Growth Mechanism of 2D Mo<sub>2</sub>C on Cu via CVD
Göknur Cambaz Büke, Ömer R. Çaylan, Omer Tarik Ogurtani
Abstract
High Resolution Image Download MS PowerPoint Slide This study investigates the growth of Mo 2 C crystals via chemical vapor deposition (CVD) in the presence of a carbon (H 2 /CH 4 gas)-containing environment. The study employs both theoretical and experimental approaches to investigate the vertical and lateral (in-plane) growth of Mo 2 C crystals. A physico-mathematical consideration is applied to develop an analytical forward model, which incorporates bulk diffusivities, surface diffusivities, and solubility gradients for Mo 2 C crystal growth. Coupled nonlinear flow equations have been advanced for the Mo-, Cu-, Mo 2 C layer framework and effectively predicted the Mo 2 C crystal growth rate for both vertical and lateral directions. Forming the Mo 2 C crystal height and diameter was directly correlated with copper layer thickness and time using the forward model and then validated by the experiments together with SEM and AFM studies. Studies showed that the Cu layer thickness plays a crucial role in controlling the height of the Mo 2 C crystal while it is not that critical in changing the lateral dimension of the crystal. Beyond simply enhancing Mo 2 C crystal growth and property-processing relationship, this study demonstrated the synthesis of designer Mo 2 C, which can be tailored to the needs of specific applications. This forward model will enable us to further enhance and exploit the family of analogs of materials previously demonstrated by other methods.