Abstract: A method of forming a multi-doped junction on a substrate is disclosed. The method includes providing the substrate doped with boron atoms, the substrate comprising a front crystalline substrate surface; and forming a mask on the front crystalline substrate surface, the mask comprising exposed mask areas and non-exposed mask areas. The method also includes exposing the mask to an etchant, wherein porous silicon is formed on the front crystalline substrate surface defined by the exposed mask areas; and removing the mask. The method further includes exposing the substrate to a dopant source in a diffusion furnace with a deposition ambient, the deposition ambient comprising POCl3 gas, at a first temperature and for a first time period, wherein a PSG layer is formed on the front substrate surface; and heating the substrate in a drive-in ambient to a second temperature and for a second time period.