A manufacturing process of wafer thinning, comprising the steps of: wafer-grinding, grinding one of the faces of a wafer so as to make the wafer to have a first predetermined thickness; wherein the wafer-grinding includes following steps: 1) a step to inspect the wafer prior to the wafer-grinding (S1A); 2) a step of a wafer-taping process to adhere a film onto a first face of the wafer (S1B); and 3) a step to grind a second face of the wafer that does not have the film till the wafer achieves the first predetermined thickness, grinding is only applied to a central portion of the second face of the wafer with a several mm un-ground margin at a peripheral portion around the wafer (S1C); and wafer-etching, etching the second face of the wafer so as to make the wafer to have a second predetermined thickness; wherein the wafer-etching includes following steps: 1) a step of a chemical wet etching process to apply an etching solution to wet-etch the second face of the wafer so as to further reduce a thickness of the wafer to the second predetermined thickness (S2A); 2) a step of a first-time wafer cleaning process to clean the wafer (S2B); 3) a step of a first-time wafer drying process to dry the wafer (S2C); 4) a step of an etching process to achieve predetermined surface roughness so as to increase surface roughness of the second face of the wafer (S2D); 5) a step of a second-time wafer cleaning process to clean the wafer (S2E); and 6) a step of a second-time wafer drying process to dry the wafer (S2F); 7) a step of a wafer-pickling process to clean the wafer using an acidic cleaner (S2G); 8) a step of a third-time wafer cleaning process to clean the wafer (S2H); and 9) a step of a third-time wafer drying process to dry the wafer (S2I). wafer-grinding, grinding one of the faces of a wafer so as to make the wafer to have a first predetermined thickness; wherein the wafer-grinding includes following steps: 1) a step to inspect the wafer prior to the wafer-grinding (S1A); 2) a step of a wafer-taping process to adhere a film onto a first face of the wafer (S1B); and 3) a step to grind a second face of the wafer that does not have the film till the wafer achieves the first predetermined thickness, grinding is only applied to a central portion of the second face of the wafer with a several mm un-ground margin at a peripheral portion around the wafer (S1C); and wafer-etching, etching the second face of the wafer so as to make the wafer to have a second predetermined thickness; wherein the wafer-etching includes following steps: 1) a step of a chemical wet etching process to apply an etching solution to wet-etch the second face of the wafer so as to further reduce a thickness of the wafer to the second predetermined thickness (S2A); 2) a step of a first-time wafer cleaning process to clean the wafer (S2B); 3) a step of a first-time wafer drying process to dry the wafer (S2C); 4) a step of an etching process to achieve predetermined surface roughness so as to increase surface roughness of the second face of the wafer (S2D); 5) a step of a second-time wafer cleaning process to clean the wafer (S2E); and 6) a step of a second-time wafer drying process to dry the wafer (S2F); 7) a step of a wafer-pickling process to clean the wafer using an acidic cleaner (S2G); 8) a step of a third-time wafer cleaning process to clean the wafer (S2H); and 9) a step of a third-time wafer drying process to dry the wafer (S2I). 1) a step to inspect the wafer prior to the wafer-grinding (S1A); 2) a step of a wafer-taping process to adhere a film onto a first face of the wafer (S1B); and 3) a step to grind a second face of the wafer that does not have the film till the wafer achieves the first predetermined thickness, grinding is only applied to a central portion of the second face of the wafer with a several mm un-ground margin at a peripheral portion around the wafer (S1C); and 1) a step of a chemical wet etching process to apply an etching solution to wet-etch the second face of the wafer so as to further reduce a thickness of the wafer to the second predetermined thickness (S2A); 2) a step of a first-time wafer cleaning process to clean the wafer (S2B); 3) a step of a first-time wafer drying process to dry the wafer (S2C); 4) a step of an etching process to achieve predetermined surface roughness so as to increase surface roughness of the second face of the wafer (S2D); 5) a step of a second-time wafer cleaning process to clean the wafer (S2E); and 6) a step of a second-time wafer drying process to dry the wafer (S2F); 7) a step of a wafer-pickling process to clean the wafer using an acidic cleaner (S2G); 8) a step of a third-time wafer cleaning process to clean the wafer (S2H); and 9) a step of a third-time wafer drying process to dry the wafer (S2I).