Manufacturing method of metal-oxide-metal capacitor

Abstract

The invention provides a manufacturing method of a metal-oxide-metal (MOM) capacitor. A mixed layer composed of low k-value dielectrics and high k-value silicon oxide is formed, metal grooves are formed in the low k-value dielectrics and the high k-value silicon oxide by the conventional photoetching process and filled with metals, so that a high-performance MOM capacitor structure is formed in the high k-value silicon oxide region, and the low k-value dielectrics are interconnected in other regions. The invention is characterized in that the high k-value silicon oxide is formed by means of PECVD (plasma enhanced chemical vapor deposition) and oxygen-containing gas processing cycles, which can effectively eliminate Si-H bonds in silicon oxide. Compared with the conventional single k-valuedielectric structure, the capacitance of the interlayer capacitor is effectively increased, the electrical properties (such as breakdown voltage and drain current) of the MOM capacitor are improved, and the uniformity of electrical properties between devices is improved.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a method for manufacturing a 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 of its low ...

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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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