Most electronic equipment and devices are still using silicon semiconductors as it is difficult to fabricate highly purified and densely packed semiconductors with carbon nanotubes(CNTs). A research team from the School of Electrical Engineering at the Korea Advanced Institute of Science and Technology (KAIST) led by Professor Yang-Kyu Choi, in collaboration with Professor Sung-Jin Choi of Kookmin University, is set to change that.

CNT semiconductor fig1 (cr) Figure 1: 3D rendering of the CNT Electronic Device and its Scanning Electron Microscope (SEM) image.  

The scientists have developed a semiconductor that features high-current density with a width less than 50μm. They used a 3D fin-gate to vapour-deposit CNTs on its top. The 3D fin structure enabled them to pack 600 CNTs/μm. This structure can have 20 times more nanotubes than a 2D structure, which can only vapour-deposit 30 in the same 1μm width.

CNT-based semiconductors are expected to be five times faster than silicon-based devices and will require five times less power during operation. In addition, the research team has used semi-conductive CNTs having a purity rating higher than 99.9% from a previous study to obtain a high yield semiconductor.

CNT semiconductor fig2 (cr) Figure 2: 3D transistor device on an 8-inch base and the SEM image of its cross section.  

Furthermore, the new semiconductor can be made by or will be compatible with the equipment for producing silicon-based semiconductors, so there will be no additional costs.

Researcher Lee said, “As a next-generation semiconductor, the carbon nanotube semiconductor will have better performance, and its effectiveness will be higher. Hopefully, the new semiconductor will replace the silicon-based semiconductors in ten years.”

Dong Il Lee, a postdoctoral researcher at KAIST’s Electrical Engineering School, first authored this study entitled “Three-Dimensional Fin-Structured Semiconducting Carbon Nanotube Network Transistor.”