Shaping a Phase Change Layer in a Phase Change Memory Cell
A phase change memory cell includes a phase change layer of a phase change material on a semiconductor body. A hard mask structure is formed on the phase change layer and a resist mask is formed on the hard mask structure. A hard mask is formed by shaping the hard mask structure using the resist mask. The phase change layer is shaped using the hard mask. The resist mask is removed before shaping the phase change layer.
1 . A semiconductor structure comprising:
a chalcogenide layer;
a barrier layer covering said chalcogenide; and
a mask layer over said barrier layer.
2 . The structure of claim 1 wherein said barrier layer includes metal.
3 . The structure of claim 2 wherein said metal includes titanium.
4 . The structure of claim 3 wherein said metal includes Ti/TiN.
5 . The structure of claim 4 wherein said barrier layer is around 45 nm.
6 . The structure of claim 1 wherein said barrier layer completely covers said chalcogenide layer.
7 . The structure of claim 1 including a resist mask over said barrier layer.
8 . The structure of claim 1 including a hard mask over said barrier layer.
9 . The structure of claim 8 including a resist mask over said hard mask.
10 . The structure of claim 1 including two separate chalcogenide layers.