Method of nanometer lithography
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorDavid S. Y. Hsu
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Abstract
Nanometer thick vertical metallic structures are fabricated on a substrate by depositing a metallic layer on a substrate surface on which one or more buttresses are formed, etching the metallic layer to expose the horizontal surfaces of the substrate and the buttresses, and etching the substrate to remove the buttresses, thereby producing vertical structures on the substrate. The metallic layer is formed by thermal decomposition of a volatile metal-containing precursor gas in the presence of a carrier gas at low pressure, unlike that in conventional CVD reactors. The metallic layer thus formed has a grain size which is fraction of the thickness of the vertical structure.
Claims21
A method for fabricating a vertical metallic structure having nanometer linewidths on a substrate, comprising the steps of:
- providing a substrate having at least one buttress on a first horizontal surface, said buttress having horizontal and vertical surfaces;
- depositing a metallic layer formed by thermal decomposition of a volatile metal-containing precursor gas, selected from the group consisting of metal carbonyls and molecules including a metal coordination compound including PF.sub.3 ligands and a metal, in a gaseous mixture consisting essentially of said precursor gas and a carrier gas on said horizontal and vertical surfaces of said buttress and on said substrate horizontal first surface, said precursor gas having a partial pressure of less than 10.sup.-5 Torr and said carrier gas having a partial pressure of less than 10.sup.-4 Torr, said substrate being at a temperature of about 230.degree. C. to about 350.degree. C. during said deposition;
- removing said metallic layer from said horizontal surface of said buttress and said substrate horizontal first surface;
- and
- etching said substrate so as to remove said buttress and leave said metallic layer deposited on said vertical surface of said buttress.
A method for fabricating a vertical metallic structure having nanometer linewidths on a substrate, comprising the steps of:
- providing a substrate having a horizontal first surface and having at least one buttress deposited on said first substrate surface, said buttress having horizontal and vertical surfaces;
- depositing a metallic layer formed by the thermal decomposition of a Pt(PF.sub.3).sub.4 precursor gas and hydrogen carrier gas on said horizontal and vertical surfaces of said buttress and on said first substrate surface, said precursor gas having a partial pressure of less than 10.sup.-5 Torr and said hydrogen gas having a partial pressure of less than 10.sup.-4 Torr, said substrate being at a temperature of about 230.degree. C. to about 350.degree. C. during said deposition;
- removing said metallic layer from said horizontal surface of said buttress and said first substrate surface so as to retain a portion of said metallic layer formed on said vertical surfaces of said buttress;
- and
- etching said substrate so as to remove said buttress and leave said portion of said metallic layer deposited on said vertical surface of said buttress.
A method for fabricating a structure, including at least one vertical surface and at least one horizontal surface, on a substrate, said structure having a metal layer of less than 0.1 micron thickness thereon, comprising the steps of:
- providing a substrate having at least one structure with at least one horizontal surface and at least one vertical surface;
- depositing a metallic layer of less than 0.1 micron thickness, by thermal decomposition of a volatile metal-containing precursor gas, selected from the group consisting of metal carbonyls and molecules including a metal coordination compound including PF.sub.3 ligands and a metal, in a gaseous mixture consisting essentially of said precursor gas and a carrier gas, on said at least one horizontal surface and said at least one vertical surface, said precursor gas having a partial pressure of less than 10.sup.-5 Torr and said carrier gas having a partial pressure of less than 10.sup.-4 Torr, said substrate being at a temperature of about 230.degree. C. to about 350.degree. C. during said deposition.
Dependencies are inferred from the claim text.