Abstract :
Ever since the integrated circuit made its debut, semiconductors have been "single-story" affairs. But chipmakers are now considering ways to build additional transistor-packed layers right on top of the first. The approach–dubbed monolithic, or sequential, fabrication–could boost the density, efficiency, and performance of logic chips without necessitating a move to smaller transistors. And that could be a boon for an industry that is seriously contemplating the end of miniaturization.
