Crystallized silicon vertical diode on BEOL for access device for confined PCM arrays
A method is presented for integrating an electronic component in back end of the line (BEOL) processing. The method includes forming a first electrode over a semiconductor substrate, forming a first electrically conductive material over a portion of the first electrode, forming a second electrically conductive material over the first electrically conductive material, where the first and second electrically conductive materials define a p-n junction, depositing a phase change material over the p-n junction, and forming a second electrode over the phase change material.
1. A method for integrating an electronic component in back end of the line (BEOL) processing, the method comprising:
forming a first electrode over a semiconductor substrate;
forming a first electrically conductive material over a portion of the first electrode;
forming a second electrically conductive material in direct contact with the first electrically conductive material, where the first and second electrically conductive materials define a p-n junction constructed with laser annealing crystallization of the first electrically conductive material and the second electrically conductive material for the BEOL processing, the laser annealing resulting in silicon layers reaching a partial to complete melt to form a polycrystalline material;
forming spacers in direct contact with the p-n junction, the spacers confined entirely between outer sidewalls of the p-n junction;
depositing a phase change material between the spacers and in direct contact with the p-n junction such that the phase change material occupies an entire space defined between the spacers; and
forming a second electrode over the phase change material, the second electrode extending horizontally beyond outer sidewalls of the spacers such that a bottom surface of the second electrode directly contacts a top surface of an inter-layer dielectric (ILD) region.
2. The method of claim 1 , wherein the first electrically conductive material is an n-type poly-silicon layer.
3. The method of claim 2 , wherein second electrically conductive material is a p-type poly-silicon layer.
4. The method of claim 1 , further comprising forming the p-n junction between interlayer dielectric (ILD) regions.
5. The method of claim 1 , wherein no heating electrode is present between the p-n junction and the phase change material.
6. The method of claim 1 , wherein the electronic component is a poly-silicon diode.
7. The method of claim 1 , wherein the p-n junction is an access device and the phase change material is a memory element, the access device combined with the memory element to be positioned between a plurality of first and second electrodes defining a crosspoint array.
8. A method for integrating an electronic component in back end of the line (BEOL) processing, the method comprising:
forming a first electrode over a semiconductor substrate;
forming a first electrically conductive material over the first electrode;
forming an undoped intrinsic semiconductor layer over the first electrically conductive material;
forming a second electrically conductive material over the undoped intrinsic semiconductor layer, where the first electrically conductive material, the undoped intrinsic semiconductor layer, and the second electrically conductive material define a p-i-n junction constructed with laser annealing crystallization of the first electrically conductive material and the second electrically conductive material for the BEOL processing, the laser annealing resulting in silicon layers reaching a partial to complete melt to form a polycrystalline material;
forming spacers in direct contact with the p-i-n junction, the spacers confined entirely between outer sidewalls of the p-i-n junction;
depositing a phase change material between the spacers and in direct contact with the p-i-n junction such that the phase change material occupies an entire space defined between the spacers; and
forming a second electrode over the phase change material, the second electrode extending horizontally beyond outer sidewalls of the spacers such that a bottom surface of the second electrode directly contacts a top surface of an inter-layer dielectric (ILD) region.
9. The method of claim 8 , wherein the first electrically conductive material is an n-type poly-silicon layer.
10. The method of claim 9 , wherein second electrically conductive material is a p-type poly-silicon layer.
11. The method of claim 8 , further comprising forming the p-i-n junction between interlayer dielectric (ILD) regions.
12. The method of claim 8 , wherein no heating electrode is present between the p-i-n junction and the phase change material.
13. The method of claim 8 , wherein the electronic component is a poly-silicon diode.
14. The method of claim 8 , wherein the p-i-n junction is an access device and the phase change material is a memory element, the access device combined with the memory element to be positioned between a plurality of first and second electrodes defining a crosspoint array.
15. A semiconductor structure for integrating an electronic component in back end of the line (BEOL) processing, the structure comprising:
a first electrode disposed over a semiconductor substrate;
a first electrically conductive material disposed over a portion of the first electrode;
a second electrically conductive material disposed in direct contact with the first electrically conductive material, where the first and second electrically conductive materials define a p-n junction constructed with laser annealing crystallization of the first electrically conductive material and the second electrically conductive material for the BEOL processing, the laser annealing resulting in silicon layers reaching a partial to complete melt to form a polycrystalline material;
spacers disposed in direct contact with the p-n junction, the spacers confined entirely between outer sidewalls of the p-n junction;
a phase change material located between the spacers and in direct contact with the p-n junction such that the phase change material occupies an entire space defined between the spacers; and
a second electrode disposed over the phase change material, the second electrode extending horizontally beyond outer sidewalls of the spacers such that a bottom surface of the second electrode directly contacts a top surface of an inter-layer dielectric (ILD) region.
16. The semiconductor structure of claim 15 , wherein the first electrically conductive material is an n-type poly-silicon layer.
17. The semiconductor structure of claim 16 , wherein second electrically conductive material is a p-type poly-silicon layer.
18. The semiconductor structure of claim 15 , wherein the p-n junction is disposed between interlayer dielectric (ILD) regions.
19. The semiconductor structure of claim 15 , wherein no heating electrode is present between the p-n junction and the phase change material.
20. The semiconductor structure of claim 15 , wherein the electronic component is a poly-silicon diode.