Vintage Synth Explorer Forums

I've wondered alot how they can cram analog electronics inside an IC chip like the SEM or CEM and Curtis chips that are VCO,VCF,VCA all in one. Do they build transistors and resistors on the molecular level to do that? I know the chips are not digital.

I mean, all those filter chips sound different, so there must be a big amount of components inside each. But they're so small!