In recent times, there has been a boom in new artificial intelligence (AI) applications such as ChatGPT. These chatbots that generate natural human language require denser and more powerful computer chips. However, semiconductor chips are traditionally made with bulk materials, which are 3D structures. Hence, stacking multiple layers of transistors to create denser integrations is very difficult.
To address this issue, researchers at the Massachusetts Institute of Technology (MIT) have demonstrated a novel technology that can effectively and efficiently “grow” layers of 2D transition metal dichalcogenide (TMD) materials on top of a fully fabricated silicon chip to enable denser integrations, a news release from MIT explains.
Growing 2D materials directly on a silicon chip is challenging because the process usually requires temperatures of about 600 degrees Celsius, while silicon transistors and circuits could break down when heated above 400 degrees. MIT researchers have developed a process of growing them at low temperatures that do not cause damage to the chip and allow 2D semiconductor transistors to be directly integrated, according to the press statement. The paper was published in the journal Nature Nanotechnology.
“Using 2D materials is a powerful way to increase the density of an integrated circuit. What we are doing is like constructing a multistory building. If you have only one floor, which is the conventional case, it won’t hold many people. But with more floors, the building will hold more people that can enable amazing new things. Thanks to the heterogeneous integration we are working on, we have silicon as the first floor and then we can have many floors of 2D materials directly integrated on top,” Jiadi Zhu, an electrical engineering and computer science graduate student and co-lead author of a paper on this new technique, said in the news release.
The new technology can also significantly reduce the time needed to grow the 2D materials. It can grow a uniform layer of TMD material in less than an hour over entire 8-inch wafers. This has also helped the researchers to successfully integrate a 2D material layer onto much larger surfaces. These advantages make this novel method well-suited for use in commercial applications, according to the news release.
The researchers now aim to enhance this technique to explore how the low-temperature growth process can be used for surfaces such as polymers, textiles, or even papers. This could enable the integration of semiconductors with everyday objects such as clothing or notebooks.