Low temperature method for fabricating high-aspect ratio vias and devices fabricated by said method
First Claim
1. A process for fabricating a through-wafer via through a semiconductor wafer on which active circuitry has been fabricated, the wafer having a first surface and a second surface, comprising:
- forming a through-wafer via hole into a semiconductor wafer on which active circuitry has been fabricated;
forming an isolation material directly onto the wafer and onto the interior semiconductor walls of said through-wafer via hole, said isolation material being electrically insulating, continuous and substantially conformal;
preparing the isolation material for receiving a conductive material such that the conductive material will react with the isolation material to plate the via; and
depositing conductive material into the via hole over said isolation material such that it is electrically continuous across the length of said via hole, said conductive material deposited by means of an electroless flowing solution plating process.
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Abstract
Embodiments of the present invention are directed to a process for forming small diameter vias at low temperatures. In preferred embodiments, through-substrate vias are fabricated by forming a through-substrate via; and depositing conductive material into the via by means of a flowing solution plating technique, wherein the conductive material releases a gas that pushes the conductive material through the via to facilitate plating the via with the conductive material. In preferred embodiments, the fabrication of the substrate is conducted at low temperatures.
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Citations
20 Claims
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1. A process for fabricating a through-wafer via through a semiconductor wafer on which active circuitry has been fabricated, the wafer having a first surface and a second surface, comprising:
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forming a through-wafer via hole into a semiconductor wafer on which active circuitry has been fabricated; forming an isolation material directly onto the wafer and onto the interior semiconductor walls of said through-wafer via hole, said isolation material being electrically insulating, continuous and substantially conformal; preparing the isolation material for receiving a conductive material such that the conductive material will react with the isolation material to plate the via; and depositing conductive material into the via hole over said isolation material such that it is electrically continuous across the length of said via hole, said conductive material deposited by means of an electroless flowing solution plating process. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A process for fabricating a through-substrate via, the substrate having a first surface and a second surface, comprising:
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forming a through-substrate via hole into the substrate; forming an isolation material onto the substrate and on the interior walls of said via hole, said isolation material being electrically insulating, continuous and substantially conformal; preparing the isolation material for receiving a conductive material; depositing conductive material into the via hole by means of a flowing solution plating technique such that it is electrically continuous across the length of said via hole, and such that the conductive material reacts with the isolation material to plate the via; wherein the isolation material is parylene; and the isolation material is prepared by activating it with a plasma.
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18. A process for fabricating a through-substrate via, the substrate having a first surface and a second surface, comprising:
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forming a through-substrate via hole into the substrate; forming an isolation material onto the substrate and on the interior walls of said via hole, said isolation material being electrically insulating, continuous and substantially conformal; preparing the isolation material for receiving a conductive material; depositing conductive material into the via hole by means of a flowing solution plating technique such that it is electrically continuous across the length of said via hole, and such that the conductive material reacts with the isolation material to plate the via; wherein the isolation material is prepared by activating it with a seed layer which reacts with the conductive material; and wherein the seed layer is applied by; absorbing tin onto the isolation material by bathing the substrate in a solution of stannous chloride and hydrochloric acid; and bathing the substrate in a solution of palladium chloride and hydrochloric acid to deposit palladium on the substrate'"'"'s surface.
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19. A process for fabricating a through-substrate via, the substrate having a first surface and a second surface, comprising:
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forming a through-substrate via hole into the substrate; forming an isolation material onto the substrate and on the interior walls of said via hole, said isolation material being electrically insulating, continuous and substantially conformal; preparing the isolation material for receiving a conductive material; depositing conductive material into the via hole by means of a flowing solution plating technique such that it is electrically continuous across the length of said via hole, and such that the conductive material reacts with the isolation material to plate the via; wherein the isolation material is prepared by activating it with a seed layer which reacts with the conductive material; and wherein the seed layer is applied by; bathing the substrate in a solution containing a metal acetate such that the vias are coated with the metal acetate; heating the solution such that the metal acetate solution forms a thin metal layer on the interior surfaces of the vias.
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20. A process for fabricating a through-wafer via through a semiconductor wafer, said wafer having a first surface and a second surface and having active circuitry fabricated on said first surface, comprising:
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etching a first cavity having a first diameter into the first surface of said wafer; and etching a second cavity having a second diameter into the second surface of said wafer, wherein the first and second cavities form a single continuous aperture through the wafer, thereby forming a through-wafer via hole, said cavities arranged such that said first diameter is less than said second diameter so as to reduce the area of said first surface occupied by said via; depositing an isolation material directly onto the wafer and onto the interior semiconductor walls of said through-wafer via hole, said isolation material being electrically insulating, continuous and substantially conformal; and depositing conductive material into the via hole over said isolation material such that it is electrically continuous across the length of said via hole.
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Specification