Intel's technology and manufacturing group leader, William Holt, says that if Intel wants to keep improving its chips, it will soon have to start using fundamentally new technologies. The company does not know which technology will be adopted, but there are two possible candidates at this stage - Spintronics, and tunneling transistors.
William says that the new technologies will have to be commercialized in four to five years (when Intel moves over to 7-nm production, which is thought to be the limit of silicon transistors), and will initially be used alongside silicon transistors. Intel says we'll need to stop expecting chips to be faster - as the new technologies will mostly benefit the energy efficiency rather than the speed of Intel's future chips.