Real-time leveling system suitable for projection photoetching machine and leveling method of real-time leveling system

Abstract

The invention discloses a real-time leveling system suitable for a projection photoetching machine. In the real-time leveling system, a light source forms parallel light beams through a first collimating lens assembly and a second collimating lens assembly to form a slit light beam through a projection diaphragm; the slit light beam is imaged on the surface of a silicon wafer through a first imaging lens assembly; the light beam reflected from the surface of the silicon wafer is imaged on a linear array charge coupled device (CCD) through a second imaging lens assembly, a third imaging lens assembly and a fourth imaging lens assembly; when deflection angle [alpha] exists between the silicon wafer and a workbench, and the reflection light beam reflected from the silicon wafer can deviates by an angle of 2[alpha]; during the deviation, a slit image generates a displacement of Delta X on the linear array CCD; the linear array CCD transmits image information onto an image acquisition control card through a Cameral link transmission line; the image acquisition card is used for sub-pixel processing on the image information to calculate a deviation angle of the silicon wafer; a silicon wafer table is leveled in real time by controlling a piezoelectric actuator below the silicon wafer table, and the flatness requirement of the silicon wafer during exposure is ensured. By the real-time leveling system, the real-time leveling efficiency of the photoetching machine during working is effectively improved, and thus, the working efficiency of the photoetching machine is improved.

Description

technical field [0001] The invention belongs to the technical field of leveling projection lithography machines in microelectronic equipment, and in particular relates to a real-time leveling system and a leveling method suitable for projection lithography machines. The application of the system can quickly realize the adjustment of silicon wafer stages Flat, improve the work efficiency of the lithography machine and the quality of the lithography process. Background technique [0002] At present, the scale of integrated circuits is getting bigger and bigger, and the circuit density per unit area is increasing sharply. In order to meet this requirement, the feature size of lithography lines is also getting smaller and smaller, which puts forward more stringent requirements for lithography resolution. At the same time, the improvement of resolution leads to a sharp drop in depth of focus, which makes the leveling and focusing requirements of the lithography system more string...

AI Technical Summary

Problems solved by technology

Even with a leveling system, real-time leveling cannot be achieved

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