Patent ID: 11922262
Assignee: CHANGXIN MEMORY TECHNOLOGIES, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 13:
14. A method for inspecting a photomask, comprising:
providing a thickness measuring device for the photomask, wherein the thickness measuring device comprises a plurality of sensor modules arranged side by side, wherein the plurality of sensor modules measures a thickness of the photomask;
providing a barcode reading device to read a barcode on the photomask, wherein the barcode reading device checks a preset database to determine whether the barcode is included in the database; and
providing a calibration device, wherein the calibration device comprises a calibration rod and an electromagnet, wherein the calibration rod comprises a calibration stick and a calibration base, wherein the electromagnet is arranged to be at a bottom of the calibration base, and wherein the barcode reading device is calibrated by the calibration device.