Device and method for focusing and leveling based on microlens array

Abstract

The invention discloses a method and a device based on focusing and leveling of a lenticule array and belongs to the technical field of opto-electrical detection. The invention comprises an emitting part and a receiving part, wherein, the emitting part comprises a light source, a focusing lens, a pinhole filter, a beam expanding lens, an optimal entrance pupil device, a lenticule array and a steering mirror; the receiving part comprises a steering mirror, a lenticule array, a focusing lens, a scan mirror of a micro-opto-electro-mechanical-system (OMEMS), a pinhole filter and a detector. The invention adopts the optimal entrance pupil device to control light entrance quantity and then improve measuring light spot, or the quantity of the imaging point can be controlled by the state of a switch to adapt to different exposure viewing field; the invention adopts the lenticule array to replace a slit array; the scan mirror of the micro-opto-electro-mechanical-system (OMEMS) is adopted to replace the single lens scan; the difference receiving method is adopted and then the requirement for stability of the light source is decreased and higher measuring accuracy can be acquired.

Description

Technical field [0001] The invention relates to a focusing and leveling detection method and device used in a projection lithography system. Its main function is to perform high-precision detection of the distance between the surface of the exposed silicon wafer and the projection objective lens and the two-dimensional inclination angle of the silicon wafer , In particular, a focusing and leveling sensor with simultaneous measurement of multiple points, which belongs to the field of optical measurement. Background technique [0002] In the projection lithography system, the silicon wafer focusing and leveling measurement system is used in the lithography machine to measure the height and rotation angle (Z, θ) of the silicon wafer surface relative to the projection objective lens. X And θ Y ), forming a feedback system with three vertical actuators of the workpiece table, real-time control of the vertical position of the silicon wafer, to ensure that the current field of the silic...

AI Technical Summary

Problems solved by technology

This technology has the following shortcomings: First, the multi-slit array is imaged on the same surface through the same imaging system, and the imaging problem of large field of view needs to be considered in the optical design, which increases the difficulty of optical design; secondly, the single The scanning mirror scans all the light points uniformly through the receiving slit array, which makes it difficult to improve the measurement accuracy of a single point, thereby reducing the measurement accuracy of the system; also higher

Images