Memory first process flow and device
View Patent ↗Semiconductor devices and methods of manufacturing such devices are described herein. According to embodiments, a semiconductor device includes a memory gate disposed in a first region of the semiconductor device. The memory gate may include a first gate conductor layer disposed over a charge trapping dielectric. A select gate may be disposed in the first region of the semiconductor device adjacent to a sidewall of the memory gate. A sidewall dielectric may be disposed between the sidewall of the memory gate and the select gate. Additionally, the device may include a logic gate disposed in a second region of the semiconductor device that comprises the first gate conductor layer.
1. A semiconductor device, comprising:
a memory gate, disposed in a first region of the semiconductor device, wherein the memory gate includes a first gate conductor layer disposed such that it overlaps a charge trapping dielectric;
a first select gate disposed in the first region adjacent to a sidewall of the memory gate;
a second select gate disposed adjacent to the first select gate in the first region such that the first select gate is disposed between the memory gate and the second select gate;
a sidewall dielectric disposed between the sidewall of the memory gate and the first select gate; and
a dielectric layer disposed beneath the first select gate and the second select gate, wherein the dielectric layer is disposed such that it is separated from the charge trapping layer and the memory gate by the sidewall dielectric.
2. The device of claim 1 , wherein the first select gate comprises a second gate conductor layer.
3. The device of 1 , further comprising a second logic gate disposed in a third region of the semiconductor device.
4. The device of 3 , wherein the second logic gate comprises the first gate conductor layer.
5. The device of claim 1 , wherein the charge trapping dielectric is electrically isolated from one or more other charge trapping dielectrics.
6. The device of claim 1 , wherein the charge trapping dielectric comprises a nitride layer and an dielectric layer.
7. The device of claim 6 , wherein the nitride layer comprises a silicon rich nitride.
8. The device of 1 , further comprising:
a memory dielectric disposed in the first region;
a gate dielectric disposed in the second region; and
a second gate dielectric disposed the third region,
wherein two of the memory gate dielectric, the gate dielectric, and the second gate dielectric have different thicknesses.
9. The device of 1 , wherein the dielectric comprises a nitride layer that is discontinuous from the charge trapping dielectric.
10. The device of 9 , wherein the nitride layer comprises a separate layer from the charge trapping dielectric.
11. The semiconductor device of claim 1 , wherein the first and second select gates comprise a second conductor layer.
12. The semiconductor device of claim 1 , further comprising a second memory gate disposed adjacent to the second select gate.
13. The semiconductor device of claim 12 , wherein the second select gate is disposed on a sidewall of the second memory gate.
14. The semiconductor device of claim 12 , wherein the second memory gate comprises the first gate conductor layer.
15. A semiconducting device, comprising:
a first memory cell comprising a first memory gate and a first select gate disposed on a sidewall of the first memory gate, wherein the first memory gate is disposed such that it overlaps a first charge trapping dielectric, and wherein a sidewall dielectric is disposed between the first memory gate and the first select gate;
a second memory cell comprising a second memory gate and a second select gate, wherein the second select gate is disposed on a sidewall of the second memory gate and adjacent to the first select gate, wherein the second memory gate is disposed such that it overlaps a second charge trapping dielectric, and wherein the first and second select gates are disposed between the first and second memory gates; and
a dielectric layer disposed between the first and second memory gates and beneath the first and second select gates such that the dielectric layer is shared by the first and second select gates, wherein the dielectric layer is separated from the charge trap in layer and the first memory gate by the sidewall dielectric.
16. The semiconducting device of claim 15 , wherein the first memory gate and the second memory gate comprise a first gate conductor layer.
17. The semiconducting device of claim 15 . wherein the first select gate and the second select gate comprise a second gate conductor layer.
18. The semiconducting device of claim 15 , wherein the first and second memory cells are disposed in a memory region.
19. The semiconducting device of claim 18 , further comprising a logic region that includes a logic gate.
20. The semiconducting device of claim 19 , wherein the logic region comprises a logic dielectric.
21. The semiconducting device of claim 20 , wherein the logic dielectric has a different thickness than the dielectric layer.
22. The semiconducting device of claim 15 , further comprising a first sidewall dielectric disposed between the first memory gate and the first select gate and a second sidewall dielectric disposed between the second memory gate and the second select gate.
23. The semiconducting device of claim 15 , wherein the first and second charge trapping dielectrics are non-overlapping with the dielectric layer.
24. The semiconducting device of claim 1 , wherein the dielectric layer is disposed such that it is non-overlapping with the charge trapping dielectric.