Specific Process Knowledge/Etch/Etching of Chromium

Etching of Chromium

Etching of chromium is done wet at Danchip. We have two solution for this:

1. HNO${}_3$:H${}_2$O:cerisulphate - 90ml:1200ml:15g
2. Commercial chromium etch

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

	Chromium etch 1	Chromium etch 2
General description	Etch of chromium	Etch of chronium
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	Aluminium Silicon Silicon Oxide Silicon Nitride Silicon Oxynitride Photoresist E-beam resist	Aluminium Silicon Silicon Oxide Silicon Nitride Silicon Oxynitride Photoresist E-beam resist