Trench type capacitor device and preparation method

Abstract

The invention provides a preparation method of a trench type capacitor device, a trench capacitor region comprises: a plurality of trenches and a capacitor structure, wherein the trenches penetrate through a first dielectric layer and end at a first metal interconnection layer, and the capacitor structure is located on the first dielectric layer and fills the trenches; a second dielectric layer with a first opening, a second opening penetrating through the second dielectric layer and the first dielectric layer and ending at a second metal interconnection layer, and an electrode interconnection layer filling the first opening and the second opening. The side wall of the side, close to the second opening, of the first opening is overlapped with an extension line of the side wall of the side of the second opening, so that the depth of the second opening is further increased, the opening size of the second opening is reduced, the capacitance value per unit area is effectively increased, and a high-performance trench type capacitor device is formed, thus having significant significance.

Description

technical field [0001] The invention relates to the field of semiconductor passive device manufacturing, and more specifically, to a trench capacitor device and a preparation method. Background technique [0002] A capacitor is a passive device used for energy storage and is widely used in semiconductor circuits such as coupling, filtering, resonance, integration and compensation. The number of photolithographic layers of the trench type capacitor device in the prior art is more than that of the flat capacitor device, resulting in an increase in the cost of the manufacturing process, such as figure 1 The process flow of the prior art trench capacitor device is shown, including capacitor trench photolithography, lower plate photolithography, capacitor dielectric layer / top plate photolithography, capacitor via photolithography and interconnect metal photolithography A total of 5 photolithography. Moreover, before the photolithography of the lower plate, coating and back-etch...

AI Technical Summary

Problems solved by technology

[0003] figure 2 Shown is the cross-sectional view of the trench capacitor device in the prior art after the photolithography of the lower electrode layer is completed. Usually, the dry or wet stripping process is used to remove the BARC and photoresist filled in the trench, and the dry process is used. During the process, the plasma is easy to cause plasma damage to the lower electrode layer

In addition, in order to increase the capacitance per unit area, the trench opening is reduced while increasing the depth of the trench capacitor device, thus making it difficult to remove the BARC and photoresist in the trench, and it is easy to form BARC residues and Photoresist residue, which ultimately affects the reliability and yield of trench capacitor devices

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