fume hood - preferably in cleanroom 2 or 4. BHF etching can also take place in the PP-etch bath in the fume hood in cleanroom 2.

Comparing the two solutions

	BHF	Cold RCA1
General description	Etch of titanium with or without photoresist mask.	Etch of titanium (as stripper)
Chemical solution	HF:NH$_{4}$F	NH$_{3}$OH:H$_{2}$O$_{2}$:H$_{2}$O - 1:1:5
Process temperature	Room temperature	Room temperature
Possible masking materials	Photoresist (1.5 µm AZ5214E)	None
Etch rate	Not known (it bubbles while etching)	Not known
Batch size	1-5 4" in beaker 1-25 wafers at a time in PP-etch bath	1-5 4" wafer at a time
Etch bath	Beaker or PP-etch bath in the fume hood in cleanroom 2.	Beaker
Allowed materials	No restrictions when used in beaker or PP-etch bath in the fume hood in cleanroom 2. Make a note on the beaker of which materials have been processed.	No restrictions when used in beaker. Make a note on the beaker of which materials have been processed.