Antenna Rules
Antenna rules are normally expressed as an allowable ratio of metal area to gate area. There is one such ratio for each interconnect layer. The area that is counted may be more than one polygon —it is the total area of all metal connected to gates without being connected to a source/drain implant.
- If the process supports different gate oxides, such as a thick oxide for higher voltages and a thin oxide for high performance, then each oxide will have different rules.
- There are cumulative rules, where the sum (or partial sum) of the ratios over all interconnect layers sets the limit.
- There are rules that consider the periphery of each polygon, as well.
Before signing-off a physical design/layout for fabrication, the Antenna Rule Check is therefore performed.
Read more about this topic: Antenna Effect
Famous quotes containing the word rules:
“Rules and particular inferences alike are justified by being brought into agreement with each other. A rule is amended if it yields an inference we are unwilling to accept; an inference is rejected if it violates a rule we are unwilling to amend. The process of justification is the delicate one of making mutual adjustments between rules and accepted inferences; and in the agreement achieved lies the only justification needed for either.”
—Nelson Goodman (b. 1906)