Fun fact about "antennas" in chip manufacturing: They have nothing to do with actual antennas. Charge can build up on long wires during manufacturing because the chemicals involved are not neutral and have some interactions with exposed wires. That charge needs to go somewhere to protect the rest of the circuits. There's nothing RF about this.
Later technologies (28 nm and below) have extensive design rules around prevention of "antenna" effects.
I think that’s incorrect. The article and the Wikipedia page on the antenna effect say antenna effects are caused by plasma etching, which uses RF to create the plasma.
It’s precisely these orthogonal, secondary concerns that make every industry more difficult than people on the outside might think.
Articles like yours shed light on these challenges.
I’m reminded of a recent project working on a (small!) data warehouse where for the first time in my career I had to not only be concerned with theoretical performance of queries, such as the presence or absences of indexes, but orthogonal concerns such as the time taken to rewrite terabytes of data on disk during night ETL jobs… combining with the “change rate” of the source data.
Your article is a similar concern that only specialists in the in the industry are even aware of: it’s not enough to logically route connections — a challenging optimisation all by itself — but there are these competing physical optimisation issues as well that need to be simultaneously optimised!
The antenna diodes are only relevant during manufacturing, when a metal line is connected on one end but not the other. ESD diodes on the other hand protect inputs against electrostatic discharge when the chip is in use.
Later technologies (28 nm and below) have extensive design rules around prevention of "antenna" effects.
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