METHOD OF FABRICATING METAL-INSULATOR-METAL (MIM) CAPACITOR WITHIN TOPMOST THICK INTER-METAL DIELECTRIC LAYERS

摘要

Embodiments of MIM capacitors may be embedded into a thick IMD layer with enough thickness (e.g., 10 KŘ30 KÅ) to get high capacitance, which may be on top of a thinner IMD layer. MIM capacitors may be formed among three adjacent metal layers which have two thick IMD layers separating the three adjacent metal layers. Materials such as TaN or TiN are used as bottom/top electrodes & Cu barrier. The metal layer above the thick IMD layer may act as the top electrode connection. The metal layer under the thick IMD layer may act as the bottom electrode connection. The capacitor may be of different shapes such as cylindrical shape, or a concave shape. Many kinds of materials (Si3N4, ZrO2, HfO2, BST . . . etc.) can be used as the dielectric material. The MIM capacitors are formed by one or two extra masks while forming other non-capacitor logic of the circuit.

主权项

1. A metal-insulator-metal (MIM) capacitor within an integrated circuit (IC) comprising:
a bottom plate in a first metal layer of the circuit on top of a first inter-metal dielectric (IMD) layer with a first thickness; a bottom electrode, formed in a second IMD layer with a second thickness greater than the first thickness, and formed on top of the first metal layer; a dielectric layer adjacent to the bottom electrode within the second IMD layer; a top electrode adjacent to the dielectric layer within the second IMD layer; a top plate in a second metal layer connected to the top electrode; and a third metal layer disposed between the first metal layer and the second metal layer.