Stacked single-crystalline field-effect transistors

Abstract

The researchers — who are based at the Massachusetts Institute of Technology, the Samsung Advanced Institute of Technology, Sungkyunkwan University and the University of Texas at Dallas — show that confined selective growth of transition metal dichalcogenides can be used to integrate n-type field-effect transistors based on molybdenum disulfide on top of p-type field-effect transistor arrays based on tungsten diselenide at 385 °C. Nucleation events occur at the edges and corners of areas that are geometrically confined using silicon dioxide growth masks on amorphous hafnium oxide surfaces. The distribution and size of the trenches ensures only a single nucleation event occurs per trench, which leads to a single-crystalline domain.

The team fabricated 32 vertical two-dimensional-material-based complementary metal–oxide–semiconductor (CMOS) devices at a yield of around 94% and showed that the approach can be used to create operational inverters, as well as NAND and NOR gates.