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by XorNot
822 days ago
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This is missing one of the most important reasons though: Silicon Oxide. Silicon Oxide is almost perfectly lattice matched to silicon, but completely insulating. Which means it's incredibly easy to grow features onto polished silicon wafers because the oxidation product of the material is exactly what you need in order to build up insulating features - i.e. MOSFET junctions, capacitors and conductive paths. |
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But you are complety right, the oxidation properties of Si are really fortunate and ICs would have taken decades longer if it were not for that. SiO2 is really the unsung hero of the silicon age.
- SiO2 has a high bandgap and a very good insulator.
- It is quite inert to many chemical and gasses. (e.g. germanium oxide is soluble in water, which is a headache)
- It can easily be grown on stoiciometric form by oxidizing silicon and will form an abrupt interface to Si.
- The formation proceeds by diffusion of oxygen to the Si interface. This is in contrast to other metal oxides, where the metal will diffuse to the surface and create a nonstoiciometric mixture.
There is no other semiconductor that forms as good an oxide. Very few metals form insulating oxides on their surface, one notable exception is Aluminum.
Edit: The famous paper that describes the SiO2 formation kinetics was actually co-authored by Andy Grove, from intel CEO fame.
https://en.wikipedia.org/wiki/Deal%E2%80%93Grove_model