Specific Process Knowledge/Etch/Etching of Chromium

Etching of Chromium

Fume hood: positioned in cleanroom 2.
Wet Etch of Chromium can take place in a beaker in this fume hood

Etching of chromium is done wet at Danchip making your own set up in a beaker in a fume hood - preferably in cleanroom 2 or 4. We have two solution for this:

1. HNO$_{3}$:H$_{2}$O:cerisulphate - 90ml:1200ml:15g - standard at Danchip
2. Commercial chromium etch

Etch rate are depending on the level of oxidation of the metal.

Overview of the data for the chromium etches

	Chromium etch 1	Chromium etch 2
General description	Etch of chromium	Etch of chromium
Chemical solution	HNO$_{3}$:H$_{2}$O:cerisulphate - 90ml:1200ml:15g	Commercial chromium etch CE 8002-A
Process temperature	Room temperature	Room temperature
Possible masking materials	Photoresist (1.5 µm AZ5214E)	Photoresist (1.5 µm AZ5214E)
Etch rate	~40-100 nm/min	~10-20 nm/min
Batch size	1-25 wafers at a time	1-25 wafer at a time
Size of substrate	4" wafers	4" wafers
Allowed materials	No restrictions. Make a note on the beaker of which materials have been processed.	No restrictions. Make a note on the beaker of which materials have been processed.