MTM anti-fuse structure on through hole and preparation process thereof

Abstract

The invention relates to an MTM anti-fuse structure on a through hole and a preparation process thereof. The structure comprises a substrate and a device layer on the substrate. The device layer is pressed and covered by a fuse sealing body which is internally provided with a fuse lower electrode. A fuse upper electrode is arranged outside the fuse sealing body and is just above the fuse lower electrode. An anti-fuse dielectric structure and an anti-fuse bottom layer blocking body are arranged between the fuse upper electrode and the fuse lower electrode. The anti-fuse bottom layer blocking body coats the top end of the fuse lower electrode in the fuse sealing body. The anti-fuse dielectric structure is supported on the anti-fuse bottom layer blocking body, and the fuse upper electrode is supported on the anti-fuse dielectric structure. The structure of the MTM anti-fuse structure is compact, the times of lithography can be reduced, the process operation is simple, the process cost is reduced, the integration degree is raised, and the reliability of anti-fuse is improved.

Description

technical field [0001] The invention relates to an antifuse structure and a preparation process thereof, in particular to an MTM antifuse structure on a through hole and a preparation process thereof, belonging to the technical field of microelectronics. Background technique [0002] MTM antifuse is usually used in FPGA and PROM circuit products, and the antifuse unit in the circuit is programmed according to actual needs, so as to realize the logic function or storage function of the circuit. This type of circuit has the characteristics of strong confidentiality, good flexibility, and non-volatility, and has broad application prospects in aerospace and military fields. [0003] The MTM antifuse unit structure is located between two layers of metal wiring in the circuit. The antifuse unit is composed of an antifuse dielectric layer, two dielectric barrier layers and antifuse upper and lower electrodes. The antifuse unit is distributed from the top metal layer to the top laye...

AI Technical Summary

Problems solved by technology

[0005] In the antifuse structure, due to the contact hole process of the barrier metal and the top metal on the antifuse, the photolithography process of the process is added to the antifuse structure process, and the photolithography process has a very high tolerance Engraving accuracy requirements, overlay deviations can easily cause short-circuit failure of the upper and lower electrodes of the anti-fuse; in addition, due to the existence of contact holes, the contact area between the top metal and the upper barrier layer of the MTM anti-fuse is reduced, which affects the conductivity of the anti-fuse; The sidewall oxide layer formed by the antifuse contact hole is a part of the MTM antifuse structure. The existence of this part increases the lateral size of the antifuse structure and affects the integration of the antifuse unit.

[0006] In addition, the lithography process control of the antifuse contact hole is the key point of the antifuse structure process, and the overlay accuracy of lithography determines the yield and reliability of the antifuse. The engraving accuracy is high and the process is complicated, resulting in an increase in process cost

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