Phase change memory cell with heater and method therefor
View Patent ↗A method for forming a phase change memory cell (PCM) includes forming a heater for the phase change memory and forming a phase change structrure electrically coupled to the heater. The forming a heater includes siliciding a material including silicon to form a silicide structure, wherein the heater includes at least a portion of the silicide structure. The phase change structure exhibits a first resistive value when in a first phase state and exhibits a second resistive value when in a second phase state. The silicide structure produces heat when current flows through the silicide structure for changing the phase state of the phase change structure.
1. A circuit including a phase change memory device, the circuit comprising:
a phase change memory cell, the phase change memory cell including:
a phase change memory structure, the phase change memory structure including material over an insulating layer, the material exhibiting a first resistive value when in a first phase state and exhibiting a second resistive value when in a second phase state;
a heater electrically coupled to the phase change memory structure, wherein the heater includes a silicide structure for producing heat when current flows through the silicide structure for changing a phase state of the phase change memory structure,
wherein:
the silicide structure having a bottom surface directly on the insulating layer and a top surface above the bottom surface that comprises a first silicided region narrowing to a first pointed edge extending from the bottom surface directly on the insulating layer to the top surface and a second silicided region narrowing to a second pointed edge extending from the bottom surface directly on the insulating layer to the top surface, wherein the first and second pointed edges are in parallel and are vertical with respect to the bottom surface;
the first pointed edge is separated from the second pointed edge;
the first pointed edge and the second pointed edge contact the phase change memory structure; and
current flows from the first pointed edge to the second pointed edge for producing the heat.
2. The circuit of claim 1 further comprising:
a structure including silicon, the silicide structure formed on the structure including silicon.
3. The circuit of claim 2 further comprising;
wherein the material has a first portion covering the first pointed edge, a second portion covering the second pointed edge, and third portion directly on the insulating layer connecting the first portion and the second portion.
4. The circuit of claim 2 further comprising:
a transistor, the transistor including a channel region in the structure including silicon.
5. The circuit of claim 1 further comprising:
a transistor;
a contact, electrically coupled to an electrode structure of the transistor, wherein the contact is electrically in contact with a silicide electrode structure of the transistor that includes a metal, wherein the silicide structure of the heater includes the same metal.
6. The circuit or claim 1 wherein the heater includes a metal spacer located between the silicide structure and the phase change memory structure, the metal spacer producing heat for changing the phase state of the phase change memory structure when current flows through the metal spacer.
7. The circuit of claim 1 wherein the silicide structure includes a portion located on a sidewall of a structure including silicon.
8. A circuit including a phase change memory device, the circuit comprising:
a phase change memory cell, the phase change memory cell including:
a phase change memory structure, the phase change memory structure over an insulating layer, the phase change memory structure including material exhibiting a first resistive value when in a first phase state and exhibiting a second resistive value when in a second phase state; and
a heater electrically coupled to the phase change memory structure, wherein the heater includes a silicide structure having a bottom surface directly on the insulating layer and a top surface above the bottom surface for producing heat when current flows through the silicide structure for changing a phase state of the phase change memory structure,
wherein:
the silicide structure comprises a first silicided region narrowing to a first pointed edge running vertically from the bottom surface directly on the insulating layer to the top surface and a second silicided region narrowing to a second pointed edge running vertically from the bottom surface directly on the insulating layer to the top surface;
the first pointed edge is separated from the second pointed edge;
the heater is directly connected to the phase change memory through the first pointed edge and the second pointed edge; and
current flows from the first pointed edge to the second pointed edge for producing the heat.
9. The circuit of claim 8 , wherein the heater further comprises a first metallic sidewall spacer on the first pointed edge and a second metallic sidewall spacer on the second pointed edge.
10. The circuit of claim 9 , wherein the first metallic sidewall spacer is in direct contact with a first side of the phase change memory structure and the second metallic sidewall spacer is in direct contact with a second side of the phase change memory structure.
11. The circuit of claim 10 , wherein the first and second silicided regions comprise nickel.
12. The circuit of claim 11 , wherein the first and second metallic sidewalls comprise one of a group consisting of titanium and tantalum.
13. The circuit of claim 12 , wherein the first silicided region is separated from the phase change memory structure by the first metallic sidewall spacer and the second silicided region is separated from the phase change memory structure by the second metallic sidewall spacer.
14. The circuit of claim 8 , wherein the first and second silicided regions comprise cobalt.
15. The circuit of claim 14 , wherein the first pointed edge and the second pointed edge are covered by the material.