Researchers in China say they have created a new silicon-free transistor that could significantly boost performance while reducing energy consumption. The team says this development represents a new direction for transistor research.
The scientists said that the new transistor could be integrated into chips that could one day perform up to 40% faster than the best existing silicon processors made by U.S. companies like Intel. This is according to a report in the South China Morning Post (SCMP).
Despite that dramatic increase in power, the researchers claim that such chips would also draw 10% less power. The scientists outlined their findings in a new study published Feb. 13 in the journal Nature.
Lead author of the study Hailin Peng, professor of chemistry at Peking University (PKU) in China, told SCMP: “If chip innovations based on existing materials are considered a ‘short cut’, then our development of 2D material-based transistors is akin to ‘changing lanes’.”
A new kind of silicon-free transistor
The efficiency and performance gains are possible thanks to the chip’s unique architecture, the scientists said in the paper, specifically the new two-dimensional silicon-free transistor they created. This transistor is a gate-all-around field-effect transistor (GAAFET). Unlike previous leading transistor designs like the fin field-effect transistor (FinFET), a GAAFET transistor wraps sources with a gate on all four sides, instead of just three.
At its most basic level, a transistor is a semiconductor device found in every computer chip. Each transistor has a source, a gate and a drain, which allow the transistor to function as a switch.
The gate is how a transistor controls the flow of current between the source and drain terminals and can act as both a switch and amplifier. Wrapping this gate around all sides of a source (or sources, as some transistors contain multiple) — instead of just three as in conventional transistors — leads to potential improvements in both performance and efficiency.
This is because a fully wrapped source provides better electrostatic control (as there is less energy loss to static electricity discharges) and the potential for higher drive currents and faster switching times.
While the GAAFET architecture isn’t itself new, the PKU team’s use of bismuth oxyselenide as the semiconductor was, as well as the fact they used it to create an “atomically-thin” two-dimensional transistor.
2D bismuth transistors are less brittle and more flexible than traditional silicon, the scientists added in the study. Bismuth provides better carrier mobility —the speed at which electrons can move through it when an electrical field is applied. It also has a high dielectric constant — a measure of a material’s ability to store electrical energy — which contributes to the transistor’s increased efficiency.
Should this transistor be fitted into a chip that does prove faster than US-made chips by Intel and other companies, it could also allow China to sidestep current restrictions on buying advanced chips and tap into US chip-making by shifting to a wholly different manufacturing process.
