Overlapping capacitor and manufacturing method thereof

Abstract

The invention provides an overlapping capacitor and a manufacturing method thereof. The overlapping capacitor comprises an MOS capacitor, a PIP capacitor and at least one MIM capacitor which are connected in parallel in an overlapping manner. The MOS capacitor comprises a semiconductor substrate, wherein a well region serving as a lower electrode plate of the MOS capacitor is formed in the semiconductor substrate, a gate dielectric layer is formed on the semiconductor substrate, a first polycrystalline silicon layer is formed on the gate dielectric layer, and the first polycrystalline silicon layer serves as an upper electrode plate of the MOS capacitor. The PIP capacitor comprises the first polycrystalline silicon layer serving as a lower electrode plate of the PIP capacitor, wherein a PIP capacitor dielectric layer is formed on the first polycrystalline silicon layer, and a second polycrystalline silicon layer is formed on the PIP capacitor dielectric layer and serves as an upper electrode plate of the PIP capacitor. A first interlayer dielectric layer is formed on the PIP capacitor and the MOS capacitor, and the MIM capacitor is formed on the first interlayer dielectric layer. According to the overlapping capacitor provided by the invention, the specific capacitance is larger, and the development cost can be saved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a superimposed capacitor and a manufacturing method thereof. Background technique [0002] For metal-oxide-semiconductor (Metal-Oxide-Semiconductor, referred to as MOS) capacitors, polysilicon-insulator layer-polysilicon (Poly-Insulation-Poly, referred to as PIP) capacitors, metal-insulator-metal (Metal-Insulation-Metal, referred to as MIM) capacitors are widely used in the field of semiconductor manufacturing, but currently there are mainly three independent structures of capacitors. [0003] For the independent capacitor structure, the improvement of the unit capacitance needs to be achieved by replacing the material with a larger dielectric coefficient or reducing the thickness of the capacitor medium. Replacing dielectric materials requires greater process development costs, and the reduction of dielectric thickness is often limited by process capabilities. [0004] ...

AI Technical Summary

Problems solved by technology

Replacing dielectric materials requires greater process development costs, and the reduction of dielectric thickness is often limited by process capabilities

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