Specific Process Knowledge/Etch/Etching of Chromium

From LabAdviser

Wet etching of Chromium

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

Wet etching of chromium at Danchip is done 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:HO:cerisulphate - 90ml:1200ml:15g - standard at Danchip
  2. Commercial chromium etch

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

How to mix the Chromium etch 1:

  1. Take a beaker and add 15g of cerisulphate.
  2. Add a little water while stirring - make sure all lumps are gone.
  3. Add water until 600 ml - keep stirring (use magnetic stirring)
  4. Add 90 ml HNO
  5. When the cerisulphate is completely dissolved (clear liquid) you can add the other 600 ml of wafer.



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:HO:cerisulphate - 90ml:1200ml:15g .
Process temperature Room temperature .
Possible masking materials

Photoresist (1.5 µm AZ5214E)

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Etch rate

~40-100 nm/min

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Batch size

1-25 wafers at a time

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Size of substrate

4" wafers

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Allowed materials

No restrictions. Make a note on the bottle of which materials have been processed.

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Dry etching of chromium

On the ICP Metal Etch tool a recipe for chromium is being developed.