Method for manufacturing multilayer metal-oxide-metal capacitor

Abstract

The invention provides a method for manufacturing a multilayer metal-oxide-metal (MOM) capacitor. The method comprises the following steps of: forming a mixed layer of a low-k-value medium and high-k-value silicon oxide; forming a metallic groove in the low-k-value medium by using photolithographic etching of the conventional process, and filling a metal into the metal groove; repeating the above steps; and thus, obtaining the multilayer metal-oxide-metal capacitor. An MOM capacitor structure is realized in a high-k-value silicon oxide area, and the interconnection of the low-k-value media is realized in another area; the high-k-value silicon oxide is formed in a mode of plasma enhanced chemical vapor deposition (PECVD) and oxygen-containing gas processing circulation; and silicon-hydrogen bonds in the silicon oxide can be effectively removed. Compared with the conventional single-k-value medium structure, the method can improve the capacitance of an in-layer capacitor effectively, and improve the electrical characteristics such as breakdown voltage, leakage current and the like of the MOM capacitor, and the electrical uniformity between devices.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a method for manufacturing a multilayer metal-oxide-metal capacitor. Background technique [0002] Capacitors are commonly used electronic components in integrated circuits, and are also important components of integrated circuits. They can be widely used in memory, microwave, radio frequency, smart card, high voltage and filter chips. Currently, the capacitors widely used in chips are metal-insulator-metal (MIM) capacitors parallel to the silicon substrate. Among them, the metal usually adopts copper, aluminum, etc. that are compatible with the metal interconnection process, and the insulator is mostly a dielectric material with a high dielectric constant (k), silicon oxide or silicon nitride, and the plasma enhanced chemical vapor deposition method (PECVD, Plasma Enhanced Chemical Vapor Deposition) is widely used in thin film deposition in metal interconnection process because ...

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Problems solved by technology

[0004] The Chinese patent with the publication number CN101577227A discloses a method for improving the performance of aluminum-silicon nitride-tantalum oxide capacitors. The silicon nitride film is treated with an oxygen-containing gas, and the formed silicon nitride film has less charge, which improves the performance of the silicon nitride film. The electrical thickness and physical thickness of the silicon nitride film are uniform. The MIM capacitor formed by this method has improved in terms of breakdown voltage, leakage current and other electrical characteristics, but it has not obtained high-density capacitors.

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