Fin selector with gated RRAM
View Patent ↗A method of fabricating a fin selector with a gated RRAM and the resulting device are disclosed. Embodiments include forming a bottom electrode layer and a hardmask on a semiconductor substrate; etching the hardmask, bottom electrode layer, and semiconductor substrate to form a fin-like structure; forming first and second dummy gate stacks on first and second side surfaces of the fin-like structure, respectively; forming spacers on vertical surfaces of the first and second dummy gate stacks; forming an ILD surrounding the spacers; removing the first and second dummy gate stacks, forming first and second cavities on first and second sides of the fin-like structure; forming an RRAM layer on the first and second side surfaces of the fin-like structure in the first and second cavities, respectively; and filling each of the first and second cavities with a top electrode.
1. A device comprising:
a semiconductor substrate;
a bottom electrode layer on a semiconductor substrate;
a hardmask on the bottom electrode layer, the semiconductor substrate, bottom electrode layer, and hardmask forming a fin-like structure;
first and second resistive random access memory (RRAM) layers on the first and second side surfaces of the fin-like structure, respectively;
first and second top electrodes on the first and second RRAM layers, respectively;
spacers on vertical surfaces of the first and second top electrodes; and
an interlayer dielectric (ILD) surrounding the spacers.
2. The device according to claim 1 , wherein the RRAM layers comprise a transition metal.
3. The device according to claim 1 , wherein the bottom electrode is formed to a thickness of 3 to 20 nanometers and comprises titanium nitride (TiN), tantalum oxide (TaN), tungsten (W), platinum (Pt), or a multilayer with an oxygen vacancies layer.
4. The device according to claim 1 , further comprising an oxide on the first and second sides of the substrate of the fin-like structure, and an RRAM layer on a top surface of the oxide.
5. The device according to claim 1 , comprising:
an RRAM layer on a top surface of the hardmask of the fin-like structure; and
a top electrode layer over the RRAM layer and the top electrodes.
6. The device according to claim 1 , further comprising a spacer on each of the first and second side surfaces of the semiconductor substrate of the fin-like structure, wherein the RRAM layer is formed on each spacer and on the first and second side surfaces of the hardmask and the bottom electrode layer.
7. The device according to claim 1 , further comprising an access gate on each of the first and second sides of the fin-like structure.
8. The device according to claim 7 , wherein the access gates comprise:
a bottom electrode layer and a hardmask on the semiconductor substrate;
an oxide layer on the first and second side surfaces of the fin-like structure; and
a polysilicon gate electrode on each oxide layer.