Interlevel dielectric stack for interconnect structures

摘要

A dielectric stack and method of depositing the stack to a substrate using a single step deposition process. The dielectric stack includes a dense layer and a porous layer of the same elemental compound with different compositional atomic percentage, density, and porosity. The stack enhances mechanical modulus strength and enhances oxidation and copper diffusion barrier properties. The dielectric stack has inorganic or hybrid inorganic-organic random three-dimensional covalent bonding throughout the network, which contain different regions of different chemical compositions such as a cap component adjacent to a low-k component of the same type of material but with higher porosity.

主权项

1. An interconnect structure comprising:
a device level; at least a first wiring level and a second wiring level; at least one via and one conductive line connecting the first wiring level and the second wiring level; and a dielectric stack in at least one of the first and second wiring level comprising: a first layer comprising concentrations of silicon (Si), carbon (C), nitrogen (N) and hydrogen (H) a transition layer comprising a composition of graded nitrogen (N) and graded carbon (C); and a second layer comprising concentrations of silicon (Si), carbon (C), nitrogen (N) and hydrogen (H), wherein the first layer is dense and nitrogen-rich, and the second layer is carbon-rich and is porous.