Methods of forming a floating junction on a solar cell with a particle masking layer

Abstract

A method of forming a floating junction on a substrate is disclosed. The method includes providing the substrate doped with boron atoms, the substrate comprising a front surface and a rear surface. The method also includes depositing a set of masking particles on the rear surface in a set of patterns; and heating the substrate in a baking ambient to a first temperature and for a first time period in order to create a particle masking layer. The method further includes exposing the substrate to a phosphorous deposition ambient at a second temperature and for a second time period, wherein a front surface PSG layer, a front surface phosphorous diffusion, a rear surface PSG layer, and a rear surface phosphorous diffusion are formed, and wherein a first phosphorous dopant surface concentration in the substrate proximate to the set of patterns is less than a second dopant surface concentration in the substrate not proximate to the set of patterns. The method also includes exposing the substrate to a set of etchants for a third time period, wherein the front surface PSG layer and the rear surface PSG layer are substantially removed; depositing a front surface SiNlayer and a rear surface SiNlayer; and forming a rear metal contact on the rear surface through the rear surface SiNlayer proximate to the set of patterns.