How to make pip and pps capacitors

Abstract

The invention relates to a manufacture method for a PIP (poly-insulator-poly) capacitor, which comprises the following steps of: forming a shallow trench isolation structure in a substrate; depositing a first polycrystalline silicon on the shallow trench isolation structure; etching the first polycrystalline silicon to expose the edge of the shallow trench isolation structure; successively depositing a first medium layer, a second polycrystalline silicon and a second medium layer on the first polycrystalline silicon and the shallow trench isolation structure; successively etching the second medium layer, the second polycrystalline silicon and the first medium layer so as to form a first contact hole for exposing the top of the first polycrystalline silicon, etching the second medium layer so as to form a second contact hole for exposing the top of the second polycrystalline silicon; depositing metal on the surface of the above structure to form an interconnection line. According to the manufacture method for the PIP capacitor, a capacitor connected with the PIP capacitor in parallel is formed in the PIP capacitor so as to improve the unit-area capacitance.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing PIP and PPS capacitors. Background technique [0002] PIP (poly-insulator-poly, polysilicon-insulator-polysilicon) capacitor is a device widely used to prevent analog circuits from emitting noise and frequency modulation. Since the PIP capacitor has the lower and upper electrodes formed of polysilicon (the same material as the gate electrode of the logic circuit), the electrode of the PIP capacitor can be formed together with the gate electrode without a separate forming process. [0003] The PPS (Polypropylene film, polypropylene film) capacitor also has a lower electrode and an upper electrode formed of polysilicon (the same material as the gate electrode of the logic circuit), and the electrode of the PPS capacitor can also be formed together with the gate electrode without a separate forming process. [0004] Since the electrodes of the PIP...

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Problems solved by technology

[0005] In the existing electrically erasable programmable read-only memory (electrically erasable programmable ROM, EEPROM), PIP capacitors, PPS capacitors and transistor capacitors are widely used as capacitor devices, but generally, PIP capacitors are formed separately In the field area, the PPS capacitance is formed separately in the active area, and the transistor capacitance is generally formed separately. Since the capacitance per unit area is small, the only way to increase the capacitance is to increase the area of ​​the PIP capacitance or increase the area of ​​the PPS capacitance or increase the area of ​​the transistor capacitance, respectively. As a result, the chip area increases

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