A method for forming a monitoring reference mark, a monitoring reference mark, and a three-dimensional memory

Abstract

The embodiment of the present application discloses a method for forming a monitoring reference mark, a monitoring reference mark, and a three-dimensional memory, wherein the method is applied to the formation process of a three-dimensional memory, including: providing a semi-finished semiconductor, the semiconductor including a substrate and a deposition A stacked structure on the substrate; through the formation process of the top selection gate trench of the three-dimensional memory, a monitoring reference mark is formed at a specific position on the top of the stacked structure; wherein, the monitoring reference mark Embedded in the top of the stacked structure; through the formation process of the ladder structure of the three-dimensional memory, the top of the stacked structure including the monitoring reference mark is etched, so that the monitoring reference mark is on the The top of the laminated structure protrudes.

Description

Technical field[0001]The present application embodiments relate to but are not limited to, in particular, in particular, to a monitoring reference mark forming method and a monitoring reference mark, a three-dimensional memory.Background technique[0002]In the three-dimensional memory process, the effective storage area size of the step structure is millimeters, but after the lithography and etching process, the key size of the ladder structure will shrink hundreds of nanometers, and the related art will usually pass. Set the monitoring reference tag to monitor the key size of the effective storage area of ​​the step structure, but it is still difficult to monitor for the key size of the nanometer. Since the contact point size of the ladder structure is nanometer, and the change in the critical step structure is required, the change in the key size of the step structure is large, and the risk of the ladder structure is large, so it is necessary to be more accurate. Survey the change ...

AI Technical Summary

Problems solved by technology

[0002] In the three-dimensional memory process, the effective storage area of ​​the stepped structure is on the order of millimeters, but after photolithography and etching processes, the critical dimension of the effective storage area of ​​the stepped structure will be reduced by several hundred nanometers. Setting monitoring reference marks to monitor the critical dimensions of the effective storage area of ​​the ladder structure, but it is still difficult to accurately monitor the critical dimensions of the nanometer scale

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