Chemical vapor deposition furnace with a cleaning gas system to provide a cleaning gas

Patent metadata

Field	Value
Publication number	US-12077854-B2
Application number	US-202217810773-A
Country	US
Kind code	B2
Filing date	Jul 5, 2022
Priority date	Jul 6, 2021
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A chemical vapor deposition furnace for depositing silicon nitride films is disclosed. The furnace includes a process chamber elongated in a substantially vertical direction and a wafer boat for supporting a plurality of wafers in the process chamber. A process gas injector inside the process chamber is provided with vertically spaced gas injection holes to provide gas introduced at a feed end in an interior of the process gas injector to the process chamber. A valve system connected to the feed end of the process gas injector is being constructed and arranged to connect a source of a silicon precursor and a nitrogen precursor to the feed end for depositing silicon nitride layers. The valve system may connect the feed end of the process gas injector to a cleaning gas system to provide a cleaning gas to remove silicon nitride from the process gas injector and/or the process chamber.

First claim

The invention claimed is:

1. A chemical vapor deposition furnace for depositing silicon nitride films on a plurality of wafers comprising:
a process chamber elongated in a substantially vertical direction;
a wafer boat for supporting the plurality of wafers in the process chamber;
a process gas injector inside the process chamber extending in the substantially vertical direction along the wafer boat and provided with a plurality of vertically spaced gas injection holes to provide gas introduced at a feed end in an interior of the process gas injector to the process chamber;
a liner accommodating the process gas injector and extending in the substantially vertical direction to radially surround the wafer boat, the liner including a cover portion covering an end of the wafer boat opposite to the feed end of the process gas injector in the substantially vertical direction;
a valve system operably connected to the feed end of the process gas injector and being constructed and arranged to connect a source of a silicon precursor and a source of a nitrogen precursor to the feed end of the process gas injector for depositing silicon nitride layers, wherein the valve system is further constructed and arranged to connect the feed end of the process gas injector to a cleaning gas system to provide a cleaning gas to the interior to remove silicon nitride from at least one of the process gas injector and the process chamber;
a purge system disposed proximate to a lower end of the process chamber entirely below the liner, the purge system configured to provide an inert gas directly into the lower end of the process chamber below the liner; and
a controller operably connected to the valve system, the cleaning gas system and the purge system to control the purge system to provide a purge gas to dilute the cleaning gas in the process chamber during supply of the cleaning gas and to control the purge system to provide inert gas directly to the process chamber decoupled from inert gas being provided, via vertically spaced injection holes, to the process chamber.

2. The chemical vapor deposition furnace of claim 1 , wherein the plurality of gas injection holes of the process gas injector extend over substantially a height of the wafer boat.

3. The chemical vapor deposition furnace of claim 1 , wherein the cleaning gas system is connected to a cleaning gas source.

4. The chemical vapor deposition furnace of claim 1 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas mixed with an inert gas.

5. The chemical vapor deposition furnace of claim 4 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas mixed with argon, helium or nitrogen as the inert gas.

6. The chemical vapor deposition furnace of claim 1 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas comprising at least one halogen selected from the group comprising fluorine, chlorine, bromine and iodine.

7. The chemical vapor deposition furnace of claim 1 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas comprising nitrogen trifluoride NF 3 .

8. The chemical vapor deposition furnace of claim 1 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas comprising fluorine F 2 .

9. The chemical vapor deposition furnace of claim 4 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas in a 1 to 20% mixture with helium as the inert gas.

10. The chemical vapor deposition furnace of claim 1 , wherein the cleaning gas system is constructed and arranged to provide the cleaning gas at a flow rate between 10 to 300 cubic centimeters per minute (SCCM).

11. The chemical vapor deposition furnace of claim 1 , wherein the deposition furnace is constructed and arranged to provide the cleaning gas with the cleaning gas system at a partial pressure between 0.01 and 0.5 Torr in the interior of the process gas injector.

12. The chemical vapor deposition furnace of claim 1 , wherein the deposition furnace is constructed and arranged to provide the cleaning gas with the cleaning gas system at a partial pressure between 0.001 and 0.1 Torr in the process chamber.

13. The chemical vapor deposition furnace of claim 1 , wherein the purge system is disposed below the wafer boat and configured to provide the inert gas directly into the lower end of the process chamber below the wafer boat.

14. The chemical vapor deposition furnace of claim 1 , further comprising:
a heater to heat the process chamber,
wherein the controller is operably connected to the valve system, the cleaning gas system, purge system, and the heater to control the heater to heat the process chamber during cleaning.

15. The chemical vapor deposition furnace of claim 14 , wherein the heater is constructed and arranged to create a temperature difference over the process chamber in the substantially vertical direction and the controller controls the heater to provide a higher temperature in the top of the process chamber compared to the bottom of the process chamber during cleaning.

16. The chemical vapor deposition furnace of claim 1 , further comprising:
a pump to remove gas from the process chamber,
wherein the controller is operably connected to the valve system, the cleaning gas system, the purge system, and the pump to control the pump to remove gas from the process chamber during cleaning.

17. The chemical vapor deposition furnace of claim 1 , wherein the covering portion is dome shaped.

18. The chemical vapor deposition furnace of claim 1 , further comprising:
a gas exhaust opening disposed at the lower end of the process chamber below the feed end of the process gas injector, the gas exhaust opening configured to allow gas to flow outward from the process chamber.

19. The chemical vapor deposition furnace of claim 18 , further comprising:
a purge line configured to provide a purge gas to the process chamber, wherein the purge line is closer to the wafer boat and further from the lower end of the process chamber than the gas exhaust opening.

Assignees

• Asm Ip Holding Bv

Inventors

• Pierreux Dieter
• Oosterlaken Theodorus G M
• Terhorst Herbert
• Jdira Lucian
• Jongbloed Bert

Classifications

• C23C16/45561

  Gas plumbing upstream of the reaction chamber · CPC title

• C23C16/4583

  the substrate being supported substantially horizontally · CPC title

• C23C16/52

  Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} · CPC title

• C23C16/455

  characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber · CPC title

• C23C16/345 Primary

  Silicon nitride · CPC title