A team of researchers at Peking University claimed to have made a breakthrough in chip technology, potentially reshaping the semiconductor race.

Their newly developed 2D transistor is said to be 40% faster than the latest three-nanometre silicon chips from Intel and TSMC while consuming 10% less energy. This innovation, they said, could allow China to bypass the challenges of silicon-based chip making entirely.

“It is the fastest, most efficient transistor ever,” according to an official statement published recently on the PKU website.

Led by physical chemistry professor Peng Hailin, the research team believes their approach represents a fundamental shift in semiconductor technology. 

“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,’” Prof Peng said in the statement.

Overcoming semiconductor barriers

The Chinese team’s breakthrough revolves around a bismuth-based transistor that outperforms the most advanced commercial chips from Intel, TSMC, Samsung, and Belgium’s Interuniversity Microelectronics Centre.

Unlike traditional silicon-based transistors, which struggle with miniaturisation and power efficiency at extremely small scales, this new design offers a solution without those constraints.

According to Prof Peng, while US-led sanctions have restricted China’s access to the most advanced silicon-based transistors, the limitations have also driven Chinese researchers to explore alternative solutions.

“While this path is born out of necessity due to current sanctions, it also forces researchers to find solutions from fresh perspectives,” he added.

The study describes how the team developed a gate-all-around field-effect transistor (GAAFET) using bismuth-based materials. This design is a significant departure from the Fin Field-Effect Transistor (FinFET) structure, which has been the industry standard since Intel commercialised it in 2011. 

A new era for chip technology

The limitations of silicon-based chips have become increasingly evident as the industry attempts to push integration density beyond three nanometres. The new GAAFET structure eliminates the need for the 'fin' used in FinFET designs, increasing the contact area between the gate and the channel.

The researchers compared this change to swapping tall buildings for connected bridges, making it easier for electrons to move, as reported by the South China Morning Post.

To further optimise performance, the researchers turned to 2D semiconductor materials. These materials have a uniform atomic thickness and higher mobility compared to silicon, making them a viable alternative for next-generation chips. However, past attempts to use 2D materials in transistors faced structural challenges that limited their effectiveness.

The PKU team overcame these obstacles by engineering their own bismuth-based materials, specifically Bi2O2Se and Bi2SeO5, which serve as the semiconductor and high-dielectric oxide material, respectively. The high dielectric constant of these materials reduces energy loss, minimises voltage requirements, and enhances computing power while cutting energy consumption.

The researchers fabricated their experimental transistors using PKU’s high-precision processing platform.

The results were validated using density functional theory (DFT) calculations, which confirmed that the Bi2O2Se/Bi2SeO5 material interface had fewer defects and smoother electron flow than existing semiconductor-oxide interfaces.

Allowing electrons to flow with almost no resistance

“This reduces electron scattering and current loss, allowing electrons to flow with almost no resistance, akin to water moving through a smooth pipe,” said Prof Peng.

With transistors based on this technology capable of running 1.4 times faster than the most advanced silicon-based chips at 90% of their energy consumption, the PKU team is now working on scaling up production. They have already built small logic units using the new transistors, demonstrating high voltage gain at ultra-low operating voltages. 

“This work demonstrates that 2D GAAFETs do exhibit comparable performance and energy efficiency to commercial silicon-based transistors, making them a promising candidate for the next technology node,” Prof Peng wrote in the research paper. 

The study was published in the journal Nature Materials.