MIM (metal-insulator-metal) capacitor and manufacturing method thereof

Abstract

Disclosed are a MIM capacitor and a manufacturing method thereof. The manufacturing method includes: setting a covering layer on a second conducting layer (used for forming an upper electrode plate of an MIM capacitor). Etching gas which is slower in etching the covering layer than etching dielectric layers is selected in the process of dry etching performed to form through holes respectively exposing a first conducting layer (a lower electrode plate) and a second conducting layer, so that excessive etching of the second conducting layer (the upper electrode plate) is avoided when the dielectric layers embedding the second conducting layer and the first conducting layer are etched simultaneously at the same height. Thus, probability of breakdown of the MIM capacitor is lowered, and reliability of the MIM capacitor is increased.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a MIM capacitor and a manufacturing method thereof. Background technique [0002] Passive devices such as resistors and capacitors are widely used in integrated circuit manufacturing technology. These devices usually use standard integrated circuit technology, using conductive materials such as doped monocrystalline silicon and doped polysilicon, and insulating oxide films or oxynitride films. Made of materials, such as PIP (Poly-Insulator-Poly) capacitors. These devices are relatively close to the silicon substrate, and the parasitic capacitance between the device and the substrate will affect the performance of the device, especially in radio frequency (RF) circuits, as the frequency increases, the performance of the device degrades rapidly. [0003] The proposal of MIM (Metal-Insulator-Metal) capacitor technology provides an effective way to solve this problem. Thi...

AI Technical Summary

Problems solved by technology

As the manufacturing process progresses, due to the existence of the height difference between the upper and lower plates 102 and 101, the via holes will be etched. When the layer 103 is discharged, the potential difference between the upper and lower plates 102 and 101 begins to decrease until the through hole is etched and contacts the lower electrode plate 101. In severe cases, the above discharge process will break down the dielectric layer 103, resulting in a short circuit of the MIM capacitor

The above two problems will seriously affect the performance and reliability of MIM capacitors, especially for some products, the number of MIM capacitors is large, and its area reaches more than 10% of the overall area of ​​the device. Any short circuit or reliability problem of any MIM capacitor will be serious. Affects the yield and reliability of the entire product

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