Chalcogenide material, switching device including the chalcogenide material, and memory device including the switching device

A switching device comprising:

• a first electrode layer;
• a second electrode layer facing the first electrode layer;
• and
• a selection layer arranged between the first electrode layer and the second electrode layer, wherein
• the selection layer comprises a chalcogenide material including:
• germanium (Ge);
• arsenic (As);
• sulfur(S) and no silicon (Si);
• selenium (Se);
• and at least one group III metal selected from indium (In), gallium (Ga), and aluminum (Al), and wherein
• a content of Ge is greater than about 10 at % and less than or equal to about 30 at %,
• a content of As is greater than about 30 at % and less than or equal to about 50 at %,
• a content of Se is greater than about 20 at % and less than or equal to about 60 at %,
• a content of S is greater than about 0.5 at % and less than or equal to about 10 at %, and
• a content of the at least one group III metal is greater than about 0.5 at % and less than or equal to about 10 at %.

A memory device comprising:

• a plurality of first electrode lines extending in a first direction and spaced apart from each other;
• a plurality of second electrode lines extending in a second direction crossing the first direction and spaced apart from each other, and
• a plurality of memory cells electrically connected between the plurality of the first electrode lines and the plurality of the second electrode lines, respectively, at intersections of the plurality of the first electrode lines and the plurality of the second electrode lines, wherein
• each of the plurality of memory cells includes a selection layer and a variable resistor layer which are connected in series,
• the selection layer includes a chalcogenide material including:
• germanium (Ge);
• arsenic (As);
• sulfur(S) and no silicon (Si);
• selenium (Se);
• and at least one group III metal selected from indium (In), gallium (Ga), and aluminum (Al), and wherein
• a content of the Ge is greater than about 10 at % and less than or equal to about 30 at %,
• a content of the As is greater than about 30 at % and less than or equal to about 50 at %,
• a content of Se is greater than about 20 at % and less than or equal to about 60 at %,
• a content of S is greater than about 0.5 at % and less than or equal to about 10 at %, and
• a content of the at least one group III metal is greater than about 0.5 at % and less than or equal to about 10 at %.