As device size shrinks towards 10 nm feature size, ballistic transport and quantum interference effects are expected to play significant role in the operation of these nanoscale devices. It is, therefore, imperative to have a first principles device simulation tool that will take these effects into account. In this work, a fully quantum mechanical simulator based on Contact Block Reduction (CBR) method has been used to investigate the behavior of 10nm FinFET device in the ballistic regime of operation. Simulation results show the transformation of multiple channels into a single merged channel across the fin as the fin width is reduced gradually. Also we observe that short channel effects can be minimized by reducing the fin thickness which is evident from the device transfer characteristics for different fin thickness presented in this paper.