Scanning tunneling microscopy has been used to investigate the influence of surface boron on silicon growth via chemical vapor deposition (CVD). The presence of boron‐induced reconstructions on the Si(001) surface dramatically changes the surface morphology during subsequent CVD growth of silicon using disilane at 815 K. Boron‐induced reconstructions inhibit the lateral diffusion of silicon atoms from terraces to step edges, leading to greatly enhanced island nucleation, and also reduce the local surface reactivity toward disilane. Strong segregation of boron to the growth surface allows the enhanced island nucleation to persist to subsequent terraces during multilayer CVD growth of silicon, producing a rough but epitaxial surface. ©1995 American Institute of Physics.