Focusing and leveling sensor for projection photo-etching machine

Abstract

The invention relates to a photo-etching projector's focus plat tuning sensor and its technology, especially a focus plat tuning sensor with projection network and detection network. It comprises two mutually perpendicular branches with each branch comprises two measuring optical path and two reference optical path, wherein measuring optical path measures the height of relative projection objective's optimum focal surface of base plate surface, reference optical path measures the height of projection objective's surface, four optical paths of each branch shares imaging system, the measuring optical path has water opening which can change measuring flare.

Description

Technical field: [0001] The invention relates to a focusing and leveling sensor and a focusing and leveling technology of a projection photolithography machine, in particular to a focusing and leveling sensor with a projection grating and a detection grating. Background technique: [0002] Projection lithography machines for optical lithography are well known in integrated circuit fabrication facilities. In the projection lithography machine, the exposure beam illuminates the mask engraved with the integrated circuit pattern, and the mask is imaged on the substrate through the projection objective lens, so that the photoresist coated on the substrate is exposed, thereby copying the mask pattern to the substrate surface. [0003] The improvement of integrated circuit integration requires continuous reduction of lithography feature size, and the reduction of lithography feature size depends on the improvement of lithography resolution of projection lithography machine. Short...

AI Technical Summary

Problems solved by technology

Due to the fixed size of the measurement spot projected on the surface of the substrate by the focusing and leveling sensor described in the prior art [1] and the prior art [2], it cannot be directly measured Image 6 The inclination and / or height of the exposure area to be exposed in a, b, c, d in the exposure field

In the step-and-scan projection lithography machine, the measurement spots of the focusing and leveling sensors described in the prior art [1] and the prior art [2] have a large overlapping area, resulting in image 3 The distance between the two measurement spots in the y direction (scanning direction) shown in is small, which affects the measurement accuracy

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