The boron-doped microcrystalline silicon (muc-Si:H) films have been deposited in a plasma-enhanced chemical vapor deposition system using hydrogen (H-2) as a diluent gas of silane (SiH4) and diborane (B2H6) as the dopant gas at several gas phase doping ratios. The structural properties of the films have been investigated by Raman measurements. The Raman spectroscopy revealed that the increase of diborane gas phase doping ratio to silane reduces the crystalline volume fraction (X-C) and changes the nature of the hydrogen bonded silicon in the films.