Method of making a semiconductor device using a low dielectric constant material

A method of forming a porous dielectric on a semiconductor device comprising:

• (a) providing a first conductor and a horizontally adjacent second conductor, formed on a substrate wherein a gap is formed between said first and said second conductors;
• (b) providing a solution capable of forming a wet gel;
• (c) coating said substrate with said solution such that the gap between said first and second conductors is filled substantially with said solution;
• (d) gelling said solution to form a wet gel on said substrate, said wet gel containing pores arranged in an open-pored structure:
• (e) replacing at least 15% of reactive groups on the surface of said pores with substantially stable surface groups;
• and
• (f) drying said wet gel to form a porous dielectric layer, at one or more sub-critical pressures, said porous dielectric having a dielectric constant less than 3.0 and a pore diameter of less than 80 nm, whereby the capacitive coupling between conductors on the same level is substantially reduced compared to a solid silicon dioxide dielectric, and whereby unwanted condensation reactions and densification of said wet gel during said drying step are controlled.

A method of forming a porous dielectric on a semiconductor device comprising:

• (a) providing a semiconductor substrate;
• (b) preparing a solution capable of forming a wet gel;
• (c) coating said substrate with a film of said solution, said film having an average thickness between 0.1 microns and 2 microns;
• (d) gelling said film to form a wet gel on said substrate, said wet gel containing pores arranged in an open-pored structure;
• (e) performing a solvent exchange on said wet gel to remove substantially all water contained in said gel;
• (f) reacting said wet gel with a surface modification agent to replace at least 15% of reactive groups on the surface of said pores with substantially stable surface groups;
• and
• (g) evaporating said solvent from said wet gel at approximately atmospheric pressure to from a porous dielectric layer, whereby unwanted condensation reactions and the shrinkage of said wet gel during said drying step are controlled.