NOVELTY - Manufacturing a solar cell from a silicon wafer comprises providing a diffusion source comprising a dopant containing substance; forming a dopant containing silicon layer, based on doping from the diffusion source, on at least one side of the silicon wafer, by exposing the at least one side of the silicon wafer to the dopant containing substance from the diffusion source; and back-etching of the upper layer of the ineffective conductive silicon layer comprised in the dopant containing silicon layer by a back-etch etchant.    USE - The method and system are useful for manufacturing a solar cell from a silicon wafer (claimed).    ADVANTAGE - The etching process in which the back-etching of the ineffective conductive silicon layer can be done in a controlled manner, due to rate-limitation of the back-etch process by the dissolution reaction. The improved control of the back-etching process allows controlling the removal rate and the removed layer thickness with increased precision. The manufacturing method described above allows implementing the stages of the method as an in-line process along a track to be followed by the silicon wafer. The method also allows implementing the stages of the method as batch type process in which the wafer is transported along consecutive stations.    DETAILED DESCRIPTION - Manufacturing a solar cell from a silicon wafer comprises providing a diffusion source comprising a dopant containing substance; forming a dopant containing silicon layer, based on doping from the diffusion source, on at least one side of the silicon wafer, by exposing the at least one side of the silicon wafer to the 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; and back-etching of the upper layer of the ineffective conductive silicon layer comprised in the dopant containing silicon layer by a back-etch etchant, the back-etch etchant comprising a first component and a second component, the back-etching comprising an oxidation reaction to transform a top layer of the upper layer of the ineffective conductive silicon layer comprised in 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. An INDEPENDENT CLAIM is a system of manufacturing a solar cell from a silicon wafer comprising a production track provided with: a diffusion furnace, the diffusion furnace being arranged for providing a diffusion source comprising a dopant containing substance and forming a dopant containing silicon layer, based on doping from the diffusion source, on at least one side of the silicon wafer, by exposing the at least one side of the silicon wafer to the dopant containing substance from the diffusion source, the dopant containing silicon layer comprising an upper layer of a less effective 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; and a back-etch etching reactor disposed in the production track after the etching station, being arranged for back-etching of the upper layer of the ineffective conductive silicon layer comprised in the dopant containing silicon layer by a back-etch etchant, the back-etch etchant comprising a first component and a second component, the back-etching comprising an oxidation reaction to transform a top layer of the upper layer of the ineffective conductive silicon layer comprised in the dopant containing silicon layer into an oxide top layer by the first component and a dissolution reaction to dissolve the oxide top layer by the second component; the dissolution reaction being rate-limiting in the back-etching process.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram of a method of manufacturing a solar cell.    Cleaning (101)    Diffusing (102)    Back-etching (103)    Removing (104)    Processing (105)