Formation of Q-carbon with wafer scale integration

We describe the formation of highly uniform Quenched-carbon (Q-carbon) layers by plasma-enhanced chemical vapor deposition (PECVD) followed by low-energy Ar+ ion bombardment to achieve wafer-scale integration of Q-carbon films. After PECVD, 9 nm and 20 nm thick silicon-doped diamond-like carbon (Si-DLC) films showed complete conversion into Q-carbon using 250eV Ar+ ions via negative biasing. However, this conversion was only partial for 30 nm thick films. Detailed EELS, XPS, Raman, and EDS studies were carried out to confirm the formation of Q-carbon by this method. We discuss the mechanism of Q-carbon formation as a result of low-energy ion bombardment during PECVD of thin films. These ions during negative biasing are energetic enough to create Frenkel defects, which support the conversion of the three-fold coordinated sp(2) carbon units in as-deposited carbon into sp(3) bonded five-atom tetrahedron units in Q-carbon. This process enhances the atomic number density and fraction of sp(3) bonded carbon. These diamond tetrahedra are randomly packed and provide easy nucleation sites for diamond. If the underlying substrate can provide an epitaxial template for diamond growth via domain matching epitaxy, then wafer-scale growth of diamond epitaxial films can be achieved for wafer-scale integration and next-generation novel device manufacturing from diamond-related materials.

Automated summary

In this study, highly uniform Q-carbon layers were formed through PECVD and ion bombardment, enabling wafer-scale integration. The conversion of Si-DLC films into Q-carbon was achieved by low-energy ion bombardment, resulting in the formation of diamond nucleation sites. If an epitaxial template is provided by the underlying substrate, wafer-scale growth of diamond epitaxial films can be realized.