Specific Process Knowledge/Etch/Wet III-V Etches: Difference between revisions
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It is very important that you dispose off chemicals and process waste according to DTU Nanolab regulations and risk assessments for your work. | It is very important that you dispose off chemicals and process waste according to DTU Nanolab regulations and risk assessments for your work. | ||
'''For the GaAs and InP waste you should collect the waste due to it is Carcinogenic. If it contains H2O2 use empty H2O2 bottles (since they should have a special lid that avoid over pressure). | |||
Remember to mark the bottle that it contains GaAs and InP and that it is carcinogenic.''' | |||
[[Image:FH07.jpg|300x300px|right|thumb|'Fume hood 07' in cleanroom D3]] | [[Image:FH07.jpg|300x300px|right|thumb|'Fume hood 07' in cleanroom D3]] | ||
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When etching InP substrates, both 2” wafers and small pieces, you should collect the used chemicals in a waste bottle. This does not apply for etching epilayers. | When etching InP substrates, both 2” wafers and small pieces, you should collect the used chemicals in a waste bottle. This does not apply for etching epilayers. | ||
There should be a bottle in the fumehood for HCl used to etch InP substrates. | There should be a bottle in the fumehood for HCl used to etch InP substrates marked InP carcinogenic. | ||
Once the bottle is full, it should be brought to the basement of building 346 and a new one placed in the CR. For InP waste a clean and empty developer bottle can be used. | Once the bottle is full, it should be brought to the basement of building 346 and a new one placed in the CR. For InP waste a clean and empty developer bottle can be used. | ||
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When etching GaAs substrates, both 2” wafers and small pieces, you should collect the used chemicals in a waste bottle. This does not apply for etching epilayers. | When etching GaAs substrates, both 2” wafers and small pieces, you should collect the used chemicals in a waste bottle. This does not apply for etching epilayers. | ||
There should be a bottle in the fumehood for citric acid: H2O2 or H2SO4 (10%):H2O2 used to etch GaAs substrates. | There should be a bottle in the fumehood for citric acid: H2O2 or H2SO4 (10%):H2O2 used to etch GaAs substrates marked GaAs carcinogenic. | ||
Once the bottle is full, it should be brought to the basement of building 346 and a new one placed in the CR. '''For the GaAs waste you should use empty H2O2 bottles (since they should have a special lid that avoid over pressure).''' | Once the bottle is full, it should be brought to the basement of building 346 and a new one placed in the CR. '''For the GaAs waste you should use empty H2O2 bottles (since they should have a special lid that avoid over pressure).''' | ||
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C<sub>6</sub>H<sub>8</sub>O<sub>7</sub>:H<sub>2</sub>O<sub>2</sub> is a selective etch of GaAs; does not etch Al<sub>x</sub>Ga<sub>{1-x}</sub>As if x > 0.45. | C<sub>6</sub>H<sub>8</sub>O<sub>7</sub>:H<sub>2</sub>O<sub>2</sub> is a selective etch of GaAs; does not etch Al<sub>x</sub>Ga<sub>{1-x}</sub>As if x > 0.45. | ||
Solid C<sub>6</sub>H<sub>8</sub>O<sub>7</sub> is mixed 1:1 by weight with H<sub>2</sub>O | Solid C<sub>6</sub>H<sub>8</sub>O<sub>7</sub> is mixed 1:1 by weight with H<sub>2</sub>O using magnetic stirring. The solution C<sub>6</sub>H<sub>8</sub>O<sub>7</sub>:H<sub>2</sub>O is thereafter mixed 4:1 volume ratio with H<sub>2</sub>O<sub>2</sub>(30%). | ||
The above C<sub>6</sub>H<sub>8</sub>O<sub>7</sub>:H<sub>2</sub>O<sub>2</sub> solution has an etch-rate of ~360 nm/min in GaAs and < 0.5 nm/min in AlAs @ 25 degC. | The above C<sub>6</sub>H<sub>8</sub>O<sub>7</sub>:H<sub>2</sub>O<sub>2</sub> solution has an etch-rate of ~360 nm/min in GaAs and < 0.5 nm/min in AlAs @ 25 degC. | ||