A method of forming a semiconductor structure of a control gate is provided, including depositing a first dielectric layer overlying a substrate, forming a surface modification layer from the first dielectric layer; and forming semiconductor dots on the surface modification layer. The surface modification layer has a bonding energy to the semiconductor dots less than the bonding energy between the first dielectric layer and the semiconductor dots. Therefore the semiconductor dots have higher density to form on the surface modification layer than that to directly form on the first dielectric layer. And a semiconductor device is also provided to tighten threshold voltage (Vt) and increase programming efficiency.