Transistors Only Three Atoms Thick? Cornell Researchers "Eureka!" Captured in Nature Journal
Three atoms thick. According to a paper published this week in the science journal Nature
by a group of researchers from Cornell University, that is the breadth of the transistors
that can now be produced using an experimental — and highly conductive — material called transition metal dichalcogenide (also called a TMD). We aren't talking five atoms thick, or even four (because any schmoe with a hobbyist chemistry set can do that), but transistors rendered at a thickness of just three atoms.
As it applies to theoretical science
and human achievement, the harnessing of TMD for practical use is quite remarkable. It is the prospective leaps that could potentially be made in technological hardware and gadgetry as a result, though, that may some day — and perhaps some day soon — pique the excitement of the masses.
Lending continuing credence to Moore's Law
, which states that the number of transistors per square inch of integrated circuitry should double every year, TMD is causing quite a stir in physics and manufacturing circles alike due to its remarkable thinness. Occurring as films that span mere atoms, TMD can be used in the construction of solar
cells, light detectors, and semi-conductors
. Naturally, the material is quite difficult to work with in these early days, however, the development reported in Nature
is a sure indicator that silicon's position as the transistor material of choice is far from assured.
The group achieved a 99% success rate, producing 200 transistors from TMD with 198 able to conduct electricity. The Nature
article describes how they were able to arrive at their results in mass producing the transistors through the application of a metal organic chemical vapour deposition (MOCVD) technique, which starts with two commercially available precursor compounds — diethylsulfide and a metal hexacarbonyl compound. The TMD transistors were grown with a mix of the two compounds, baked in the presence of hydrogen gas on silicon wafers for 26 hours and at a temperature of 550 Celsius. And although the production factors represent hurdles with regard to commercial manufacturing — many auxiliary materials will combust at 550 C° — the results are nonetheless considered to be a significant step forward.
“Existing growth methods for large-scale monolayer TMDs have so far produced materials with limited spatial uniformity and electrical performance,” the researchers write. “Our work is a step towards the realization of atomically thin integrated circuitry.”
TMD currently looks to be among the most promising silicon
alternatives. Another material cited for its potential to push beyond tried-and-true silicon is graphene
, a one-atomic thick carbon material, however, the material lacks a bandgap — a necessary quality of transistor material — and thus its use in commercial transistor production is currently considered conjectural at best.