Formation of silicon-on-diamond by direct bonding of plasma-synthesized diamond-like carbon to silicon

Abstract

We propose to replace the buried SiO2 layer in silicon-on-insulator with a plasma synthesized diamond-like-carbon (DLC) thin film to mitigate the self-heating effects. The DLC films synthesized on silicon by a plasma immersion ion implantation & deposition process exhibit outstanding surface topography, and excellent insulating properties are maintained up to an annealing temperature of 900°C. Hence, the degree of graphitization in our DLC materials is insignificant during thin-film transistor processing and even in most annealing steps in conventional complementary metal oxide silicon processing. Using Si∕DLC direct bonding and the hydrogen-induced layer transfer method, a silicon-on-diamond structure has been fabricated. Cross-sectional high-resolution transmission electron microscopy reveals that the bonded interface is abrupt and the top Si layer exhibits nearly perfect single crystalline quality. A model is postulated to describe the reactions occurring at the interface during the annealing steps in Si-DLC wafer bonding.