Memory device, method and aligning control system for photoetching aligning data detection

Abstract

The invention discloses a memory device, a method and an aligning control system for the photoetching aligning data detection. The device comprises a modulus sampling module, an annular buffer alignment, a data output register, a state register, a write pointer, a read pointer and a read-write pointer distance register. The memory device, the method and the aligning control system can avoid reading invalid light-intensity data, judge the overflowing state of data and prevent error aligning result from being used for overlay.

Description

technical field [0001] The present invention relates to the technical field of optical equipment, in particular to a storage device and method for lithography alignment data verification and an alignment control system including the storage device. Background technique [0002] Overlay accuracy is one of the key indicators of lithography machines. In order to achieve high overlay accuracy, the lithography machine needs a special alignment system. figure 1 It is a structural schematic diagram of the alignment system of the lithography machine. The alignment system enables on-axis and off-axis alignment. The light source for coaxial alignment is provided by the illumination subsystem 1, and the light IL is projected onto the reticle 2 attached to the mask table 3 along the optical axis AX, and irradiates the reference plate 8 fixed on the wafer stage 7 through the projection optical subsystem 4 , and transmit the light intensity signal to the alignment signal processing sub...

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Problems solved by technology

[0004] In the above patent, since the sampling data of the data acquisition module cannot be transmitted immediately, it is necessary to store the collected data in a cache

Due to the limited storage space of the cache and the uncertain timing of reading and writing, two unexpected phenomena may occur: 1. data overflow (data that has not been read is overwritten); 2. reading a piece of unstored valid data At this time, when the data processing module applies for light intensity data, it will get a light intensity data that is inconsistent with the position data or has a wrong value, which will lead to an error in the alignment result.

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