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A Design Method of Alignment Marks to Improve Overlay Accuracy

A technology for aligning marks and design methods, which is applied to the photoengraving process of the pattern surface, the originals and instruments for opto-mechanical processing, etc., which can solve the problems such as the instability of the engraving accuracy of the quasi-mark position, and save the test run. Time, improve stability, reduce the effect of placement space

Active Publication Date: 2021-12-07
SHANGHAI HUALI INTEGRATED CIRCUTE MFG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for designing an alignment mark that improves the accuracy of the overlay, which is used to solve the problem of the space occupied by the position of the quasi-mark in the prior art and the lack of space due to the underlying film of the quasi-mark Instability leads to unstable overlay accuracy

Method used

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  • A Design Method of Alignment Marks to Improve Overlay Accuracy
  • A Design Method of Alignment Marks to Improve Overlay Accuracy
  • A Design Method of Alignment Marks to Improve Overlay Accuracy

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Embodiment 1

[0026] refer to Figure 4 , Figure 4 It is a schematic flowchart of an alignment mark design method for improving overlay accuracy of the present invention. The invention provides an alignment mark design method for improving overlay accuracy, the method at least includes the following steps:

[0027] Step 1. The alignment mark of the previous photoresist layer is placed at the first position; preferably, the shape of the alignment mark is a rectangle. Such as Figure 5 as shown, Figure 5 It is shown as a vertical cross-sectional view of the placement position design of the alignment mark of the present invention. Wherein, the alignment mark M1Mark of the previous layer M1 is at the first position, and the previous layer of the present invention includes the first metal layer. The shape of the alignment mark may be a rectangle, and the rectangle refers to a shape viewed from above the previous layer.

[0028] Step 2. When the layer is exposed, place the alignment mark ...

Embodiment 2

[0046] refer to Figure 4 , Figure 4 It is a schematic flowchart of an alignment mark design method for improving overlay accuracy of the present invention. The invention provides an alignment mark design method for improving overlay accuracy, the method at least includes the following steps:

[0047] Step 1. The alignment mark of the previous photoresist layer is placed at the first position; preferably, the shape of the alignment mark is a rectangle. Such as Figure 5 as shown, Figure 5 It is shown as a vertical cross-sectional view of the placement position design of the alignment mark of the present invention. Wherein, the alignment mark M1Mark of the previous layer M1 is at the first position, and the previous layer of the present invention includes the first metal layer. The shape of the alignment mark may be a rectangle, and the rectangle refers to a shape viewed from above the previous layer.

[0048] Step 2. When the layer is exposed, place the alignment mark ...

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Abstract

The invention provides an alignment mark design method for improving overlay accuracy, comprising: placing the alignment mark of the previous photolithographic layer at a first position; when the layer is exposed, placing the alignment mark at a second position, and simultaneously Expose the first position, and then fill the exposed first position with metal; when the third layer is exposed, put the alignment mark back to the first position, and at the same time expose the second position, and then fill the exposed first position The second position is filled with metal; the design of the alignment mark position when the subsequent layer is exposed can be analogized by analogy. The position placement of the alignment mark and the design of the stacking of the front and rear layers of the present invention can effectively reduce the placement space of the alignment mark, and at the same time make the underlying film of the alignment mark more stable, so it can improve the stability of the overlay accuracy, which is beneficial to daily life. Maintenance of running goods and improvement of overlay accuracy. In addition, the design of the alignment mark of the present invention is also beneficial to predict the overlay accuracy, save time for trial running of new products, and improve production capacity.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an alignment mark design method for improving overlay precision. Background technique [0002] The alignment system of the lithography machine is responsible for aligning the pattern on the mask (current layer) with the existing pattern (front layer) on the wafer to ensure accurate overlay between patterns after exposure. In an actual photolithography process, this alignment operation needs to be performed twice. The first time is coarse alignment, that is, selecting two alignment marks in a region on the wafer to align with two alignment marks on the reticle. The second step is fine alignment. Generally, the alignment marks in multiple exposure areas are selected to align with the marks on the reticle respectively, and the correction amount is calculated. Periodic patterns that can produce diffraction under alignment laser irradiation can be used as alignment marks. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G03F9/00G03F1/42
CPCG03F1/42G03F9/7076G03F9/7084
Inventor 赖璐璐钱睿
Owner SHANGHAI HUALI INTEGRATED CIRCUTE MFG CO LTD