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. A method for forming a dielectric stack structure comprising,
introducing in a reactor a first vapor precursor comprising dimethylsilacyclopentane (DMSCP) and a second vapor precursor of at least one of ammonia and nitrogen gas; striking a plasma in the reactor; depositing a first layer of silicon, carbon, nitrogen and hydrogen on a substrate; reducing the flow rate of the second vapor precursor in the reactor; depositing a second layer of silicon, carbon, nitrogen and hydrogen onto the substrate; and introducing a hydrocarbon porogen precursor into the reactor; wherein the first layer is dense and the second layer is porous.