NOVELTY - Masking particles are deposited on the rear surface of a substrate (310), heated to create a particle masking layer (317), and exposed to phosphorus deposition ambient to form front surface phosphosilicate glass (PSG) layer, front surface phosphorus diffusion (308), rear surface PSG layer, and rear surface phosphorus diffusion (312). Substrate is exposed to etchants and PSG layers are removed. A front surface silicon nitride layer (304) and a rear surface silicon nitride layer (314) are deposited. A rear metal contact (316) is formed on rear surface.    USE - Formation of floating junction on substrate of solar cells.    ADVANTAGE - The method forms a rear floating junction on a silicon substrate with a particle masking layer, such that a rear metal contact fired through the rear silicon nitride layer does not detrimentally shunt the solar cell.    DETAILED DESCRIPTION - A substrate doped with boron atoms and comprising a front surface and a rear surface, is provided. A set of masking particles is deposited on the rear surface in a set of patterns. The substrate is heated in a baking ambient to temperature (I) for time period (I) to create a particle masking layer. The substrate is exposed to a phosphorus deposition ambient at temperature (II) for time period (II), and a front surface phosphosilicate glass (PSG) layer, a front surface phosphorus diffusion, a rear surface PSG layer, and a rear surface phosphorus diffusion are formed. Phosphorus dopant surface concentration (I) in the substrate proximate to the set of patterns is less than dopant surface concentration (II) in the substrate not proximate to the set of patterns. The substrate is exposed to a set of etchants for time period (III), and the front surface PSG layer and rear surface PSG layer are removed. A front surface silicon nitride layer and a rear surface silicon nitride layer are deposited. A rear metal contact is then formed on the rear surface through the rear surface silicon nitride layer proximate to the set of patterns.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a front-contact solar cell with a rear floating junction in which a particle masking layer is deposited prior to phosphorus diffusion.    Front surface silicon nitride layer (304)    Front surface phosphorus diffusion (308)    Substrate (310)    Rear surface phosphorus diffusion (312)    Rear surface silicon nitride layer (314)    Rear metal contact (316)    Particle masking layer (317)