Asm Lithography

Asm Lithography B.v.

Stefan Wittekoek

Marinus Aart Van Den Brink

Henk F Linders

Theodorus A Fahner

An apparatus for projecting a mask pattern (MA) on a substrate (W) by means of a projection lens system (PL) is described, which apparatus comprises a device for aligning a mask alignment mark (M.sub.1, M.sub.2) with respect to a substrate alignment mark (P.sub.1, P.sub.2). Means (WE.sub.1, WE.sub.2) preventing phase differences due to reflections at the mask plate (MA) from occurring within the alignment beam portions received by a detection system (13, 13') are arranged in the path of selected alignment beam portions (b.sub.1, b.sub.1 ').

Apparatus for projecting a mask pattern on a substrate

A projection apparatus is described having a reference plate with a set of grating marks in X and Y directions for aligning with an exposure mask having similar marks, and having four detectors for each mark, and having a lens system for projecting only the relevant mark on the relevant detector. A method of projecting is also described in which the detection signals are simultaneously processed with other signals to result in a control signal to adjust image quality.

Apparatus for and method of projecting a mask pattern on a substrate

An apparatus for projecting a mask pattern (MA) on a substrate (W) by means of a projection lens system (PL) is described, which apparatus comprises a device for aligning a substrate alignment mark (P.sub.1 ; P.sub.2) with respect to a mask alignment mark (M.sub.1 ; M.sub.2), the projection lens system (PL) forming part of the alignment device. A correction element (25) is arranged in this system (PL) to compensate for the fact that this system (PL) is not optimized for the wavelength of the alignment beam (b).

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Bergeyk, Netherlands

Stefan Wittekoek