Capacitors and how to form them

Abstract

Provided are a capacitor and a forming method thereof. The forming method of the capacitor includes: forming a first groove in a substrate; forming a first medium layer covering the substrate and a lateral wall and the bottom of the first groove; forming a first electric conduction layer covering the first medium layer and a first sacrificial layer arranged on a lateral wall of the first electric conduction layer; repeating the steps of forming the first electric conduction layer and the first sacrificial layer, and forming a plurality of first electric conduction layers and first sacrificial layers on the first medium layer sequentially; removing a plurality of electric conduction layer portions and first sacrificial layer portions higher than the surface of the first electric conduction layer at the bottom layer on a semi-conductor substrate; removing the remaining plurality of first sacrificial layer portions to form a plurality of second grooves; and forming a second medium layer and a top electric conduction layer on the second medium layer, covering a middle electric conduction layer, and filling the plurality of second grooves. Capacitance of the whole formed capacitor is large, and by means of the forming method, the number of used photoetching masks is reduced, and production cost is obviously reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for forming a capacitor and the capacitor. Background technique [0002] In addition to using transistors as active devices in integrated circuits, capacitors are often used as passive devices in semiconductor devices. For example, in integrated circuit design, a large-capacity capacitor is usually used as a decoupling capacitor, and the decoupling capacitor is equivalent to a battery to avoid a voltage drop due to a sudden change in current. Specifically, the capacitance C=εS / d, and the capacitance C is proportional to the surface area S of the capacitor plate, so a larger surface area of ​​the plate is required to manufacture a large-capacity capacitor. [0003] While integrated circuit design and development using capacitors is common, capacitors, like other active devices, are affected by the continuing need to shrink device and structure dimensions while inc...

AI Technical Summary

Problems solved by technology

That is to say, the number of layers of the polysilicon layer is equal to the number of times of patterning, the more layers, the more times of patterning, and each time of patterning requires a photolithography process, which increases the manufacturing cost

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