Intel today outlined its plan to build the millions of transistors that make up its microprocessors using high-k dielectric materials.
The move won't take place until 2007, when the chip colossus shifts down to a 45nm fabrication process, but when it does, it will reduce the amount of current leaking out of each transistor by a factor of 100 - significantly reducing each chip's power consumption, the company believes.
Today's processors use silicon dioxide as the gate insulator or dielectric. The gate controls the flow of electrons from one side of the transistor to the other, and is what allows the component to operate as a switch. As the gate gets thinner - a result of shrinking chip fabrication processes - more current leaks out through the dielectric, requiring chip designers to use a higher voltage to switch the transistor on efficiently. High-k material reduces that current leakage, allowing transistors to operate at a lower voltage. The result is less power consumed and less power dissipated as heat.
Leakage is increasingly a problem for next and future generations of processors. One of the reasons Intel's upcoming 'Prescott' Pentium 4 processor consumes 90-100W - more than today's P4s - despite being fabbed at a smaller size is a result of the greater amount of current lost through the chip's smaller transistor gates.
Past efforts to develop high-k dielectrics have foundered on reduced transistor efficiency. Intel appears to have cracked that problem. However, there is still the issue of current leaking out of the transistor gate when the switch is turned off.
"This is the first convincing demonstration that new gate materials will enable transistors to perform better, while overcoming the fundamental limits of the silicon dioxide gate dielectric material that has served the industry for more than three decades," said Sunlin Chou, Intel senior VP and general manager of the Technology and Manufacturing Group.
"Intel will use this advancement along with other innovations, such as strained silicon and tri-gate transistors, to extend transistor scaling and Moore's Law," he added.
Intel isn't saying what substances constitute its high-k dielectric. Nor will it yet identify the new metals it plans to use for the gate electrode. The metals - one for CMOS transistors, the other for PMOS designs - replace today's polysilicon electrode material, which is "not compatible" with the high-k dielectric.
Intel will discuss details of the development of new transistor materials tomorrow at the 2003 International Workshop on Gate Insulator in Tokyo. ®