So where will we turn for future scaling? We will continue to look to the third dimension. We’ve created experimental devices that stack atop each other, delivering logic that is 30 to 50 percent smaller. Crucially, the top and bottom devices are of the two complementary types, NMOS and PMOS, that are the foundation of all the logic circuits of the last several decades. We believe this 3D-stacked complementary metal-oxide semiconductor (CMOS), or CFET (complementary field-effect transistor), will be the key to extending Moore’s Law into the next decade.

The Evolution of the Transistor

Continuous innovation is an essential underpinning of Moore’s Law, but each improvement comes with trade-offs. To understand these trade-offs and how they’re leading us inevitably toward 3D-stacked CMOS, you need a bit of background on transistor operation.

Every metal-oxide-semiconductor field-effect transistor, or MOSFET, has the same set of basic parts: the gate stack, the channel