Low temperature epitaxial growth technique of Si an Si(111) for gas-source molecular beam epitaxy (GS-MBE) has been performed. It consists of low temperature growth followed by heat-pulse annealing to improve crystallinity and surface roughness of the films. Surface morphology investigated with tapping-mode atomic force microscopy (TM-AFM) is dependent on annealing temperature, annealing time, growth temperature and film thickness. An annealing temperature of 850 degrees C is sufficient to Batten a three-dimensional surface grown at 500 degrees C. Ordered terraces having straight step edge can he obtained by setting these parameters properly. Once terraces reach a certain width, further annealing has little influence on the terrace width. Heat-pulse annealing is effective for both improving the film crystallinity and ordering the terraces.