Current-Induced Complementary Doping to Graphene from Hydrogen Silsesquioxane Passivation Layer

Hydrogen silsesquioxane (HSQ) is a high-resolution negative-tone e-beam resist. Apart from that, it also frequently uses a complementary dopant to 2D materials. So far, most of the studies on an HSQ complementary doping process have been performed by electron beam exposure during the device fabrication. Doping induced by post-treatment after device fabrication has not been investigated. Herein, current annealing is reported as an easy access to induce controlled complementary doping from the capping HSQ to the graphene. Joule heating caused by the current is able to break silicon-hydrogen and silicon-oxygen bonds in HSQ. Subsequently, hydrogen and oxygen atoms generated are trapped at the HSQ-graphene interface, therefore, n-type and p-type doping graphene, respectively. The doping polarity and strength can be controlled by current strength and annealing duration.

Automated summary

The study reports a method for controlled complementary doping by current annealing, which introduces complementary doping from capping HSQ into graphene by trapping generated hydrogen and oxygen atoms at the HSQ-graphene interface, leading to n-type and p-type doping of graphene, respectively.