Manufacturing method of multi-fold mask layer

Abstract

The invention provides a manufacturing method of a multi-fold mask layer, which comprises the steps of forming a groove through the stacking configuration of multiple layers of hard masks with different etching selection ratios and self-alignment, exposing the multiple layers of hard masks on the surface by a thinning process, and finally obtaining the multi-fold mask layer through selective etching. According to the manufacturing method of the multi-fold mask layer, a structure similar to an ox horn cannot be formed in the manufacturing process of spacing multiplication, and the accurate etching of the multi-fold mask layer can be greatly improved. According to the invention, the multi-fold mask layer is manufactured by utilizing different stacking configurations and etching speed ratio selection of the multiple mask layers and the method for forming the groove based on self-alignment, the characteristic size of the device can be effectively reduced, and the characteristic density ofthe device is increased. Meanwhile, three times and four times of spacing multiplication can be realized. In addition, the width adjustment of the gap can be realized by controlling the thickness of each mask layer.

Description

technical field [0001] The invention belongs to the field of semiconductor manufacturing, in particular to a method for manufacturing a multiple mask layer. Background technique [0002] With the continuous development of semiconductor technology, integrated circuits become smaller and denser, which provides many advantages for the performance of integrated circuits, but at the same time, due to the limitations of manufacturing equipment, the production of smaller and denser Large integrated circuits are becoming increasingly difficult and expensive to manufacture. Improved processes are therefore used to reduce feature size, thereby increasing the density of integrated circuits. [0003] Pitch doubling or pitch doubling is a method by which the capabilities of lithography can be extended beyond their minimum pitch. An existing method for fabricating a pitch multiplication mask layer includes the following steps: [0004] 1) providing a substrate 101 on which a bottom mas...

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Problems solved by technology

[0013] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for manufacturing a multiple mask layer, which is used to solve the problem of low precision in the manufacture of multiple mask layers in the prior art and the difficulty of further reducing the pitch The problem

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