Semi-conductor chip test probe and process for manufacturing the probe

Claim 1

A probe structure for testing semi-conductor chips, comprising: a substrate; an oxide film for covering over said substrate and at least a part of some cavities, said cavities being formed in said substrate; an organic film formed on and extending over said oxide film; a plurality of conductive projections, formed on said organic film; each of said projections being aligned, with a respective one of said cavities, and positionally matched with a respective I/O pad on a semi-conductor chip to be probed; and conductive leads connected with said projections.

Claim 7

A method of forming a microprobe comprising the steps of: selecting a substrate having first and second surfaces; forming a substantially uniform elastic layer, on said first surface of the substrate; opening a small hole in said elastic layer; exposing said substrate, coated with said elastic layer, to a plasma etching process selected to etch the underlying substrate selectively and isotopically, to form a cavity under each such opening with a diameter significantly greater than the diameter of the opening in said elastic layer; forming a plurality of metal leads on the elastic layer; and forming a metal electrode in contact with said leads over the opening formed in the elastic layer.

Claim 8

A method of forming a microprobe comprising the steps of: selecting a substrate having first and second surfaces; forming a substantially uniform elastic layer, on said first surface of the substrate; opening a small hole in said elastic layer; exposing said substrate, coated with said elastic layer, to a plasma etching process selected to etch the underlying substrate selectively and isotopically, to form a cavity under each such opening with a diameter significantly greater than the diameter of the opening in said elastic layer; forming a plurality of metal leads on the elastic layer; and forming a metal electrode in contact with said leads over the opening formed in the elastic layer.

Claim 10

A method of forming a microprobe comprising the steps of: selecting a substrate having first and second surfaces; forming a substantially uniform polyimide layer, several micrometers in thickness, on said first surface of the substrate by applying a high viscosity, liquid polyimide on the surface and spinning the substrate; baking said polyimide to harden said layer; opening a small hole in said hardened layer; exposing said substrate, coated with said hardened polyimide, to a plasma etching process selected to etch the underlying substrate selectively and isotopically, to form a cavity under each such opening with a diameter significantly greater than the diameter of the opening in said polyimide layer; forming a plurality of metal leads on the polyimide layer by; depositing a layer of the selected metal over the surface of the polyimide layer; coating the deposited metal layer with a layer of a photoresist; patterning said photoresist layer to establish the configuration or pattern of each of said leads; defining said leads in said metal layer by etching said metal layer wherein one end of each respective lead terminates on the polyimide layer adjacent a respective hole formed therein; removing the remainder of the photoresist; forming a second layer of photoresist over said leads and said polyimide layer; exposing and developing said second photoresist layer to create a plurality of openings therein each off which is coaxial with a respective opening in said polyimide layer and extending over the end of the respective lead adjacent the respective opening in the polyimide layer; forming a generally hemispherical metal electrode in the opening formed in this second photoresist layer, by electroplating a highly conductive, easily formed metal therein; and removing the second photoresist layer.

Claim 11

A method of forming a microprobe comprising the steps of: selecting a substrate having first and second surfaces; forming a substantially uniform polyimide layer, several micrometers in thickness, on said first surface of the substrate by applying a high viscosity, liquid polyimide on the surface and spinning the substrate; baking said polyimide to harden said layer; opening a small hole in said hardened layer; exposing said substrate, coated with said hardened polyimide, to a plasma etching process selected to etch the underlying substrate selectively and isotopically, to form a cavity under each such opening with a diameter significantly greater than the diameter of the opening in said polyimide layer; forming a plurality of metal leads on the polyimide layer by; depositing a layer of the selected metal over the surface of the polyimide layer; coating the deposited metal layer with a layer of a photoresist; patterning said photoresist layer to establish the configuration or pattern of each of said leads; defining said leads in said metal layer by etching said metal layer wherein one end of each respective lead terminates on the polyimide layer adjacent a respective hole formed therein; removing the remainder of the photoresist; forming a second layer of photoresist over said leads and said polyimide layer; exposing and developing said second photoresist layer to create a plurality of openings therein each off which is coaxial with a respective opening in said polyimide layer and extending over the end of the respective lead adjacent the respective opening in the polyimide layer; forming a generally hemispherical metal electrode in the opening formed in this second photoresist layer, by electroplating a highly conductive, easily formed metal therein; and removing the second photoresist layer.

Claim 12

A method of forming a microprobe comprising the steps of: selecting a substrate having first and second surfaces; forming substantially circular polyimide dots, several micrometers in thickness, at predetermined positions on said first surface of the substrate; exposing said first surface of said substrate, coated with said dots thereon, to a plasma etching process selected to etch the underlying substrate selectively and isotopically, to form a pinnacles under each such dot, each pinnacle having a diameter less than the dot of said photoresist; removing the photoresist dot; replicating said pinnacles in an oxide layer by oxidizing the surface of the substrate to from an oxide layer thereon; overcoating said oxide layer with a photoresist layer; exposing and developing said photoresist layer to expose a C shaped section of the surface of said oxide layer around each pinnacle on said surface; etching the exposed portion of said oxide layer to expose a C shaped section of said substrate surface; selectively and isotopically etching said exposed substrate surface to form a cavity therein which extends under a cantilevered tongue of oxide carrying replicated pinnacle; and forming metal leads on each said tongue; said metal lead on each tongue extending the length of the tongue and overlying said pinnacle.

Claim 13

A method of forming a microprobe comprising the steps of: selecting a substrate having first and second surfaces; forming substantially circular polyimide dots, several micrometers in thickness, at predetermined positions on said first surface of the substrate; exposing said first surface of said substrate, coated with said dots thereon, to a plasma etching process selected to etch the underlying substrate selectively and isotopically, to form a pinnacles under each such dot, each pinnacle having a diameter less than the dot of said photoresist; removing the photoresist dot; replicating said pinnacles in an oxide layer by oxidizing the surface of the substrate to from an oxide layer thereon; overcoating said oxide layer with a photoresist layer; exposing and developing said photoresist layer to expose a C shaped section of the surface of said oxide layer around each pinnacle on said surface; etching the exposed portion of said oxide layer to expose a C shaped section of said substrate surface; selectively and isotopically etching said exposed substrate surface to form a cavity therein which extends under a cantilevered tongue of oxide carrying replicated pinnacle; and forming metal leads on each said tongue; said metal lead on each tongue extending the length of the tongue and overlying said pinnacle.