Dielectric stack
View Patent ↗A method of forming a device is disclosed. The method includes providing a substrate and forming a device layer on the substrate having a formed thickness T FD . A capping layer is formed on the substrate having a formed thickness T FC . Forming the capping layer consumes a desired amount of the device layer to cause the thickness of the device layer to be about the target thickness T TD . The thickness of the capping layer is adjusted from T FC to about a target thickness T TC .
1. A device comprising:
a substrate;
a first dielectric device layer on the substrate comprising a target thickness T TFD ; and
a second dielectric device layer over the first dielectric device layer having a target thickness T TSD , wherein a lower portion of the second dielectric device layer comprises a consumed upper portion of the first dielectric device layer.
2. The device of claim 1 wherein:
the first dielectric device layer comprises a nitride material and the second dielectric device layer comprises a thermally grown oxide material.
3. The device of claim 2 wherein the nitride material comprises silicon nitride and the thermally grown oxide material comprises in-situ steam generated (ISSG) silicon oxide.
4. The device of claim 1 wherein a top surface of the second dielectric device layer comprises an etch surface.
5. The device of claim 1 comprises a third device layer below the first dielectric device layer.
6. The device of claim 5 wherein the first, second and third device layers form a dielectric stack.
7. The device of claim 1 wherein the thicknesses T TFD and T TSD are tightly controlled.
8. The device of claim 1 wherein the consumed upper portion of the first dielectric device layer is based on growth rate of the second dielectric device layer represented by a formula y=1.6301x−1.0003, wherein y is an amount of grown second dielectric device layer and x is an amount of consumption of the first dielectric device layer.
9. The device of claim 8 wherein:
the first dielectric device layer comprises a nitride material and the second dielectric device layer comprises a thermally grown oxide material.
10. A device comprising:
a substrate; and
a gate having a gate electrode and a gate dielectric stack disposed over the substrate, wherein the gate dielectric stack comprises
a first device layer on the substrate comprising a target thickness T TFD , and
a second device layer over the first device layer having a target thickness T TSD , wherein a lower portion of the second device layer comprises a consumed upper portion of the first device layer.
11. The device of claim 10 wherein:
the first device layer comprises a nitride material and the second device layer comprises a thermally grown oxide material.
12. The device of claim 11 wherein the nitride material comprises silicon nitride and the thermally grown oxide material comprises in-situ steam generated (ISSG) silicon oxide.
13. The device of claim 10 wherein a top surface of the second device layer comprises an etch surface.
14. The device of claim 10 wherein the dielectric stack further comprises a third device layer below the first device layer.
15. The device of claim 14 wherein the first, second and third device layers serve as a gate dielectric of a non-volatile memory.
16. The device of claim 15 wherein the first device layer serves as a charge storage layer, the second device layer serves a capping layer and the third device layer serves as a tunneling layer.
17. The device of claim 10 wherein the consumed upper portion of the first device layer is based on growth rate of the second device layer represented by a formula y=1.6301x−1.0003, wherein y is an amount of grown second device layer and x is an amount of consumption of the first device layer.
18. A device comprising:
a substrate;
a base dielectric layer on the substrate;
first dielectric device layer on the base dielectric layer comprising a target thickness T TFD ; and
a second dielectric capping layer over the first dielectric device layer having a target thickness T TSD , wherein a lower portion of the second dielectric capping layer comprises a consumed upper portion of the first dielectric device layer.
19. The device of claim 18 wherein:
the first device layer comprises a nitride material and the second and third dielectric layers comprise a thermally grown oxide material.
20. The device of claim 19 wherein the nitride material comprises silicon nitride and the thermally grown oxide material comprises in-situ steam generated (ISSG) silicon oxide.