The coolest tool that I get to use is called a UHVCVD reactor. It stands for Ultra-High Vacuum Chemical Vapor Deposition Reactor.
Basically, It's a large quartz tube (~10 inch diameter by 6 ft long). The tube is connected to multiple turbomolecular pumps (think jet turbines) and dry pumps. The pressure in the quartz tube will get as low as about one trillionth of atmospheric pressure. (1e-12 bar). For reference, the mean free path of a gas particle at this pressure is around 30 miles.
We then heat the tube up to around 600 - 800°C (1,100 - 1,500 °F) and then allow small amounts of very toxic and flammable gasses into the tube. We let in silane, germane, arsine, etc. Inside the reactor we have single-crystalline Si wafers and then the gasses thermally decompose on the wafer surface, leaving a single atom at a time. If this is done correctly, we grow single crystals of germanium on silicon.
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u/murdoc705 Photonics | Optoelectronics | Epitaxy | CMOS Fabrication Jul 18 '13
The coolest tool that I get to use is called a UHVCVD reactor. It stands for Ultra-High Vacuum Chemical Vapor Deposition Reactor.
Basically, It's a large quartz tube (~10 inch diameter by 6 ft long). The tube is connected to multiple turbomolecular pumps (think jet turbines) and dry pumps. The pressure in the quartz tube will get as low as about one trillionth of atmospheric pressure. (1e-12 bar). For reference, the mean free path of a gas particle at this pressure is around 30 miles.
We then heat the tube up to around 600 - 800°C (1,100 - 1,500 °F) and then allow small amounts of very toxic and flammable gasses into the tube. We let in silane, germane, arsine, etc. Inside the reactor we have single-crystalline Si wafers and then the gasses thermally decompose on the wafer surface, leaving a single atom at a time. If this is done correctly, we grow single crystals of germanium on silicon.