TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Processes: Method further comprises (d) cleaning polysilicon chip after removing damaged layer. Pre-step (b) specifically involves passing through mixed solution of 0.1-8 mol/L, preferably 2-3 mol/L hydrofluoric acid and 0.1-10 mol/L, preferably 5-7 mol/L oxidizing agent to remove damage layers in which oxidizing agent is nitric acid, chromium trioxide (CrO3), or potassium dichromate (K2Cr2O7), preferably nitric acid; etching time is 20-60 seconds, preferably 30-40 seconds; and etching temperature is - 10-- 30 degrees C, preferably 3-10 degrees C. Pre-step (b) further involves passing through base corrosion solution which contains 0.1-10 mol/L base which is sodium hydroxide or potassium hydroxide, etching time is 5-20 minutes, preferably 8-15 minutes, temperature corrosion 20-90 degrees C, preferably 50-80 degrees C. Step (c) specifically involves passing through mixed solution of 0.1-8 mol/L, preferably 3-8 mol/L hydrofluoric acid and 0.1-10 mol/L, preferably 0.2-1 mol/L oxidizing agent to remove damage layers in which oxidizing agent is nitric acid or chromium trioxide (CrO3) or potassium dichromate (K2Cr2O7), preferably nitric acid; etching time is 20-60 seconds, preferably 22-25 seconds; and etching temperature is - 10-- 30 degrees C, preferably 0-3 degrees C. Step (d) specifically involves immersing in caustic base solution at 15-30 degrees C for 20-30 seconds, preferably 23-28 seconds, in which base is potassium hydroxide or sodium hydroxide at concentration of 1-4 mol/L, preferably 2.-2.5 mol/L, immersing in mix solution of 0.5-5 mol/L, preferably 1-4 mol/L hydrofluoric acid and 1-8 mol/L, preferably 2.5 mol/L hydrochloric acid at 15-30 degrees C, preferably20-25 degrees C for 1-20 minutes, preferably 9-12 minutes. Preferred Parameters: Sand in blasting chamber is quartz sand or silicon carbide sand with particle size of 10-100 mu m. Chamber has blasting nozzle that blasts sand to polysilicon chip with injection pressure of 0.03-0.3 MPa.