Manufacturing method of multilayer metal-silicon oxide-metal capacitor

Abstract

The invention provides a manufacturing method of a multilayer metal-silicon oxide-metal (MOM) capacitor. Through forming a mixing layer of a low k value medium and high k silicon oxide, photolithography etching of a traditional technology is used to respectively form metal grooves in the low k value medium and the silicon oxide and the metal grooves are filled with metal. The above step is repeated so as to form the multilayer MOM capacitor. A MOM capacitor structure is realized in a high k silicon oxide area. Interconnection of the low k medium is realized in other areas. Plasma enhanced chemical vapor deposition (PECVD) and a mode of oxygen containing gas processing cycle operation are used to form the high k silicon oxide and Si-H in the silicon oxide can be effectively removed. Compared to a traditional single k value medium structure, by using the method of the invention, capacitance of the inner layer capacitor can be increased; various kinds of electrical characteristics of the MOM capacitor, such as a breakdown voltage, a leakage current and the like, can be improved; and electrical uniformity between devices can be improved too.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a method for manufacturing a multilayer metal-silicon 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 most widely used capacitors 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 pro...

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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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