Method for producing a low defect homogeneous oxynitride
View Patent ↗A process technology effectuates production of low defect homogeneous oxynitride, which can be applied in tunneling dielectrics with high dielectric constants and low barrier heights for flash memory devices, and as gate oxide for ultra-thin logic devices. The process technology involves varying the oxygen content in a the homogeneous oxynitride film comprising a part of the flash memory device, which effectively increases the dielectric constant of the oxynitride film and lowers its barrier height. In one such process, a controlled co-flow of N 2 O is introduced into a CVD deposition process. This process effectuates production of a oxynitride film with uniform distributions of nitrogen and oxygen throughout.
1. A method for producing a low defect homogeneous oxynitride on a substrate, comprising:
depositing an oxynitride layer above a substrate wherein said low defect homogeneous oxynitride comprises a tunneling dielectric having high capacitance and low barrier heights, wherein the dielectric constant corresponding to said oxynitride layer has a value within the range or 3.9 to 7.8, wherein the barrier height corresponding to said oxynitride layer has a value in the range of 3.2 to 2.1 electron Volts, wherein said depositing comprises one or more of an in-furnace process and a chemical vapor deposition process wherein said chemical vapor deposition process is selected from the group consisting essentially of rapid thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, and low pressure chemical vapor deposition; and
adding nitrous oxide with a mixture of gases selected from the group consisting essentially of silane, silethane, and ammonia during said depositing of said oxynitride, wherein said oxynitride on said substrate has uniform distributions of nitrogen and oxygen wherein said dielectric constant and said barrier height facilitates Fowler-Nordheim tunneling and Channel Hot Electron tunneling of electrons in said oxynitride layer, wherein said Channel Hot Electron tunneling allows source-side channel hot hole injection in a device comprised of said low defect homogeneous oxynitride on a substrate.
2. The method as recited in claim 1 , further comprising:
cleaning a surface of said substrate;
oxidizing said surface of said substrate;
improving the quality of an interface;
adjusting the concentration of nitrogen in said interface; and
performing a backend flow process.
3. The method as recited in claim 2 wherein said cleaning and said oxidizing are performed prior to said deposition.
4. The method as recited in claim 2 wherein said improving, said adjusting, and said performing are performed after said deposition.
5. The method as recited in claim 2 wherein said cleaning comprises application of a cleanser selected from the group consisting essentially of hydrogen fluoride and solvents.
6. The method as recited in claim 2 wherein said oxidizing comprises application of an oxide of nitrogen in situ.
7. The method as recited in claim 2 wherein said improving and said adjusting comprise oxidation.
8. The method as recited in claim 7 wherein said oxidation is performed by application of an oxidant selected from the group consisting essentially of an oxide of nitrogen and oxygen.
9. The method as recited in claim 1 wherein said low defect homogeneous oxynitride comprises a gate oxide for ultra-thin gate logic devices.
10. The method as recited in claim 1 wherein said homogeneous oxynitride is applied in a device selected from the group consisting essentially of a flash memory device and an ultra-thin gate logic device.
11. A method for producing a low defect homogeneous oxynitride on a substrate, comprising:
cleaning a surface of said substrate;
oxidizing a surface of said substrate;
depositing an oxynitride layer above said substrate wherein said oxynitride layer comprises a tunneling dielectric having high capacitance and low barrier heights, wherein the dielectric constant corresponding to said oxynitride layer has a value within the range or 3.9 to 7.8, wherein the barrier height corresponding to said oxynitride layer has a value in the range of 3.2 to 2.1 electron Volts, and wherein said depositing comprises one or more of an in-furnace process and a chemical vapor deposition process wherein said chemical vapor deposition process is selected from the group consisting essentially of rapid thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, and low pressure chemical vapor deposition;
improving the quality of an interface;
adjusting the concentration of nitrogen in said interface, wherein said oxynitride on said substrate has uniform distributions of nitrogen and oxygen wherein said dielectric constant and said barrier height facilitates Fowler-Nordheim tunneling and Channel Hot Electron tunneling of electrons in said oxynitride layer, wherein said Channel Hot Electron tunneling allows a source-side channel hot hole injection in a device comprised of said low defect homogeneous oxynitride on a substrate; and
performing a backend flow process.
12. The method as recited in claim 11 wherein said cleaning comprises application of a cleanser selected from the group consisting essentially of hydrogen fluoride and solvents.
13. The method as recited in claim 11 wherein said oxidizing comprises application of an oxide of nitrogen in situ.
14. The method as recited in claim 11 wherein said improving and said adjusting comprise oxidation.
15. The method as recited in claim 14 wherein said oxidation is performed by application of an oxidant selected from the group consisting essentially of an oxide of nitrogen and oxygen.
16. The method as recited in claim 11 wherein said low defect homogeneous oxynitride comprises a gate oxide for ultra-thin gate logic devices.
17. The method as recited in claim 11 wherein said homogeneous oxynitride is applied in a device selected from the group consisting essentially of a flash memory device and an ultra-thin gate logic device.