MTJ bottom metal via in a memory cell and method for producing the same
A method of forming a memory cell with a high aspect ratio metal via formed underneath a metal tunnel junction (MTJ) and the resulting device are provided. Embodiments include a device having a metal via formed underneath a metal tunnel junction (MTJ) in a memory cell, and the metal via has an aspect ratio smaller than 2.
1. A device comprising:
a metal via disposed underneath a metal tunnel junction (MTJ) in a memory cell;
at least two metal interconnecting layers,
wherein a first metal interconnecting layer is disposed over the MTJ, and a second metal interconnecting layer is disposed underneath the metal via, and
wherein the metal via has an aspect ratio smaller than 2, and
wherein the first metal interconnecting layer has a wider pitch than the second metal interconnecting layer.
2. The device according to claim 1 , wherein the device is a magnetic random-access memory (MRAM) device.
3. The device according to claim 1 , wherein the first and second metal interconnecting layers comprise copper (Cu).
4. The device according to claim 1 , wherein the metal via comprises tungsten (W).
5. The device according to claim 1 , wherein the metal via comprises tantalum nitride (TaN) and has a top level smaller than a bottom level.
6. The device according to claim 1 , further comprising: a bottom electrode disposed between the MTJ and the metal via.
7. A method comprising:
forming a metal via in an interlayer dielectric (ILD) in a memory cell;
forming a metal tunnel junction (MTJ) over the metal via, wherein the metal via has an aspect ratio smaller than 2;
forming a first metal interconnecting layer before forming the metal via, wherein the metal via is formed over the first metal interconnecting layer; and
forming a second metal interconnecting layer over the MTJ,
wherein the first metal interconnecting layer has a wider pitch than the second metal interconnecting layer.
8. The method according to claim 7 , wherein the memory cell is formed in a magnetic random-access memory (MRAM) device.
9. The method according to claim 7 , further comprising:
forming a bottom electrode over the metal via, wherein the MTJ is disposed over the bottom electrode.
10. The method according to claim 7 , wherein the metal via comprises tungsten (W).
11. The method according to claim 7 , wherein the metal via comprises tantalum nitride (TaN) and has a top level smaller than a bottom level.