The invention discloses a high-sheet-resistance wet
oxygen diffusion method for obtaining low-concentration BSG, and belongs to the technical field of
solar cell preparation. A multi-step source introduction method is adopted, the source introduction time is shortened, the source introduction flow is increased, rapid heating promotion is achieved, and a wet
oxygen oxidation method and a low-temperature deposition method are innovatively adopted; wherein the low-temperature deposition method can slow the reaction
decomposition of an
impurity source and reduce the concentration of the
impurity source deposited on the surface of a
silicon wafer, so that the content of impurities diffused into a
silicon substrate is reduced, the effect of deep and shallow junctions is finally realized, and the method is an
effective method for preparing low-concentration shallow junctions and obtaining high
sheet resistance; according to the invention, high
sheet resistance with excellent uniformity is realized while the BSG with low
impurity concentration is obtained, the
process time is shortened, the subsequent LECO process is ensured to be more ideally realized, and finally, the battery conversion efficiency is improved to the maximum extent and the
process time is shortened to the maximum extent.