Topic: Tinier Transistors with Hafnium

[Astronuc]

The Magic Ingredients in Intel's New, Tinier Transistor

Last week Intel and IBM both announced that they had figured out a way to further shrink the size of transistors, the tiny on-off switches that power computers. The trick, according to Intel, is introducing the metal hafnium into the mix—an addition that marks the first major change in transistor materials in four decades. Hafnium-based computer circuits would likely be denser, faster and consume less power than existing microprocessors.

"It's a very, very significant event," says electrical engineer Carlton Osburn of North Carolina State University, member of a research team that studied hafnium and other advanced transistor materials. "This directly addresses one of those grand challenges" in semiconductor manufacturing.

. . . . In its transistors, hafnium oxide plays the role of the so-called gate dielectric, an insulating layer that separates the transistor's electrode from its silicon channel for carrying current. . . .

Over the past decade, Intel and other microchip makers had increasingly bumped up against a fundamental problem: electricity would begin leaking from the glasslike silicon dioxide insulating layer as its width shrank to nearly a nanometer. Consequently, the transistors required inordinate amounts of power.

To overcome this obstacle, chipmakers had to determine how to replace silicon dioxide with so-called high-k materials like hafnium and zirconium. A material's performance as a gate dielectric depends on its thickness and its k-value, or dielectric constant, which reflects its ability to store a charge. Because hafnium has a higher k-value than silicon dioxide, it should be able to do the same or better job at a thickness that prevents leakage. That advance would allow Intel to shrink the smallest dimension of its transistors from today's 65 nanometers to a svelte 45 nanometers, keeping the furious pace of transistor miniaturization on its expected track.

Well the price of Hf just went up.  Hf is produced as a by-product of the production of nuclear grade Zr metal.

The tinier transistors are great for less energy, but exposure to gamma or other ionizing radiation is more problematic.