https://en.wikipedia.org/wiki/Multigate_device#Tri-gate_.283D.29_transistor https://en.wikipedia.org/wiki/Multigate_device#Tri-gate_.283... But you're right, a

https://en.wikipedia.org/wiki/Multigate_device#Tri-gate_.283D.29_transistor https://en.wikipedia.org/wiki/Multigate_device#Tri-gate_.283... But you're right, actual stacked chips ("3D" ICs) aren't used much, largely for thermal management reasons.