The evolution of scaling from the homogeneous era to the heterogeneous era

Traditional MOSFET scaling served our industry well for more than three decades by providing continuous improvements in transistor performance, power and cost. This was the era of homogeneous scaling where similar materials and device structures were scaled from generation to generation and served a wide range of integrated circuits from memory to logic applications. Traditional scaling ran out of steam in the early 2000s due mainly to the inability to further scale the SiO₂ gate oxide and this ushered in the beginning of the heterogeneous era where new materials and new device structures are being continually introduced to deliver the expected benefits of scaling. Going forward, an ever wider range of device types will be needed and the challenge we face is how to identify, develop and manufacture these revolutionary devices, and also how to integrate heterogeneous devices into compelling products.