As chipmakers continue to shrink the size of their products, they are facing the limits of how much computing power can be crammed into a single chip. A record-breaking chip cleverly circumvents this problem, potentially leading to more sustainable manufacturing of electronic devices.

Since the 1960s, the key to improving the performance of electronic products has been to make their basic building blocks, transistors, smaller and more densely integrated onto chips. This trend is summarized by the famous Moore's Law, which states that the number of components on a microchip doubles every year. However, this trend began to "decline" around 2010. Xiaohang Li and his colleagues at King Abdullah University of Science and Technology in Saudi Arabia now show that the solution may not be to make chips smaller, but rather to stack them up.

They designed a different type of semiconductor chip with 41 vertically stacked layers, separated by insulating material. This transistor stack is approximately 10 times taller than previously manufactured chips. To test its functionality, the team created 600 chips with similar performance and reliable operation, and used some of these stacked chips to implement basic operations required for computers or sensing devices. The performance of these stacked chips was comparable to some conventional, unstacked chips.

Li stated that manufacturing these stacked layers requires significantly less energy than traditional chip manufacturing methods. Thomas Anthopoulos, a team member from the University of Manchester in the UK, said that this new chip may not necessarily lead to new supercomputers, but if it can be used in common devices such as smart home appliances and wearable health devices, it could reduce the carbon footprint of the electronics industry, while each additional layer provides more functionality.

How tall can the chip "grow"? "There really is no limit. We can keep doing it, it just requires more effort," Anthopoulos said.

Muhammad Alam of Purdue University stated that the upper temperature limit a chip can withstand before malfunctioning remains an engineering challenge. He described it as akin to wearing several down jackets while trying to stay cool, as each additional layer adds heat. Alam believes the current upper temperature limit for chips should be increased by 30°C or more from 50°C to enable practical applications outside the laboratory. However, in his view, this "vertical development" approach is the only way for electronic devices to advance in the short term.