A flat transistor comeback?

After years of doping, straining, shrinking, and tweaking, engineers seem to have exhausted all their strategies for improving the planar complementary metal-oxide semiconductor (CMOS) transistors at the heart of today??s computer processors. Producers of cutting-edge chips are now resorting to new structures?? building up in three dimensions or constructing transistors in ultrathin layers of silicon??to ensure that devices keep shrinking and that Moore´s Law keeps going just a bit longer.