Intel's successor to the current 'Conroe' and 'Allendale' based Core 2 Duo processors, dubbed 'Penryn', is still a ways away. While Intel hasn't disclosed everything, it has been known that it will be produced on a 45nm process. Hexus gives some of the low-down: Now cast your eyes to the bit atop the silicon. The first, thin layer is a Silicon Oxide layer; it's an insulator. Next we have a polysilicon gate, comprising the same type of silicon as the source/drain regions. Above that we have a layer of something with a low resistance. These three parts form the 'gate' of the transistor. If a voltage is applied here, an electromagnetic field creates a 'channel' within the silicon substrate that allows electrons to flow from source to drain (and so allows current to flow the other way, as we perceive it). Increase the voltage at the gate and more current can flow; if the gate voltage isn't high enough, then the field will be weakened and the channel will be saturated, causing current to be restricted. Additional coverage can be found at: Anandtech Hot Hardware PC Perspective
