Rapid thermal process by RF heating of nano-graphene layer/silicon substrate structure: Heat explosion theory approach

Introduction: There are a number of investigations devoted to the induction heating (IH) of a conductor film/a silicon substrate structure in a radio-frequency (RF) magnetic field perpendicular to the substrate surface... [ view full abstract ]

Introduction: There are a number of investigations devoted to the induction heating (IH) of a conductor film/a silicon substrate structure in a radio-frequency (RF) magnetic field perpendicular to the substrate surface [1-2].  The heat explosion theory approach was used to describe the heating process. Results of the theory were successfully proved in the experiments with Ti and Ta-Ti-Si thin films deposited on Si (111) and Si (100) substrates [1-2]. One drawback of using these systems is pollution of silicon substrates due to the fast diffusion of metallic impurities.

Methods: A new rapid thermal process (RTP) is proposed which is based on IH of a nano-graphene layer deposited on back side of a silicon substrate in a RF magnetic field perpendicular to the layer surface. The characteristic property of the method is that no additional susceptor is required, despite the fact that thickness of the graphene layer/Si substrate structure is less than a skin depth. In contrast to metals, the diffusion of carbon in silicone is very slow. The novel RTP can be successfully applied in technological processes of fabrication of films and layers on silicon substrates as well as to study graphene transformations. 

Results and Discussion: The heating kinetics is analyzed as a function of graphene layer thickness, sheet resistance of the graphene layer, specimen dimensions, thermal parameters, as well as the amplitude and frequency of the applied RF magnetic field. It is shown that two regimes of the heating can be realized. The first one is characterized by heating of the structure up to a finite temperature determined by equilibrium between dissipated power loss due to eddy-currents and heat transfer to environment. The second regime corresponds to a fast unlimited temperature increase (heat explosion). The criterion of realization of the regimes is obtained in analytical form. Based on this criterion, it is shown the possibility of the heat explosion regime for graphene layer/silicon substrate structure.

1. J. Pelleg, S. Rosenberg, and M. Sinder, Acta Mater., Vol. 59, 4283–4290, 2011.

2. M. Sinder, J. Pelleg, V. Meerovich, and V. Sokolovsky, PIERS Proceedings, Stockholm, Sweden, Aug. 12–15, 1292-1296, 2013.