MTJ containing device containing a bottom electrode embedded in diamond-like carbon
A magnetic tunnel junction (MTJ) containing device is provided in which a bottom electrode having a small CD is formed and is located laterally adjacent to diamond like carbon (DLC). DLC replaces a material stack of, from bottom to top, a silicon nitride layer and an organic planarization layer (OPL) which is typically used in providing a conductive structure having a reduced CD. DLC provides a higher etch resistance to IBE than silicon nitride, but DLC can be patterned using conventional etchants. The use of DLC thus reduces the number of processing steps for providing a reduced CD bottom electrode, and also provides a more robust solution to the issue of punch through to an underlying conductive material layer.
1. A magnetic tunnel junction (MTJ) containing device comprising:
a MTJ pillar located on a topmost surface of a bottom electrode, wherein a diamond like carbon (DLC) layer is located laterally adjacent to the bottom electrode; and
a top electrode located on the MTJ pillar.
2. The MTJ containing device of claim 1 , wherein the bottom electrode is located on a topmost surface of an electrically conductive structure that is embedded in an interconnect dielectric material layer.
3. The MTJ containing device of claim 2 , wherein the DLC layer is present on the entirety of the topmost surface of the interconnect dielectric material layer, and wherein a portion of the DLC layer extends onto the topmost surface of the electrically conductive structure.
4. The MTJ containing device of claim 1 , wherein the bottom electrode has a critical dimension from 20 nm to 60 nm.
5. The MTJ containing device of claim 1 , wherein the MTJ pillar comprises a magnetic reference material, a tunnel barrier material, and a magnetic free material, wherein the magnetic reference material forms an interface with the bottom electrode.
6. The MTJ containing device of claim 1 , wherein no resputtered conductive metal particles are present on a sidewall of the MTJ pillar.
7. The MTJ containing device of claim 1 , wherein the bottom electrode has a smaller critical dimension than a critical dimension of the MTJ pillar and the top electrode.
8. The MTJ containing device of claim 7 , wherein a portion of the MTJ pillar directly contacts a topmost surface of the DLC layer.
9. The MTJ containing device of claim 1 , wherein the DLC layer has a recessed region located at a footprint of the MTJ pillar.
10. The MTJ containing device of claim 9 , wherein the recessed region of the DLC layer has a concave surface.