Growth of single-walled carbon nanotubes using germanium nanocrystals formed by implantation

This paper presents a complementary metal oxide semiconductor compatible method for the chemical vapor deposition of single-walled carbon nanotubes (SWNTs). The method uses Ge implantation into a SiO₂ layer to create Ge nanocrystals, which are then used to produce SWNTs. The results of atomic force microscopy and scanning electron microscopy analyses indicate that Ge implantation provides good control of particle size and delivers a well-controlled SWNT growth process. The SWNT area density of 4.1±1.2 μm in length/μ m² obtained from the Ge nanocrystals is comparable to that obtained from metal-catalyst-based methods used to fabricate SWNT field-effect transistors. A carbon implantation after Ge nanocrystal formation significantly enhances the process operating window for the growth of the SWNTs and increases the area density.