BEOL anti-fuse structures for gate last semiconductor devices
An approach is provided for semiconductor devices including an anti-fuse structure. The semiconductor device includes a first metallization layer including a first portion of a first electrode and a second electrode, the second electrode being formed in a substantially axial plane surrounding the first portion of the first electrode, with a dielectric material in between the two electrodes. An ILD is formed over the first metallization layer, a second metallization layer including a second portion of the first electrode is formed over the ILD, and at least one via is formed through the ILD, electrically connecting the first and second portions of the first electrode. Breakdown of the dielectric material is configured to enable an operating current to flow between the second electrode and the first electrode in a programmed state of the anti-fuse structure.
1. A method comprising:
forming a first metallization layer on an insulating layer, the first metallization layer including, in a substantially axial plane, a first portion of a first electrode of an anti-fuse structure; and
a second electrode about the first portion of the first electrode, but separated therefrom;
forming, in the substantially axial plane, a dielectric material surrounding the first portion of the first electrode, between the first portion of the first electrode and the second electrode;
forming an interlayer dielectric (ILD) over the first metallization layer;
forming at least one via through the ILD over the first portion of the first electrode; and
forming a second metallization layer over the ILD, the second metallization layer including a second portion of the first electrode over the at least one via, wherein the at least one via electrically connects the first and second portions of the first electrode,
wherein breakdown of a anti-fuse material is configured to enable an operating current to flow between the second electrode and the first electrode in a programmed state of the anti-fuse structure.
2. The method according to claim 1 , further comprising:
forming the second electrode concentrically about the first portion of the first electrode.
3. The method according to claim 2 , comprising forming the second electrode as a ring or oval around the first portion of the first electrode.
4. The method according to claim 2 , further comprising forming the second electrode separated from the first electrode by 40 nanometers (nm).
5. The method according to claim 1 , comprising forming 1 to 10 vias electrically connecting the first and second portions of the first electrode.
6. The method according to claim 5 , further comprising:
forming a semiconductor layer including at least one integrated circuit (IC) device;
forming the insulating layer over the IC device; and
forming the first and second metallization layers, respectively, above the semiconductor layer.
7. The method according to claim 1 , comprising:
forming the first metallization layer as a metal 1 layer; and
forming the dielectric material of SiCOH having a dielectric constant of 2.7.
8. The method according to claim 1 , comprising:
forming the first metallization layer as one of a metal 2 layer through a metal 8 layer; and
forming the dielectric material of an ultra low-k (ULK) material having a dielectric constant of 2.55.
9. The method according to claim 1 , wherein application of approximately 1 to 2 volts across the anti-fuse material causes the breakdown.