Capacitor structure and manufacturing method thereof

Abstract

The invention provides a capacitor structure and a manufacturing method thereof. Several trenches with high depth-to-width ratio are formed through etching a substrate, the residual substrate is takenas a first pole plate of the capacitor, then, a capacitor medium layer is formed at an inner wall of the trench, and finally, a conductive layer is formed in the trench to be used as a second pole plate of the capacitor. The manufacturing method of the capacitor structure, provided by the invention, can increase active area of the capacitor through regulating etching depth of the trench, and consequently improves capacitance density in unit area of the capacitor. Moreover, the method provided by the invention is simple in technological steps, is matched with the existing CMOS technological processes, and effectively reduces production cost.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a capacitor structure and a manufacturing method thereof. Background technique [0002] With the rapid increase in the integration of various functional circuits and the need for miniaturization of functional modules and components, integrated passive technology has become a solution to replace discrete passive devices to achieve device miniaturization. In various typical circuits, 80% of the components are passive components, which occupy nearly 50% of the area on the printed circuit board, and capacitors are the most common and most distributed components on the substrate, making the integration technology of capacitors Become the key technology of integrated passive technology. [0003] There are various structures of capacitors in integrated circuit chips, such as MOS field effect transistor capacitors, PIP (poly-insulator-poly) capacitors, variable junction capacitor...

AI Technical Summary

Problems solved by technology

However, it is obvious that as the thickness of the dielectric layer decreases, the electric field intensity borne by the dielectric material increases correspondingly under the same operating voltage.

The dielectric material has a certain degree of breakdown resistance. In order to obtain reliable devices and reduce the risk of breakdown damage, the degree of increasing the capacitance density by reducing the thickness of the dielectric is limited, and the reliability of breakdown resistance is sacrificed.

Third, under the structure of a single-layer capacitor, the undulating morphology or hemispherical grains are used to increase the area of ​​the capacitor plate per unit area, but this method can only increase the range, and the undulating morphology is harmful to Craftsmanship brings great difficulty

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