I looked at a random 7400-series die and I think the feature size is about 5 µm. (The width of the thinnest metal and silicon features.) Bipolar chips have diff

I looked at a random 7400-series die and I think the feature size is about 5 µm. (The width of the thinnest metal and silicon features.) Bipolar chips have different construction from a MOS processor, so the features aren't directly comparable, but this should give you a rough idea.