Depositing titanium silicon nitride films for forming phase change memories
View Patent ↗Organometallic precursors may be utilized to form titanium silicon nitride films that act as heaters for phase change memories. By using a combination of TDMAT and TrDMASi, for example in a metal organic chemical vapor deposition chamber, a relatively high percentage of silicon may be achieved in reasonable deposition times, in some embodiments. In one embodiment, two separate bubblers may be utilized to feed the two organometallic compounds in gaseous form to the deposition chamber so that the relative proportions of the precursors can be readily controlled.
1. A method comprising:
forming a heater layer contacting a first conductive material, the heater layer including titanium silicon nitride (TiSiN) generated from tetrakis-(dimethlamino)-titanium (TDMAT) and tris-(dimethlamino)-saline (TrDMASi), the TiSiN of the heater distinct from the first conductive material, wherein a heater formed from the heater layer is L-shaped;
forming a phase change memory material layer over the heater layer; and
forming a second conductive layer over the phase change memory material layer.
2. The method of claim 1 , wherein forming the heater layer comprises, contemporaneously:
vaporizing the TDMAT in a first bubbler; and
vaporizing the TrDMASi in a second bubbler.
3. The method of claim 2 , further comprising controlling a ratio of the TDMAT to the TrDMASi by at least one of:
adjusting a temperature or a pressure of the first bubbler; and
adjusting a temperature or a pressure of the second bubbler.
4. The method of claim 3 , wherein the ratio of the TDMAT to the TrDMASi is approximately one part TDMAT to ten parts TrDMASi.
5. The method of claim 2 , further comprising:
heating the first bubbler to a first temperature; and
heating the second bubbler to a second temperature.
6. The method of claim 5 , wherein the first temperature is approximately equal to the second temperature.
7. The method of claim 5 , wherein the temperature of the first bubbler and the temperature of the second bubbler are each approximately 50 degrees Celsius.
8. The method of claim 1 , wherein a thickness of the heater layer is approximately 50 angstroms.
9. A method comprising:
etching a trench in an oxide layer and a nitride layer, wherein the trench exposes a conductive material;
depositing tetrakis-(dimethlamino)-titanium (TDMAT) and tris-(dimethlamino)-saline (TrDMASi) in the trench to form a titanium silicon nitride (TiSiN) layer, the TiSiN layer contacting the conductive material, wherein the TiSiN layer is distinct from the conductive material; and
removing a portion of the TiSiN layer; wherein a remaining portion of the TiSiN layer is L-shaped.
10. The method of claim 9 , wherein a vertical wall of the trench is aligned with a horizontal center of the conductive material.
11. The method of claim 9 , further comprising masking the remaining portion of the trench prior to removing the portion of the TiSiN layer; wherein removing the portion of the TiSiN layer exposes a portion of the conductive material, wherein a vertical portion of the L-shape of the remaining portion of the TiSiN layer contacts a vertical wall of the trench and a base portion of the L-shape of the remaining portion of the TiSiN layer contacts the conductive material.
12. The method of claim 11 , further comprising forming a phase change memory material layer that contacts the remaining portion of the TiSiN layer at the vertical portion of the L-shape.
13. The method of claim 11 , further comprising forming a phase change memory material layer that contacts the remaining portion of the TiSiN layer at the vertical portion of the L-shape.
14. A method comprising:
forming a heater layer over a conductive material, wherein a heater formed from the heater layer is L-shaped, wherein a material of the heater layer is distinct from the first conductive material; and
forming a phase change memory material layer contacting the heater layer.
15. The method of claim 14 , wherein forming, the heater layer comprises depositing tetrakis-(dimethlamino)-titanium (TDMAT) and tris-(dimethlamino)-saline (TrDMASi) to form, a titanium silicon nitride (TiSiN) layer.
16. The method of claim 14 , wherein the heater layer comprises 10 atomic percent silicon to 20 atomic percent silicon.
17. The method of claim 14 , further comprising forming a select device over the phase change memory material layer.
18. The method of claim 17 , wherein the select device comprises an ovonic threshold switch.
19. The method of claim 14 , wherein forming the phase change memory material layer comprises depositing a chalcogenide alloy material.
20. The method of claim 14 , wherein a resistivity of the conductive material is less than a resistivity of the heater layer.