The standard "GB/T 6618-2009 Test method for film thickness and total film thickness change of silicon wafers" specifies the test method for film thickness and total Film thickness change of silicon wafers (including silicon single crystal cutting discs, grinding discs, polishing discs and epitaxial discs). The standard covers both discrete and scanning measurement methods, which are applicable to wafer sizes in accordance with GB/T 12964, GB/T 12965 and GB/T 14139. The standard also applies to Film thickness and total Film thickness change measurement of Miscellaneous specification silicon wafers when the instrument allows. Film thickness conformity and product mass in the wafer production process are ensured by standardizing measurement methods and related requirements.