The object of the invention is a process for P-type boron doping of silicon wafers placed on a support in the chamber of a furnace of which one end comprises a wall in which means for introducing reactive gases and a gas carrying a boron precursor in gaseous form are located, whereby said process comprises the stages that consist in: a) In the chamber, reacting the reactive gases with boron trichloride BCl3 that is diluted in the carrier gas at a pressure of between 1 kPa and 30 kPa, and a temperature of between 800° C. and 1100° C., for forming a boron oxide B2O3 glass layer, b) Carrying out the diffusion of atomic boron in silicon under an N2+O2 atmosphere at a pressure of between 1 kPa and 30 kPa. A furnace designed for the implementation of said doping process as well as its applications—the manufacturing of large boron-doped silicon slices, in particular for photovoltaic applications—is also claimed.