n+-n and n+-p junctions were formed on n-type and p-type Si using a thin film of phosphorus obtained from a simple vapor source, and driving in the dopant atoms in a rapid thermal processing (RTP) system. The vapor treatment consisted of heating powdered red phosphorus in a nitrogen ambient and allowing the resulting phosphorus vapor to deposit on the Si samples. This was done in an inexpensive apparatus constructed from flasks and test tubes. Following the vapor treatment, an SiOxfilm was sputtered over the phosphorus coating in order to serve as a capping layer during subsequent RTP drive-in that forms the junction. The junction properties were characterized by spreading resistance and electrical (IV and CV) measurements after deposition of metal contacts layers.