The role of an epitaxial growth technique in the performance of metal oxide semiconductor (MOS) devices was investigated. Using a pioneering method like selective epitaxy, the performance and integration of MOS devices found to be improved significantly. It is also seen that epitaxy is essential for realizing modern semiconductor device like FinFETs. The cheap and improved semiconductor structure like vertical MOSFET also required service of epitaxy technique. The stringent control of the epitaxial process was necessary for achieving the superlative performance and desiredstructures.