Leakage current reduction in stacked metal-insulator-metal capacitors

Abstract

Capacitors and methods of forming the same include forming a dielectric layer on a first metal layer. The dielectric layer is oxygenated such that interstitial oxygen is implanted in the dielectric layer. A second metal layer is formed on the dielectric layer. The dielectric layer is heated to release the interstitial oxygen and to oxidize the first and second metal layers at interfaces between the dielectric layer and the first and second metal layers.

Description

BACKGROUNDTechnical Field[0001]The present invention generally relates to stacked metal-insulator-metal capacitors and, more particularly, to the formation of barrier layers in such capacitors to reduce leakage currents.Description of the Related Art[0002]As semiconductor fabrication technologies improve, forming high-density metal-insulator-metal capacitors (MIMCAPs) becomes challenging. MIMCAPs are conventionally formed in between layers of a device, for example using a thin stack that covers a large area.[0003]To obtain a sufficiently high capacitance density (i.e., capacitance per unit area), three-dimensional capacitor structures are employed with high-k dielectric insulators. For example, three-electrode stacked capacitors have been implemented to address the challenge of providing high capacitance for decoupling capacitors.[0004]However, a large percentage of the chip area (e.g., up to about 95%) may need to be covered with such decoupling capacitors to achieve the total capa...

AI Technical Summary

Benefits of technology

This method significantly reduces leakage currents by forming barrier layers that increase the barrier height between electrodes and the conduction band of the insulator layer, enhancing capacitor performance and maintaining the resistivity of the metal layers.

Problems solved by technology

As semiconductor fabrication technologies improve, forming high-density metal-insulator-metal capacitors (MIMCAPs) becomes challenging.

Such high areas mean that leakage current must be reduced as much as possible, otherwise the power loss due to leakage currents will be substantial.

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