Specific Process Knowledge/Thermal Process/Oxidation: Difference between revisions
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==Oxidation== | ==Oxidation== | ||
At DTU Nanolab we have seven furnaces and one RTP (rapid thermal processors) for thermal oxidation of silicon samples: Boron Drive-in + Pre-dep furnace (A1), Gate Oxide furnace (A2), Phosphorous Drive-in furnace (A3), Anneal-oxide furnace (C1), Anneal-Bond furnace (C3), Al-Anneal furnace ( | At DTU Nanolab we have seven furnaces and one RTP (rapid thermal processors) which can be used for thermal oxidation of silicon samples: Boron Drive-in + Pre-dep furnace (A1), Gate Oxide furnace (A2), Phosphorous Drive-in furnace (A3), Anneal-oxide furnace (C1), Anneal-Bond furnace (C3), Al-Anneal furnace (C4), Oxidation 8" (E1), Resist Pyrolysis furnace and RTP Annealsys. | ||
Thermal oxidation can take place either by a dry process or by a wet process, depending on what furnace that is used for the oxidation. The film quality for a dry oxide is better than the film quality for a wet oxide with regards to density and dielectric constant. However, the oxidation rate is slow for dry oxidation. | Thermal oxidation can take place either by a dry process or by a wet process, depending on what furnace that is used for the oxidation. The film quality for a dry oxide is better than the film quality for a wet oxide with regards to density and dielectric constant. However, the oxidation rate is slow for dry oxidation. | ||
*Dry oxidation is used to grow 5 nm - 300 nm of oxide in the furnaces: A1, A2, A3, C1, C3, C4 and | *Dry oxidation is used to grow 5 nm - 300 nm of oxide in the furnaces: A1, A2, A3, C1, C3, C4, E1 and Resist Pyrolysis furnaces. | ||
*Wet oxidation is used to grow up to 3 µm of oxide in the furnaces: A1, A3, C1 and | *Wet oxidation is used to grow up to ~3 µm of oxide in the furnaces: A1, A3, C1, C3 and E1 furnaces. | ||
Wafers with oxide layers thicker than >3 µm can normally not be made in the cleanroom and will have to be bought (but check the wafer shop first - there might be some on stock). It is NOT allowed to oxidize the same wafers two time to get a thicker layer than 3 µm without approval | Wafers with oxide layers thicker than >3 µm can normally not be made in the cleanroom and will have to be bought from somewhere else (but check the wafer shop first - there might be some on stock). It is NOT allowed to oxidize the same wafers two time to get a thicker layer than 3 µm without approval. | ||
Thermal oxidation can done at temperatures up to 1050 C - 1150 C, depending on the furnace - and especially the diameter of the furnace tube. At these high temperatures, the quartz tube in the | Thermal oxidation can done at temperatures up to 1050 C - 1150 C, depending on the furnace - and especially the diameter of the furnace tube. At these high temperatures, the quartz tube in the furnace might start to deform, so therefore the oxidation times are restricted: | ||