With the emergence of encapsulation technology, the ultra-thin semiconductor is now a reality.
FREMONT, CA: Ever since the dawn of the semiconductor era, researchers are trying to limit the size of the semiconductors. As electronics get more compact, researchers are eyeing tiny components that can operate reliably in narrow configurations. Promising compounds that are currently gaining traction include gallium selenide (GaSe) and indium selenide (InSe). The compounds can contribute to the formation of ultra-thin layers giving rise to two-dimensional (2-D) semiconductors. The usage of these compounds was limited in the past as they started to degrade as soon as they came in contact with air during manufacturing. However, a new encapsulation technique enables the sensitive material to be incorporated into electrical components without altering their primary properties.
The encapsulated transistors based out of gallium and indium selenide protect the sensitive layers from the external environment and contributes to the performance of the semiconductor. Hexagonal boron nitride (hBN) is the preferred compound for encapsulation as it does not respond to the environmental stimulus. Gallium and Indium are considered as promising elements for several applications like optoelectronics, high-frequency electronics, and sensor technology. Such elements can be used to make flame-like films that are just five to ten atomic layers thick, thereby accounting for a 2-dimensional structure.
Manufacturers leverage lithography-free approach for semiconductor encapsulation. The conventional evaporation deposition using a photomask is unsuitable as the sensitive materials come into contact with air as well as chemicals and thus degrade. Alternatively, the lithography-free approach involves metal electrodes comprising of gold and palladium embedded in hBN foil. Thus, the encapsulation, as well as the electrical contact with the 2-D layer, can be achieved simultaneously. According to the experiments, the total hBN encapsulation protects the 2-D layers from degradation and decomposition, thereby ensuring long-term stability and quality.
The new two-dimensional semiconductors are affordable, and their ultra-thin width makes them suitable for a wide range of industrial applications.