Glycol-based method for forming a thin-film nanoporous dielectric

A method for forming a thin film nanoporous dielectric on a semiconductor substrate, the method comprising the steps of:

• a) providing a semiconductor substrate;
• b) depositing an aerogel precursor sol upon said substrate;
• wherein said aerogel precursor sol comprises
• an aerogel precursor reactant selected from the group consisting of metal alkoxides, at least partially hydrolyzed metal alkoxides, particulate metal oxides, and combinations thereof, and
• a first solvent selected from the group consisting of ethylene glycol, 1,4-butylene glycol, 1,5-pentanediol, and combinations thereof;
• wherein,
• the molar ratio of said first solvent molecules to the metal atoms in said reactant is at least 1:16
• c) allowing said deposited sol to create a gel, wherein said gel comprises a porous solid and a pore fluid;
• and
• d) forming a dry, nanoporous dielectric by removing said pore fluid without substantially collapsing said porous solid.

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

• the method comprising the steps of:
• a) providing a semiconductor substrate having a first surface;
• b) depositing an aerogel precursor sol upon said first surface of said substrate;
• wherein
• said aerogel precursor sol comprises an aerogel precursor reactant selected from the group consisting of metal alkoxides, particulate metal oxides, and combinations thereof,
• a first solvent selected from the group consisting of ethylene glycol, 1,4-butylene glycol, 1,5-pentanediol, and combinations thereof, and a second solvent;
• wherein,
• the molar ratio of said first solvent to the metal atoms in said reactant is at least 1:16
• c) evaporating at least a portion of said second solvent from said deposited sol;
• d) allowing said deposited sol to create a gel;
• wherein
• said gel comprises a porous solid and a pore fluid;
• and
• said allowing is performed in a gelation atmosphere and the evaporation rate of said first solvent in said gelation atmosphere is no greater than 10 angstroms per second;
• e) removing said pore fluid without substantially collapsing said porous solid, thereby forming a dry, porous dielectric.

A method for forming a thermal insulator on a semiconductor substrate, the method comprising the steps of:

• a) providing a semiconductor substrate;
• b) depositing an aerogel precursor sol upon said substrate;
• wherein said aerogel precursor sol comprises
• a metal-based aerogel precursor reactant, and
• a first solvent selected from the group consisting of ethylene glycol, 1,4-butylene glycol, 1,5-pentanediol, and combinations thereof;
• wherein,
• the molar ratio of said first solvent molecules to the metal atoms in said reactant is at least 1:16
• c) allowing said deposited sol to create a gel, wherein said gel comprises a porous solid and a pore fluid;
• and
• d) forming a dry, thermal insulator by removing said pore fluid.