Periodic patterns and technique to control misalignment between two layers

摘要

A method and system to measure misalignment error between two overlying or interlaced periodic structures are proposed. The overlying or interlaced periodic structures are illuminated by incident radiation, and the diffracted radiation of the incident radiation by the overlying or interlaced periodic structures are detected to provide an output signal. The misalignment between the overlying or interlaced periodic structures may then be determined from the output signal.

主权项

1. A method for processing and measuring a device, said device having a first periodic structure, said method comprising:
measuring the first periodic structure by illuminating the first periodic structure with incident radiation and by detecting diffracted radiation from the illuminated portions of the first periodic structure; after the first periodic structure has been measured, forming a second periodic structure in a region of the device, where the first and second periodic structures are present in said region and said second periodic structure includes a first and a second portion, wherein the first portion is in the region where the first periodic structure is present and the second portion is in a second region where the first periodic structure is not present; measuring a relative position between the first and second periodic structures by illuminating the first and second periodic structures with incident radiation and by detecting diffracted radiation from the illuminated portions of the first and second periodic structures in said region; and measuring the second periodic structure by measuring said second portion of said second periodic structure in the second region.