Failure analysis method for MIM capacitor

Abstract

The invention relates to a failure analysis method for an MIM capacitor. The MIM capacitor is positioned on a silicon substrate and comprises an upper pole plate, a lower pole plate and an insulating layer positioned between the upper pole plate and the lower pole plate. The silicon substrate also at least comprises a metal layer positioned above the MIM capacitor, and the upper pole plate and the lower pole plate are electrically connected with the first circuit region and the second circuit region of the metal layer respectively. The method comprises the following steps: (a) determining whether the lower pole plate is grounded or not, if not, performing a step (b); or else, performing a step (d); (b) looking for a power bus with the closest interlayer distance with the MIM capacitor; wherein the power bus comprises a grounding lead; (c) forming a circuit channel connecting the lower pole plate and the power bus; (d) by voltage contrast detection, determining the electric leakage area of the MIM capacitor. When the electric leakage area of the MIM capacitor is detected through voltage contrast, the condition of a smaller degree of electric leakage cannot be skipped, so that the method is convenient for observation and is more reliable.

Description

technical field [0001] The invention relates to the field of semiconductor processing and manufacturing, and more specifically, to a failure analysis method for a MIM capacitor device. Background technique [0002] The MIM (Metal-Insulator-Metal) capacitor structure is a capacitor structure formed between the interconnection layers of semiconductor devices, which is better compatible with the back-end process of semiconductor manufacturing. Therefore, it is widely used in CMOS processes such as radio frequency integrated circuits and semiconductor memories. [0003] In the MIM capacitor structure defined by two layers of photomasks, its basic structure is distributed from top to bottom as the first metal layer / intermetallic dielectric layer / MIM capacitor upper plate / MIM insulating layer / MIM capacitor lower plate / intermetallic Dielectric layer / second metal layer, where the upper and lower plates can be drawn out through Via (vertical through-hole interconnection technology) ...

AI Technical Summary

Problems solved by technology

[0006] In the above-mentioned MIM capacitor device, the entire MIM capacitor is basically surrounded by the insulating medium, even if the insulating medium between the upper and lower plates has a leakage area, but because there is no leakage path to the substrate, the leakage area with a small degree of leakage, It is difficult to observe through voltage contrast detection, and it is also difficult to accurately determine the relative position of the leakage area of ​​the MIM capacitor

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