Low volatility solvent-based method for forming thin film nanoporous aerogels on semiconductor substrates

A method for forming an aerogel, said aerogel having a porosity greater than 60% and an average pore diameter less than 100 nm;

• the method comprising
• supplying a quantity of an aerogel precursor sol;
• gelling said sol to create a gel, wherein said gel comprises a porous solid and a pore fluid;
• removing said pore fluid in an atmosphere, wherein the pressure of said atmosphere is less than the critical pressure of said pore fluid and the temperature of said gel is above the freezing temperature of said pore fluid, thereby forming said aerogel;
• wherein, said method does not comprise the step of adding a surface modification agent to said gel.

A method for forming a nanoporous dielectric on a semiconductor substrate;

• the method comprising the steps of:
• providing a semiconductor substrate having a first surface;
• depositing a thickness of an aerogel precursor sol upon said first surface of said substrate;
• wherein
• said precursor sol is comprised of a reactant, water, a first solvent, and a second solvent;
• wherein said first solvent has a boiling point that is greater than 1400 Celsius;
• wherein said second solvent has a boiling point that is less than the boiling point of the first solvent;
• and
• evaporating at least a portion of said second solvent from said deposited sol;
• allowing said deposited sol to create a gel, wherein said gel comprises a porous solid and a pore fluid and said gelling is performed in an atmosphere;
• removing said pore fluid, thereby forming a dry, porous dielectric.