METHOD AND SYSTEM FOR REMOVAL OF A SURFACE LAYER OF A SILICON SOLAR CELL SUBSTRATE

摘要

A method of manufacturing a solar cell from a silicon wafer includes -formation of a dopant containing silicon layer, based on doping with dopant from a diffusion source, on at least one side of the silicon wafer, by exposing the at least one side of the silicon wafer to a dopant containing substance from the diffusion source, the dopant containing silicon layer comprising an upper layer of an ineffective conductive silicon layer having a relatively high concentration of dopant and a lower buried layer of a conductive silicon layer having a lower concentration of dopant, -back-etching of the dopant containing silicon layer by a back-etch etchant, the back- etch etchant having a first component and a second component, the back-etching comprising an oxidation reaction to transform a top layer of the dopant containing silicon layer into an oxide top layer by the first component and a dissolution reaction to remove the oxide top layer by the second component; the dissolution reaction being rate-limiting in the back-etch process.