A novel chip-building technique enables seamless vertical stacking of electronic components, potentially revolutionizing AI hardware design and computational power.
MIT engineers have developed a breakthrough method for creating multilayered computer chips that stack transistors vertically without requiring traditional silicon wafer substrates. This innovation could transform how processors are built, enabling more powerful and efficient computing devices while circumventing the physical limitations of conventional two-dimensional chip design.
Published in Nature | Estimated reading time: 4 minutes
The researchers developed a method to grow high-quality semiconducting materials directly on top of each other at temperatures low enough to preserve the underlying circuitry. This achievement addresses a fundamental challenge in chip design: how to continue increasing computational power as traditional methods of shrinking transistors reach their physical limits.
“This breakthrough opens up enormous potential for the semiconductor industry, allowing chips to be stacked without traditional limitations,” says study author Jeehwan Kim, associate professor of mechanical engineering at MIT. “This could lead to orders-of-magnitude improvements in computing power for applications in AI, logic, and memory.”
The innovation centers on a technique for growing transition-metal dichalcogenides (TMDs), a type of two-dimensional material that can maintain its semiconducting properties even at atomic scales. Unlike previous attempts that required high temperatures that would damage underlying circuits, the team achieved success at just 380 degrees Celsius – cool enough to preserve the chip’s functionality.
Drawing inspiration from metallurgy, the researchers found that growing these materials from the edges of specially designed pockets required less energy and heat than traditional methods. This insight led to the development of a process where single-crystalline materials could be grown directly on top of existing circuitry.
The team demonstrated the practical application of their technique by creating a multilayered chip with alternating layers of two different TMDs: molybdenum disulfide and tungsten diselenide. These materials serve as the building blocks for n-type and p-type transistors respectively, essential components for logic operations in computing.
The implications of this advancement extend beyond just making chips more compact. Without thick silicon wafers between layers, the semiconducting elements can communicate more directly, leading to faster and more efficient computation. This could enable AI hardware in laptops or wearable devices to match the processing power of today’s supercomputers while consuming less energy.
To move this technology toward commercial applications, Kim has launched a company called FS2 (Future Semiconductor 2D materials). The next phase of development will focus on scaling up the technology to demonstrate professional AI chip operation.
Glossary
- Transition-Metal Dichalcogenides (TMDs)
- Two-dimensional materials that can maintain semiconducting properties at extremely small scales
- Single-Crystalline Material
- A material whose crystal lattice is continuous and unbroken throughout its entire structure
- Monolithic 3D Integration
- A technique for building three-dimensional electronic components as a single, seamless structure
Test Your Knowledge
What maximum temperature must the new growth process stay below to prevent damage to underlying circuitry?
The process must stay below 400 degrees Celsius to preserve the underlying circuitry.
What type of materials did the researchers use to create the stacked transistors?
The researchers used transition-metal dichalcogenides (TMDs), specifically molybdenum disulfide and tungsten diselenide.
How does the new stacking method improve upon conventional 3D chip designs?
The new method eliminates the need for silicon wafers between layers and allows direct growth of semiconducting materials on top of each other, enabling better communication between layers.
What metallurgical principle did the researchers apply to achieve lower-temperature growth of single-crystalline materials?
They utilized the principle that nucleation occurs more readily at the edges of a mold, requiring less energy and heat than center nucleation.
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