Forming a phase change memory with an ovonic threshold switch
View Patent ↗A phase change memory may include an ovonic threshold switch formed over an cyanic memory. In one embodiment, the switch includes a chalcogenide layer that overlaps an underlying electrode. Then, edge damage, due to etching the chalcogenide layer, may be isolated to reduce leakage current.
1. A method comprising:
forming an ovonic threshold switch device including a chalcogenide layer and a plug wherein the chalcogenide layer overlaps the plug on two opposed sides;
forming an ovonic memory device directly underlying said ovonic threshold switch device; and
forming said ovonic memory device including a chalcogenide layer which is defined to have a dimension in common with said ovonic threshold switch device.
2. The method of claim 1 including forming a common electrode between said ovonic memory device and ovonic threshold switch device.
3. The method of claim 2 including etching a stack of layers to form said ovonic threshold switch device.
4. The method of claim 3 including etching said common electrode during the same etch used to etch said stack.
5. The method of claim 4 including etching said common electrode using the same mask used to etch said stack.
6. The method of claim 5 including using a hard mask to etch said stack.
7. The method of claim 1 including forming said ovonic memory including a pore having a chalcogenide layer and an electrode in said pore.
8. The method of claim 1 including forming said ovonic memory with a pore filled with an electrode.