Method of manufacturing a semiconductor capacitor having a hemispherical grain layer using a dry cleaning process

A method of manufacturing a semiconductor device having a hemispherical grain (HSG) layer employs a dry cleaning process. A polysilicon layer is formed on a specific material layer on a semiconductor substrate. Next, a polysilicon pattern, at least a portion of which is exposed, is formed by etching the polysilicon layer. The exposed surface of the polysilicon pattern is then dry cleaned by supplying hydrogen in a plasma state and a fluorine-based gas toward the exposed surface. The exposed surface of the polysilicon pattern may also be wet cleaned before being dry cleaned to wash away pollutants which may have been left thereon. An HSG layer is then formed on the cleaned surface of the polysilicon pattern. After the HSG layer is formed, the surface of the HSG layer may be dry cleaned again by supplying hydrogen in a plasma state and a fluorine-based gas toward the surface of the HSG layer. The surface of the HSG layer may also be further wet cleaned before being dry cleaned. Accordingly, the HSG layer is effectively cleaned without damaging or contaminating the HSG layer, thereby improving the reliability of the semiconductor device.