Methods of forming perpendicular magnetic tunnel junction memory cells having vertical channels
A method of forming a transistor, according to one embodiment, includes: forming an doped material, depositing an oxide layer on the doped material, depositing a conducting layer on the oxide layer, patterning the conducting layer to form at least two word lines, depositing a nitride layer above the at least two word lines, defining at least two hole regions, at each of the defined hole regions, etching down to the doped material through each of the respective word lines, thereby creating at least two holes, depositing a gate dielectric layer on the nitride layer and in the at least two holes, depositing a protective layer on the gate dielectric layer, etching in each of the at least two holes down to the doped material, and removing a remainder of the protective layer.
1. A magnetic memory array comprising:
a cylindrical semiconductor channel structure having a first end, a second end opposite the first end and an outer side extending from the first end to the second end;
an electrically conductive word line surrounding at least a portion of the side of the semiconductor channel structure;
a gate dielectric layer disposed between the electrically conductive word line and the semiconductor channel structure; and
a magnetic memory element, electrically connected with first end of the semiconductor channel structure, the magnetic memory element being a perpendicular magnetic tunnel junction element that further comprises:
a magnetic reference layer;
a magnetic free layer; and
a non-magnetic barrier layer disposed between the magnetic reference layer and the magnetic free layer; and
a perpendicular magnetic anisotropy enhancement layer, comprising one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof disposed directly on the magnetic free layer.
2. The magnetic memory array as in claim 1 , wherein the magnetic anisotropy enhancement layer is a buffer layer formed beneath the magnetic reference layer, the buffer layer further comprising one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof.
3. The magnetic memory array as in claim 1 , wherein the magnetic anisotropy enhancement layer is a cap layer formed over and contacting the magnetic free layer, the cap layer comprising one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof.
4. The magnetic memory element as in claim 1 , wherein the magnetic anisotropy enhancement layer is a buffer layer formed beneath the reference layer, the buffer layer comprising one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof; and further comprising a second magnetic anisotropy enhancement layer that is a cap layer formed over and in contact with the magnetic free layer, the cap layer further comprising one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof.
5. The magnetic memory element as in claim 1 , wherein the barrier layer comprises magnesium oxide and wherein the magnetic free layer is sandwiched between the barrier layer and the perpendicular magnetic anisotropy enhancement layer.
6. The magnetic memory array as in claim 1 , wherein the barrier layer comprises magnesium oxide and wherein the magnetic reference layer is located between the barrier layer and the perpendicular magnetic anisotropy enhancement layer.
7. The magnetic memory array as in claim 1 , wherein:
the barrier layer comprises magnesium oxide;
the magnetic free layer is sandwiched between the buffer layer and a cap layer that comprises one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof; and
the magnetic reference layer is located between the barrier layer and a buffer layer that comprises one or more of one or more of: Ta, Cr, W, V, Mo, Pt, Ru, Pd, Cu, Ag, Ru or alloys thereof.
8. The magnetic memory array as in claim 1 , wherein the cylindrical semiconductor channel structure comprises Si.
9. The magnetic memory array as in claim 1 , wherein the cylindrical semiconductor channel structure comprises monocrystalline Si.
10. The magnetic memory array as in claim 1 , wherein the gate dielectric contacts the outer side of the cylindrical semiconductor channel structure.
11. The magnetic memory array as in claim 1 , wherein the cylindrical semiconductor channel structure is formed over an n-doped semiconductor substrate.
12. The magnetic memory array as in claim 11 , wherein the cylindrical semiconductor channel structure comprises mono-crystalline Si.