Electrically rewritable non-volatile memory element
View Patent ↗A non-volatile semiconductor memory device includes a plurality of lower electrodes arranged in a matrix manner, a plurality of recording layer patterns, each being arranged on the lower electrode, that contain a phase change material, and an interlayer insulation film that is provided between the lower electrode and the recording layer pattern and that has a plurality of apertures for exposing one portion of the lower electrode. The lower electrode and the recording layer pattern are connected in each aperture. The apertures extend in the X direction in parallel to one another. The recording layer patterns extend in the Y direction in parallel to one another. Thus the aperture can be formed with higher accuracy as compared to forming an independent aperture. Accordingly, high heating efficiency can be obtained while effectively preventing occurrence of poor connection or the like.
1. A non-volatile semiconductor memory device, comprising:
a plurality of lower electrodes arranged in a matrix form having a plurality of rows and columns;
an interlayer insulating film covering each of the lower electrodes;
a plurality of apertures selectively formed in the interlayer insulating film, the apertures being arranged separately from one another and in parallel to one another in a column direction, each of the apertures being extended continuously in a row direction to expose respective parts of all the lower electrodes belonging to an associated one of the rows of the matrix; and
a plurality of recording layers selectively formed over the interlayer insulating film and each containing a phase change material, the recording layers being arranged separately from one another and in parallel to one another in a row direction, each of the recording layers being extended continuously in a column direction to be in contact through the corresponding ones of the apertures with the respective parts of all the lower electrodes belonging to an associated one of the columns of the matrix.
2. The device as claimed in claim 1 , wherein each of the lower electrodes has an upper surface in a ring-shape so that two portions of the upper surface being exposed through an associated one of the apertures, one of the two portions being in contact with an associated one of the recording layers with keeping the other of the two portions apart from the associated one of the recording layers.
3. The device as claimed in claim 1 , wherein each of the lower electrodes has an upper surface in a ring-shape so that the part exposed through an associated one of the apertures includes two portions each including a corner of the ring-shape, one of the two portions being in contact with an associated one of the recording layers with keeping the other of the two portions apart from the associated one of the recording layers.
4. The device as claimed in claim 2 , further comprising a plurality of upper electrodes each formed along an associated one of the recording layers in contact therewith.
5. The device as claimed in claim 3 , further comprising a plurality of upper electrodes each formed along an associated one of the recording layers in contact therewith.
6. The device as claimed in claim 2 , further comprising a plurality of memory cell transistors each having source and drain regions, one of the source and drain regions being electrically connected to an associated one of the lower electrodes.
7. The device as claimed in claim 3 , further comprising a plurality of memory cell transistors each having source and drain regions, one of the source and drain regions being electrically connected to an associated one of the lower electrodes.