SEMICONDUCTOR DEVICE COMPRISING METAL-BASED eFUSES OF ENHANCED PROGRAMMING EFFICIENCY BY ENHANCING METAL AGGLOMERATION AND/OR VOIDING

Abstract

Metal fuses in semiconductor devices may be formed on the basis of additional mechanisms for obtaining superior electromigration in the fuse bodies. To this end, the compressive stress caused by the current-induced metal diffusion may be restricted or reduced in the fuse body, for instance, by providing a stress buffer region and / or by providing a dedicated metal agglomeration region. The concept may be applied to the metallization system and may also be used in the device level, when fabricating the metal fuse in combination with high-k metal gate electrode structures.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present disclosure generally relates to the field of fabricating integrated circuits, and, more particularly, to forming electronic fuses for providing device internal programming capabilities in complex integrated circuits.[0003]2. Description of the Related Art[0004]In modern integrated circuits, a very high number of individual circuit elements, such as field effect transistors in the form of CMOS, NMOS, PMOS elements, resistors, capacitors and the like, are formed on a single chip area. Typically, feature sizes of these circuit elements are decreased with the introduction of every new circuit generation, to provide currently available integrated circuits with an improved degree of performance in terms of speed and / or power consumption. A reduction in size of transistors is an important aspect in steadily improving device performance of complex integrated circuits, such as CPUs. The reduction in size of the trans...

AI Technical Summary

Benefits of technology

[0022]Generally, the present disclosure provides electrically programmable metal fuses in a semiconductor device, wherein the programming efficiency, i.e., a required high reliability of causing and preserving a programmed state of the metal fuse, may be enhanced, while at the same time an overall compact configuration may be achieved. To this end, the present disclosure considers the incorporation of efficient stress-reducing mechanisms for reliably inducing an electromigration effect, i.e., a significant migration or diffusion of metal atoms and ions in the fuse body, while the overall dimensions, and in particular the effective length, of the fuse body may be reduced compared to conventional approaches in which, for a given cross-sectional area and material composition of a metal line, the length thereof may be increased to be well above the Blech length, which, however, may result in a considerable consumption of valuable chip area. A significant reduction of the overall dimensions, and in particular of the length, of a fuse body may be accomplished by reducing the compressive stress that is created upon initiating an electromigration effect, thereby facilitating the creation of voids in the fuse body, and, thus, causing a significant line degradation, which may, therefore, be reliably identified as a programmed state of the metal fuse. The reduction of the compressive stress in the metal fuse, which may, thus, enable a superior metal accumulation, may be achieved on the basis of “passive” and / or “active” mechanisms. For instance, a passive stress reduction or limitation mechanism may be provided in the form of stress buffer regions or reservoirs that are efficiently mechanically coupled to the fuse body, in which a material depletion is to be initiated. In other cases, the compressive stress-reducing mechanism may be established in addition to or alternatively to a passive mechanism by intentionally providing a metal accumulation volume or region at the time of programming the fuse, wherein the diffusing metal may actually leave the fuse body and may migrate into the surrounding dielectric material or into specifically provided metal accumulation voids. Consequently, by actively initiating the extrusion of the migrating metal from the fuse body, superior conditions with respect to maintaining an efficient line degradation effect also may be achieved at the time of programming the fuse, due to significantly reduced resulting compressive stress in the fuse body, thereby reliably activating a programmed state, while at the same time a re-diffusion of metal may be significantly reduced. In some illustrative aspects disclosed herein, the activation of the extrusion mechanism may be accomplished by providing an extrusion line or region in close proximity to the fuse body, thereby facilitating an electrical breakdown of the insulating material, which in turn may result in the weakening of a corresponding interface between the fuse body and the dielectric material. Consequently, an efficient diffusion path for the migrating metal atoms may be generated in a highly controllable manner, thereby also enabling a very compact overall configuration of the metal fuse.

[0025]One illustrative method disclosed herein relates to electrically programming a fuse in a semiconductor device. The method comprises establishing a current flow in a fuse body of the fuse to initiate a current-induced metal diffusion. The method further comprises reducing a compressive stress in the fuse body, wherein the compressive stress is caused by the current-induced metal diffusion.

Problems solved by technology

To this end, the present disclosure considers the incorporation of efficient stress-reducing mechanisms for reliably inducing an electromigration effect, i.e., a significant migration or diffusion of metal atoms and ions in the fuse body, while the overall dimensions, and in particular the effective length, of the fuse body may be reduced compared to conventional approaches in which, for a given cross-sectional area and material composition of a metal line, the length thereof may be increased to be well above the Blech length, which, however, may result in a considerable consumption of valuable chip area.

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