Method for Delineation of Phase Change Memory Cell Via Film Resistivity Modification
AssigneeInternational Business Machines Corporation
InventorsJohn Christopher Arnold, Tricia Breen Carmichael
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Abstract
A PCM cell structure comprises a lower electrode composed of a Phase Change Memory (PCM) layer and a conductive encapsulating upper electrode layer. The PCM is protected from damage by a conductive encapsulating layer. Electrical isolation between adjacent cells is provided by modifying the conductivity of the PCM layer and the conductive encapsulating upper electrode layer subsequent to deposition.
Claims20
A Phase Change Memory (PCM) device comprising:
- a substrate having an upper surface and including a set of electrical via conductors formed therein having exposed top surfaces;
- a PCM material layer formed on said upper surface in electrical contact with said exposed top surfaces of said via conductors;
- an encapsulating layer composed of an electrically conductive material formed on top of said PCM material layer;
- a set of PCM cells formed by portions of said encapsulating layer and portions of said PCM material layer in contact with said top surface of said electrical conductors;
- and
- said PCM cells being separated by high electrical resistance regions of said PCM material layer and high electrical resistance regions of said encapsulating layer.
A Phase Change Memory (PCM) device comprising:
- a dielectric layer having an upper surface;
- a set of electrical via conductors extending through said dielectric layer to said upper surface;
- each of said electrical via conductors having top surfaces;
- a PCM material layer formed on said upper surface in electrical contact with said top surfaces of said via conductors;
- an encapsulating layer composed of an electrically conductive material formed on top of said PCM material layer;
- a set of PCM cells formed by portions of said encapsulating layer and portions of said PCM material layer in contact with said top surface of said via conductors;
- and
- said PCM cells being separated by high electrical resistance regions of said PCM material layer and high electrical resistance regions of said encapsulating layer.
A method for forming a plurality of Phase Change Memory (PCM) cells, said PCM cells in electrical contact with a set of electrical conductors having exposed top surfaces on a substrate with said substrate having an upper surface and with said PCM cells being located in inboard regions above said electrical conductors and said substrate aside from outboard regions comprising:
- forming a bilayer on said upper surface of said substrate, said bilayer comprising a PCM material layer in electrical contact with said top surfaces of said via conductors extending across said inboard regions and said outboard regions and an encapsulating layer composed of an electrically conductive material on top of said PCM material layer extending across said inboard regions and outboard regions;
- implanting ions into said encapsulating layer and said PCM material layer to form high electrical resistance regions of said PCM material layer and high electrical resistance regions of said encapsulating layer, with said PCM cells being formed as separate cells in said inboard regions from portions of said encapsulating layer and portions of said PCM material layer in contact with said top surface of said electrical conductors and forming resistive material from portions of said encapsulating layer and portions of said PCM material layer in said outboard regions.
A method for forming a device with a plurality of Phase Change Memory (PCM) cells in inboard regions separated by resistive material in outboard regions juxtaposed therewith comprising:
- forming in a substrate with a top surface a set of lower electrodes with exposed upper surfaces in said top surface;
- forming a bilayer on said top surface and on said upper surfaces of said lower electrodes, said bilayer comprising a PCM material layer in contact with said upper surfaces of said lower electrodes and a conductive upper electrode layer over said PCM material layer;
- and
- lowering the electrical conductivity of outboard regions of said PCM material layer and lowering the electrical conductivity of outboard regions of said upper electrode aside from said lower electrodes by implantation of ions therein and annealing to modify the material composition of said outboard regions with said inboard regions having been formed as PCM cells separated by said PCM material layer and said upper electrode layer in said outboard regions.
Dependencies are inferred from the claim text.