Semiconductor memory device and manufacturing method of the same
AssigneeNational Institute of Advanced Industrial Science and Technology
InventorsTakahiro Morikawa, Toshimichi Shintani
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Abstract
A technique capable of improving performances of a semiconductor memory device provided with a recording film having a super lattice structure is provided. The semiconductor memory device records information by changing an electric resistance of a recording film by use of a change in an atomic arrangement of the recording film. Moreover, the recording film is provided with a stacked layer portion in which a first crystal layer and a second crystal layer made of chalcogen compounds having respectively different compositions are stacked, an orientation layer that enhances an orientation of the stacked layer portion, and an adhesive layer that improves the flatness of the orientation layer.
Claims13
A semiconductor memory device which records information by changing an electric resistance of a recording film by use of a change in an atomic arrangement of the recording film, the recording film comprising:
- a first base layer formed on a substrate;
- a second base layer formed on the first base layer;
- and
- a stacked layer portion formed by sequentially stacking a first crystal layer made of a first chalcogen compound and a second crystal layer made of a second chalcogen compound having a composition different from that of the first chalcogen compound on the second base layer,
- wherein the second base layer improves an orientation of the stacked layer portion, and
- the first base layer prevents aggregation of the second base layer.
A semiconductor memory device which records information by changing an electric resistance of a recording film by use of a change in an atomic arrangement of the recording film, the recording film comprising:
- a first base layer formed on a substrate;
- a second base layer formed on the first base layer;
- and
- a stacked layer portion formed by sequentially stacking a first crystal layer made of a first chalcogen compound and a second crystal layer made of a second chalcogen compound having a composition different from that of the first chalcogen compound on the second base layer,
- wherein the second base layer improves an orientation of the stacked layer portion, and
- the first base layer is made of a nitride or an oxide of a transition metal.
A manufacturing method of a semiconductor memory device comprising:
- a first step of forming a first base layer made of a nitride or an oxide of a transition metal on a substrate;
- a second step of forming, on the first base layer, a second base layer that has a hexagonal crystal structure whose c-axis is oriented perpendicularly to a surface of the first base layer;
- a third step of, after the second step, forming a first crystal layer made of a first chalcogen compound on the substrate;
- and
- a fourth step of, after the second step, forming a second crystal layer made of a second chalcogen compound having a composition different from that of the first chalcogen compound on the substrate.
Dependencies are inferred from the claim text.