In this letter, I will discuss the evolution of silicon very large scale integration (VLSI) as described by Moore's Law and how and when nanotechnology is likely to impact it. The evolution will be in three phases. In the first, there will be an increasing number of nanotechnologies that will allow conventional complementary metal-oxide semiconductors (CMOS) to continue to scale. In the second phase, nanotechnology will allow unconventional CMOS devices to be introduced. In the final phase, a true, new nanodevice will replace the CMOS transistor. © 2005 Lucent Technologies Inc.