Diode/superionic conductor/polymer memory structure
View Patent ↗A conjugated polymer layer with a built-in diode is formed by providing a first metal-chalcogenide layer over a bottom electrode. Subsequently, a second metal-chalcogenide layer is provided over and in contact with the first metal-chalcogenide layer. The first metal-chalcogenide layer has a first conductivity type and the second metal-chalcogenide layer has a second conductivity type. The plane of contact between the first and second metal-chalcogenide layers creates the p-n junction of the built-in diode. Then a polymer layer is selectively deposited on the second metal-chalcogenide layer. The second metal-chalcogenide layer provides ions to the polymer layer to change its resistivity. A top electrode is then provided over the polymer layer. An exemplary memory cell may have the following stacked structure: first electrode/n-type semiconductor/p-type semiconductor/conjugated polymer/second electrode.
1. A method of forming a semiconductor device, comprising the steps of:
forming a first electrode;
forming a first metal-chalcogenide layer having a first conductivity type in contact with said first electrode;
forming a second metal-chalcogenide layer having a second conductivity type in contact with said first metal-chalcogenide layer;
forming a polymer memory element in contact with said second metal-chalcogenide layer, wherein said polymer memory element has a convex upper surface; and
forming a second electrode in contact with said polymer memory element.
2. The method of claim 1 , wherein said steps of forming said first metal-chalcogenide layer and forming said second metal-chalcogenide layer include sputtering and etching.
3. The method of claim 1 , wherein said step of forming a polymer memory element includes depositing a material that adheres preferentially to the second metal-chalcogenide layer.
4. The method of claim 3 , wherein said material is a conjugated polymer that changes resistance in response to an applied electric field.
5. The method of claim 4 , wherein said conjugated polymer is selected from the group consisting of polymethylphenylacetylene, copperphtalocyanine, polyparaphenylene, polyphenylenevinylene, polyaniline, polythiophene and polypyrrole.
6. The method of claim 3 , wherein the step of forming a polymer memory element includes locating said semiconductor device within an enclosed chamber with a liquid monomer.