Tsinghua University applies for patent for photolithography machine grating measurement and calibration system
According to the announcement from the State Intellectual Property Office, Tsinghua University applied for a project called "A grating measurement and calibration system for lithography machines", with the public number CN117367746A, and the application date is September 2023.
The patent abstract shows that the present invention provides a photolithography machine grating measurement and calibration system, which relates to the technical field of grating measurement and includes a frame, a motion system with independent motion directions, a planar grating assembly, a grating reading head assembly, and a laser interferometer assembly. Following motion system, vacuum bellows assembly and reflector assembly, the vacuum bellows is installed on the following motion system and is located between the corresponding laser interferometer and the reflector, the following system is fixed on the frame and follows The motion system moves; the grating reading head assembly and the plane grating assembly are respectively fixed in the X direction and Y direction of the motion system. The grating reading head and the plane grating cooperate with each other and provide real-time feedback on the X- and Y-direction linear displacements of the calibrated part as well as the rotation angles around the X-, Y-, and Z-axes respectively, and compare the calibrated parts measured by the grating reading head and the laser interferometer. Calibration can be completed by linear displacement and rotation angle of (mirror assembly and plane grating assembly).
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