Summary 10 steps: slicing, cleaning, preparation of suede, peripheral etching, removal of back PN + junction, fabrication of upper and lower electrodes, fabrication of antireflection film, sintering, testing
10 steps: slicing, cleaning, preparation of suede, peripheral etching, removal of back PN + junction, fabrication of upper and lower electrodes, fabrication of antireflection film, sintering, testing and grading
(1) Slicing: the silicon rod is cut into square silicon wafer by multi wire cutting.
(2) Cleaning: use the conventional silicon wafer cleaning method, and then use acid (or alkali) solution to remove the cut damage layer on the silicon wafer surface by 30-50um
(3) Preparation of suede: anisotropic etching of silicon wafer with alkali solution to prepare suede on the surface of silicon wafer.
(4) Phosphorus diffusion: the coating source (or liquid source or solid phosphorus nitride sheet source) is used for diffusion to make PN + junction, and the junction depth is generally 0.3-0.5um.
(5) Peripheral etching: the diffusion layer formed on the peripheral surface of the silicon wafer during diffusion will short circuit the upper and lower electrodes of the battery. The peripheral diffusion layer shall be removed by masking wet etching or plasma dry etching.
