Patent ID: 8637412
Filing Date: 2014-01-28
Classification: C08J,H01L

Abstract:
1. A method for forming an ultra low k dielectric layer comprising: selecting a plasma enhanced chemical vapor deposition chamber; placing a substrate in said chamber; introducing a first organo-silicon precursor including an organic porogen into said chamber; heating said substrate to a temperature in the range from 200° C. to 350° C.; controlling the amount of an oxidant gas in said chamber; forming a deposited layer by applying high frequency radio frequency power in said chamber to initiate a plasma and polymerization of said first organo-silicon precursor and retain at least a fraction of said organic porogen in said deposited layer; after a period of time terminating said plasma in said chamber; and applying to said deposited layer an energy post treatment selected from the group consisting of thermal anneal, ultra violet (UV) radiation, and electron beam irradiation to drive out said organic porogen and increase the porosity in said deposited layer to at least five percent; wherein prior to introducing said first organo-silicon precursor introducing a flow of a silicon oxide precursor alone followed by introducing an increasing flow of a second organo-silicon precursor while reducing said flow of said silicon oxide precursor to form a graded layer where the content of C increases with thickness.