Alignment scanning method for alignment mark

Abstract

The invention discloses an alignment scanning method for an alignment mark. The method comprises the following steps that: 1, an alignment operation and management module transmits scanning parameters to a signal acquisition and processing module and a position acquisition and motion control module; 2, the position acquisition and motion control module plans a motion track comprising a scanning track in the process of scanning various sub-gratings and a transition track connected with different scanning tracks according to the scanning parameters and performance indexes of a motion table, and reaches an agreement with the alignment operation and management module to finish synchronous negotiation; 3, the motion table takes place and moves under the control of the position acquisition and motion control module according to the planned motion track; 4, the position acquisition and motion control module acquires position information for alignment and transmits the information to the alignment operation and management module, the signal acquisition and processing module acquires light intensity signals and transmits the light intensity signals to the alignment operation and management module; and 5, the alignment operation and management module calculates an alignment position of the mark according to the light intensity signals of a plurality of marked sub-gratings and the position information.

Description

technical field [0001] The invention relates to photolithographic devices in the field of integrated circuit or other micro-device manufacturing, in particular to an alignment scanning method for alignment marks. Background technique [0002] In the manufacturing process of semiconductor IC integrated circuits, a complete chip usually needs to undergo multiple photolithography exposures before it can be completed. Except for the first photolithography, the photolithography of other levels must be accurately positioned before exposure, so as to ensure the correct relative position between the graphics of each layer. Instant overlay accuracy. Normally, the overlay accuracy is 1 / 3 to 1 / 5 of the resolution index of the lithography machine. For a 100nm lithography machine, the overlay accuracy index is required to be less than 35nm. Overlay accuracy is one of the main technical indicators of a projection lithography machine, and the alignment accuracy between the mask and the s...

AI Technical Summary

Problems solved by technology

The two simultaneous negotiations, positioning and acceleration of the moving table will take more time, reduce the alignment efficiency, and ultimately affect the productivity of the lithography machine

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