eli5: How are resistors, capacitors and coils placed on integrated circuits?
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Here are [the examples with pictures](https://www.daenotes.com/electronics/devices-circuits/integrated-components-ic).
Capacitor is quite easy, given that the most widely used integrated transistor (MOSFET) has a capacitor as part of its design. You just use semiconductor as one plate, oxide as insulator, and a metal track as second plate. They also use diodes in reverse polarity (although it is no longer a capacitor, but a varicap)
Resistors is harder. In older times, they used a long track: 3-4 resistors could take 60% of the chip. Nowadays, resistors are made from very depleted semiconductor regions: similar to a base of bipolar transistor.
Inductors are the hardest: all you can do is to print [a spiral metal track](https://miscircuitos.com/an-overview-of-on-chip-inductors-for-integrated-circuits-ic-types-pro-cons/). This creates quite a low quality inductor. Creating an integrated ferromagnetic core is very difficult and expensive, so most integrated inductors have to live without.
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