Specific Process Knowledge/Etch/Etching of Gold
Etching of Gold
Etching of Gold is done wet at Danchip making your own set up in a beaker in the fumehood. We have two different solutions:
- Iodine etch: KI:IFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle _2} :HFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle _2} O - 100g:25g:500ml - standard at Danchip. Can be used with resist as mask.
- Aqua Regia (Kongevand): HNOFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle _3} :HCl - 1:3 - It is a very strong acid witch will etch most metals and are therefore used when you wish to remove all the gold from your wafer. Be very carefull when you work with Aqua Regia (Kongevand) It can generate nitrous gases witch are very toxic!!
Comparing the two solutions
| Iodine based gold etch | Aqua Regia (Kongevand) | |
|---|---|---|
| General description |
Etch of pure Gold |
Etch of pure Gold |
| Chemical solution | KJ:JFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle _2} :HFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle _2} O (100g:25g:500ml) | HCl:HNOFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle _3} (3:1) |
| Process temperature | 20 oC | 20 oC |
| Possible masking materials |
Photoresist (1.5 µm AZ5214E) |
Unmasked - used as a stripper |
| Etch rate |
~100 nm/min |
~(??) nm/min - fast etch |
| Batch size |
1-25 wafers at a time |
1-25 wafer at a time |
| Size of substrate |
2-6" wafers |
2-6" wafers |