Semiconductor structure for testing mim capacitance

Abstract

A semiconductor structure for testing MIM capacitance, which is divided into multiple layers, including: a first metal layer, at least including a first circuit area and a second circuit area; a second metal layer, arranged on the first Below the metal layer, it is electrically connected to the second circuit area; the upper plate is located in the dielectric layer close to the first metal layer, and is electrically connected to the first circuit area; the lower plate is arranged opposite to the upper plate. In the dielectric layer close to the second metal layer, it is separated from the upper plate by an insulating layer and electrically connected to the second circuit area; the structure is formed on a P-type substrate, and the second metal layer is connected to the semiconductor substrate. The bottom is electrically connected by a first circuit path to form a second circuit path from the upper plate to the semiconductor substrate when there is a leakage region in the insulating layer. The method can accurately detect whether there is a leakage area in the MIM capacitor; the preparation is simple and the cost is low; and it is especially suitable for quickly locating the leakage area of ​​a large-area MIM capacitor.

Description

technical field [0001] The invention relates to the field of semiconductor processing and manufacturing, and more specifically relates to a semiconductor structure for testing MIM capacitors. 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 techn...

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Problems solved by technology

[0006] On the one hand, according to the traditional MIM capacitor design, 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 voltage contrast cannot be passed. detected, making it difficult to determine the relative location of leakage regions in bulk MIM capacitors

On the other hand, if the method of peeling off the upper plate of the MIM capacitor layer by layer, and then using the voltage contrast to observe the upper plate to confirm whether there is a leakage path to the substrate, for ordinary MIM capacitor breakdown , the abnormality of the MIM area can be basically observed, but it is powerless for the case of a small degree of leakage

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