Provided are methods of forming semiconductor devices. A method may include preparing a semiconductor substrate including a first region and a second region adjacent the first region. The method may also include forming sacrificial pattern covering the second region and exposing the first region. The method may further include forming a capping layer including a faceted sidewall on the first region using selective epitaxial growth (SEG). The faceted sidewall may be separate from the sacrificial pattern. The sacrificial pattern may be removed. Impurity ions may be implanted into the semiconductor substrate.