We present an experimental analysis of Schottky-barrier metal-oxide-semiconductor field effect transistors(SBMOSFETs) fabricated on ultrathin body silicon-on-insulator substrates with a steep junction by the dopant implantation into the silicide process. The subthreshold swing of such SB-MOSFETs reaches 69 mV/dec. Emphasis is placed on the capacitance-voltage analysis of p-type SB-MOSFETs. According to the measurements of gate-to-source capacitance C_(gs) with respect to V_(gs) at various V_(ds), we find that a maximum occurs at the accumulation regime due to the most imbalanced charge distribution along the channel. At each C_(gs) peak, the difference between V_(gs) and V_(ds) is equal to the Schottky barrier height(SBH) for NiSi_2 on highly doped silicon,which indicates that the critical condition of channel pinching off is related with SBH for source/drain on channel. The SBH for NiSi_2 on highly doped silicon can affect the pinch-off voltage and the saturation current of SB-MOSFETs. We present an experimental analysis of Schottky-barrier metal-oxide-semiconductor field effect transistors (SBMOSFETs) fabricated on ultrathin body silicon-on-insulator substrates with a steep junction by the dopant implantation in the silicide process. The subthreshold swing of such SB- The MOSFETs reach 69 mV / dec. Emphasis is placed on the capacitance-voltage analysis of p-type SB-MOSFETs. According to the measurements of gate-to-source capacitance C_ (gs) with respect to V_ (gs) at various V_ ds), we find that a maximum occurs at the accumulation regime due to the most imbalanced charge distribution along the channel. At each C_ (gs) peak, the difference between V_ (gs) and V_ (ds) is equal to the Schottky barrier (SBH) for NiSi_2 on highly doped silicon, which indicates that the critical condition of channel pinching off is related to SBH for source / drain on channel. The SBH for NiSi_2 on highly doped silicon can affect the pinch-off voltage and the saturation current of SB-MOSFETs .