Agreed that 18A is a truly game changer.
The TEM cross-section looks amazing. It shows how the GAA RibbonFET transistors are built and how PowerVia backside power is delivered.
You can see the gate wraps entirely around the horizontally stacked channels on all sides. Based on this picture, we can say the structure has a superior electrical control and reduced leakage. Also note that the PMOS channel width shrinks to 20โ22 nm and the NMOS is kept at 30โ34 nm. This drastically downsizing components should fit more dies per wafer.
Then the vertical power vias deliver current upward from backside metal to transistors. It looks like the front-side M0 layer is reserved exclusively for signal wiring? If so, it should have the effect of eliminating routing congestion, cutting power loss and enabling higher operating frequencies.
So it looks to me that 18A has compact low-leakage transistors plus freed-up front-side routing space that allow denser chip integration with lower power consumption. Nice job $INTC