Focusing and leveling device and method

Abstract

The invention provides a focusing and leveling device which is used for the adjustment of a focal plane of a plane to be tested and the correction of a self zero plane. The focusing and leveling device comprises a light source module, an optical lens module, a tested object and a detector module, and is characterized in that the optical lens module comprises projection diaphragms, a focusing double-optical-wedge assembly, a projection optical assembly, a zero plane adjusting assembly and a detecting optical assembly, a light beam emitted from the light source module passes through the projection diaphragms, the projection optical assembly and first focusing double optical wedges, and then is reflected by the tested object so as to form a reflection light beam, and the reflection light beam sequentially passes through the projection optical assembly, the zero plane adjusting assembly and second focusing double optical wedges and then is received by the detector module. Meanwhile, the invention provides a focusing and leveling method.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit equipment manufacturing, in particular to a focusing measurement and control device and method for photolithography equipment. Background technique [0002] Photolithography, or photolithography, has been widely used in integrated circuit manufacturing processes. This technology exposes through a photolithography system to transfer the designed mask pattern to the photoresist. Since the feature size of the integrated circuit is ultimately determined, the lithography system is an important device in the integrated circuit manufacturing process, and its precision requirements are self-evident for the lithography process. In order to obtain the best imaging effect, during exposure, the silicon wafer coated with photoresist is adsorbed on the film holder, and its upper surface needs to be placed at the optimum image plane height. [0003] In the projection exposure equipment, there mu...

AI Technical Summary

Problems solved by technology

[0004] The publication date is January 9, 1996. Japanese patent JP5483056 provides a focusing and leveling device. The technical defects of this device are: first, when the bandwidth is relatively large, the blazed grating cannot be used, otherwise it will cause part of the light to pass through, and When the distance between the slits is relatively close, the crosstalk between the stages affects the measurement

Then, when the incident angle is greater than 80 degrees, when the right-angle prism is glued with the projection diaphragm, the chromatic aberration is difficult to control

Thirdly, in the process of optical-mechanical assembly and adjustment, there is no focusing mechanism, which puts forward higher requirements for assembly and processing

Finally, due to the influence of temperature and other environments, the best focal plane of the objective lens has drifted. If the focus and leveling are not corrected to its own zero plane, the center of the focus and leveling measurement point will not coincide with the exposure field of view of the objective lens, causing measurement Error (the difference between the actual Z, Rx, Ry of the current exposure field and the Z, Rx, Ry measured by focusing and leveling)

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