The semiconductor industry is facing a triple challenge of increasing computing power, shrinking chip sizes, and managing power in densely packed circuits. While silicon remains the dominant material, there is growing interest in two-dimensional (2D) semiconductors, which are extremely thin and offer advantages in terms of control, precision, and energy efficiency.
Silicon has limitations in terms of how thin it can be made due to its three-dimensional nature, which has led researchers to explore 2D materials. These ultra-thin materials have the potential to reduce energy consumption and occupy less surface area on a chip.
However, until recently, creating high-performing 2D semiconductors that can be integrated with silicon chips has proven challenging. Some 2D materials required high deposition temperatures that damaged underlying silicon, while others did not meet performance standards or lacked purity.
Researchers at the University of Pennsylvania School of Engineering and Applied Science have made significant progress by successfully growing a high-performing 2D semiconductor, indium selenide (InSe), on an industrial-scale wafer. Importantly, InSe can be deposited at low temperatures compatible with silicon chips.
The breakthrough was achieved using a growth technique called “vertical metal-organic chemical vapor deposition” (MOCVD). Unlike previous methods that introduced indium and selenium simultaneously, MOCVD introduced indium continuously while pulsing selenium. This approach allowed for the creation of a uniform 50:50 ratio of indium and selenium across the entire wafer, ensuring chemical purity.
