1. Field of the Invention
The present invention relates generally to a semiconductor process, and more specifically, to a semiconductor process, which applies a thermal treatment process to make the sidewalls of fin-shaped structures smoother.
2. Description of the Prior Art
With increasing miniaturization of semiconductor devices, various Fin-shaped field effect transistor (FinFET) devices have been developed. The Fin-shaped field effect transistor (FinFET) is advantageous for the following reasons. First, manufacturing processes of Fin-shaped field effect transistor (FinFET) devices can be integrated into traditional logic device processes, and thus are more compatible. In addition, since the three-dimensional structure of the FinFET increases the overlapping area between the gate and the substrate, the channel region is controlled more effectively. This therefore reduces drain-induced barrier lowering (DIBL) effect and short channel effect. Moreover, the channel region is longer for the same gate length. Therefore, the current between the source and the drain is increased.
The methods of forming the fin-shaped structures of the FinFET include: a lithography process is performed to pattern a mask layer on a substrate. The patterns of the patterned mask layer are transferred to the substrate by using the patterned mask layer as a hard mask, so that at least a fin-shaped structure is formed on the substrate. However, the surfaces of the sidewalls of the fin-shaped structure formed by the lithography process are unsmooth and have defects formed as etching causes a bad quality of the channel region and causes layers to not cover the fin-shaped structure closely, therefore reducing the electrical performance of the semiconductor structure formed on the fin-shaped structure.