Method for reducing stress in porous dielectric films

摘要

The present invention addresses provides improved methods of preparing a low-k dielectric material on a substrate. The methods involve multi-step ultraviolet curing processes in which UV intensity, wafer substrate temperature and other conditions may be independently modulated at each step. In certain embodiments, a film containing a structure former and a porogen is exposed to UV radiation in a first step to facilitate removal of the porogen and create a porous dielectric film. In a second step, the film is exposed to UV radiation to increase crosslinking within the porous film. In certain embodiments, the curing takes place in a multi-station UV chamber wherein UV intensity and substrate temperature may be independently controlled at each station.

主权项

1. A method of preparing a porous low-k dielectric material on a substrate, the method comprising:
(a) providing a substrate having a precursor film thereon, the precursor film comprising a porogen and a structure former, wherein the precursor film is formed on the substrate through a vapor deposition method; (b) exposing the precursor film to ultraviolet radiation at a first UV power, wherein the ultraviolet radiation at the first UV power preferentially acts to perform porogen removal over cross-linking and thereby create voids within the dielectric material to form the porous low-k dielectric material; and (c) exposing the dielectric material to ultraviolet radiation at a second UV bower to increase cross-linking within the dielectric material, wherein the second UV power is greater than the first UV power.