Method of depositing dielectric films

• US 6,764,958 B1
• Filed: 07/28/2000
• Issued: 07/20/2004
• Est. Priority Date: 07/28/2000
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lee, Jia, Sugiarto, Dian, Nemani, Srinivas D, Campana-Schmitt, Francimar, Xia, Li-Qun, Xu, Ping, Yieh, Ellie
• Primary Examiner(s): Coleman, W. David
• Assistant Examiner(s): NGUYEN, KHIEM D
• Application Number:
  US09/627,667
• Time in Patent Office: 1,453 Days
• Field of Search: 438/763, 438/931, 438/952, 438/689, 438/695, 438/638, 438/738, 438/633, 438/634, 438/626, 438/FOR.131, 438/355, 438/700, 438/702, 438/717, 438/740, 438/784
• US Class Current: 438/758
• CPC Class Codes: C23C 16/325 Silicon carbide
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02131 the material being halogen doped silicon oxides, e.g. FSG
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/0332 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/3081 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/314 Inorganic layers H01L21/3105, H01L21/32 take precedence
• CPC Class Codes: H01L 21/3148 Silicon Carbide layers
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: Y10S 438/931 : Silicon carbide semiconductor

Abstract

A method of forming a silicon carbide layer for use in integrated circuit fabrication processes is provided. The silicon carbide layer is formed by reacting a gas mixture comprising a silicon source, a carbon source, and a dopant in the presence of an electric field. The as-deposited silicon carbide layer has a compressibility that varies as a function of the amount of dopant present in the gas mixture during later formation.

Claims

1. A method of thin film deposition, comprising:

positioning a substrate in a deposition chamber;

providing a gas mixture to the deposition chamber, wherein the gas mixture comprises a organosilane compound and a dopant selected from the group of ammonia (NH₃), methane (CH₄), silane (SiH₄), ethylene (C₂H₄), acetylene (C₂H₂), and combinations thereof;

reacting the gas mixture in the presence of a first electric field to form a doped silicon carbide layer on the substrate, wherein the doped silicon carbide layer has a compressibility that varies as a function of the amount of dopant in the gas mixture; and

then

exposing the doped silicon carbide layer deposited on the substrate to a plasma generated by providing one or more inert gas to a process chamber and applying a second electric field to the one or more inert gases.

2. The method of claim 1, wherein the organosilane compound has the general formula Si_xC_yH_z, wherein x has a range of 1 to 2, y has a range of 1 to 6, and z has a range of 4 to 18.

3. The method of claim 2, wherein the organosilane compound is selected from the group of methyl silane (SiCH₆), dimethylsilane (SIC₂H₈), trimethylsilane (SiC₃H₁₀), tetramethylsilane (SiC₄H₁₂), diethylsilane (SiC₄H₁₂), and combinations thereof.

4. The method of claim 1, wherein the gas mixture further comprises an inert gas.

5. The method of claim 4 wherein the inert gas is selected from the group of helium (He), argon (Ar), nitrogen (N₂), and combinations thereof.

6. The method of claim 1, wherein the ratio of the organosilane compound to the dopant in the gas mixture has a range of about 1:

1 to about 1;

100.

7. The method of claim 1 wherein the substrate is heated to a temperature between about 150°

C. to about 450°

C.

8. The method of claim 1 wherein the deposition chamber is maintained at a pressure between about 1 torr to about 15 torr.

9. The method of claim 1, wherein the organosilane compound is provided to the deposition chamber at a flow rate in a range of about 10 sccm to about 4000 sccm.

10. The method of claim 1 wherein the dopant is provided to the deposition chamber at a flow rate in a range of about 50 sccm to about 10,000 sccm.

11. The method of claim 1 wherein the electric field is generated from one or more radio frequency (RF) powers.

12. The method of claim 11 wherein each of the one or more RF powers is in a range of about 100 watts to about 1000 watts.

13. The method of claim 1 wherein the doped silicon carbide layer has a dielectric constant less than about 5.5.

14. The method of claim 1 wherein the doped silicon carbide layer is an anti-reflectve coating (ARC) at wavelengths less than about 250 nm.

15. The method of claim 1 wherein the doped silicon carbide layer has a leakage current less than about 10⁻

8 A/cm² at 2 MV/cm².

16. The method of claim 1, wherein the one or more inert gases are selected from the group of helium (He), argon (Ar) and nitrogen (N₂), and combinations thereof.

17. The method of claim 1, wherein the process chamber is maintained at a pressure in a range of about 5 torr to about 10 torr.

18. The method of claim 1, wherein the one or more inert gases are provided to the deposition chamber at a flow rate in a range of about 1000 sccm to about 7000 sccm.

19. The method of claim 1, wherein the electric field is a radio frequency (RF) power.

20. The method of claim 19 wherein the RF power is in a range of about 200 watts to about 1000 watts.

21. A method of forming a device, comprising:

forming a doped silicon carbide layer on a substrate in a deposition chamber, wherein the doped silicon carbide layer is formed by reacting a gas mixture comprising an organosilane compound and a dopant selected from the group of ammonia (NH₃), methane (CH₄), silane (SiH₄), ethylene (C₂H₄), acetylene (C₂H₂), and combinations thereof, and wherein the doped silicon carbide layer has a compressibility that varies as a function of the amount of dopant in the gas mixture;

exposing the doped silicon carbide layer deposited on the substrate to a plasma generated by providing one or more inert gas to a process chamber and applying a second electric field to the one or more inert gases;

forming an intermediate layer on the doped silicon carbide layer;

forming a layer of energy sensitive resist material on the intermediate layer;

introducing an image of the pattern into the layer of energy sensitive resist material by exposing the energy sensitive resist material to patterned radiation;

developing the image of the pattern introduced into the layer of energy sensitive resist material;

transferring the image of the pattern developed in the layer of energy sensitive resist material through the intermediate layer using the energy sensitive resist material as a mask; and

transferring the pattern through the doped silicon carbide layer using the intermediate layer as a mask.

22. The method of claim 21, wherein the intermediate layer is an oxide or silicon carbide cap layer.

23. The method of claim 22 wherein the oxide is selected from the group of silicon dioxide, fluorosilicate glass (FSG), and silicon oxynitride.

24. The method of claim 21, wherein the compressibility of the deposited doped silicon carbide layer increases as the dopant concentration in the doped silicon carbide layer increases.

25. The method of claim 21, wherein the organosilane compound having the general formula Si_xC_yH_z, wherein x has a range of 1 to 2, y has a range of 1 to 6, and z has a range of 4 to 18.

26. The method of claim 25, wherein the organosilane compound is selected from the group of methyl silane (SiCH₆), dimethylsilane (SiC₂H₈), trimethylsilane (SiC₃H₁₀), tetramethylsilane (SiC₄H₁₂), diethylsilane (SiC₄H₁₂), and combinations thereof.

27. The method of claim 21, wherein the gas mixture further comprises an inert gas selected from the group of helium (He), argon (Ar), nitrogen (N₂), and combinations thereof.

28. The method of claim 21, wherein the ratio of the organosilane compound to the dopant in the gas mixture has a range of about 1:

1 to about 1;

100.

29. The method of claim 21, wherein the doped silicon carbide layer has a dielectric constant less than about 5.5, the doped silicon carbide layer is an anti-reflective coating (ARC) at wavelengths less than about 250 nm, and the doped silicon carbide layer has a leakage current less than about 10⁻

8 A/cm² at 2 MV/Cm².

30. A method of forming a device, comprising:

forming a doped silicon carbide layer on a substrate in a deposition chamber, wherein the doped silicon carbide layer is formed by reacting a gas mixture comprising an organosilane compound and a dopant selected from the group of ammonia (NH₃), methane (CH₄), silane (SiH₄), ethylene (C₂H₄), acetylene (C₂H₂), and combinations thereof, and wherein the doped silicon carbide layer has a compressibility that varies as a function of the amount of dopant in the gas mixture;

forming an intermediate layer on the doped silicon carbide layer, wherein the intermediate layer is a silicon carbide cap layer;

forming a layer of energy sensitive resist material on the intermediate layer,

introducing an image of the pattern into the layer of energy sensitive resist material by exposing the energy sensitive resist material to patterned radiation;

developing the image of the pattern introduced into the layer of energy sensitive resist material;

transferring the image of the pattern developed in the layer of energy sensitive resist material through the intermediate layer using the energy sensitive resist material as a mask; and

transferring the pattern through the doped silicon carbide layer using the intermediate layer as a mask.

31. The method of claim 30, wherein the compressibility of the deposited doped silicon carbide layer increases as the dopant concentration in the doped silicon carbide layer increases.

32. The method of claim 30, wherein the organosilane compound having the general formula Si_xC_yH_z, wherein x has a range of 1 to 2, y has a range of 1 to 6, and z has a range of 4 to 18.

33. The method of claim 32, wherein the organosilane compound is selected from the group of methyl silane (SiCH₆), dimethylsilane (SiC₂H₈), trimethylsilane (SiC₃H₁₀), tetramethylsilane (SiC₄H₁₂), diethylsilane (SiC₄H₁₂), and combinations thereof.

34. The method of claim 30, wherein the gas mixture further comprises an inert gas selected from the group of helium (He), argon (Ar), nitrogen (N₂), and combinations thereof.

35. The method of claim 30, wherein the ratio of the organosilane compound to the dopant in the gas mixture has a range of about 1:

1 to about 1;

100.

36. The method of claim 30, wherein the doped silicon carbide layer has a dielectric constant less than about 5.5, the doped silicon carbide layer is an anti-reflective coating (ARC) at wavelengths less than about 250 nm, and the doped silicon carbide layer has a leakage current less than about 10⁻

8 A/cm² at 2 MV/cm².

37. A method of forming a device, comprising:

forming a doped silicon carbide layer on a substrate in a deposition chamber, wherein the doped silicon carbide layer is formed by reacting a gas mixture comprising an organosilane compound and a dopant selected from the group of methane (CH₄), silane (SiH₄), ethylene (C₂H₄), acetylene (C₂H₂), and combinations thereof, and wherein the doped silicon carbide layer has a compressibility that varies as a function of the amount of dopant in the gas mixture;

forming an intermediate layer on the doped silicon carbide layer;

forming a layer of energy sensitive resist material on the intermediate layer;

introducing an image of the pattern into the layer of energy sensitive resist material by exposing the energy sensitive resist material to patterned radiation;

developing the image of the pattern introduced into the layer of energy sensitive resist material;

transferring the image of the pattern developed in the layer of energy sensitive resist material through the intermediate layer using the energy sensitive resist material as a mask; and

transferring the pattern through the doped silicon carbide layer using the intermediate layer as a mask.

38. The method of claim 37, wherein the intermediate layer is an oxide or silicon carbide cap layer.

39. The method of claim 38 wherein the oxide is selected from the group of silicon dioxide, fluorosilicate glass (FSG), and silicon oxynitride.

40. The method of claim 37, wherein the compressibility of the deposited doped silicon carbide layer increases as the dopant concentration in the doped silicon carbide layer increases.

41. The method of claim 37, wherein the organosilane compound having the general formula Si_xC_yH_z, wherein x has a range of 1 to 2, y has a range of 1 to 6, and z has a range of 4 to 18.

42. The method of claim 41, wherein the organosilane compound Is selected from the group of methyl silane (SiCH₆), dimethylsilane (SiC₂H₈), trimethylsilane (SiC₃H₁₀), tetramethylsilane (SiC₄H₁₂), diethylsilane (SiC₄H₁₂), and combinations thereof.

43. The method of claim 37, wherein the gas mixture further comprises an inert gas selected from the group of helium (He), argon (Ar), nitrogen (N₂), and combinations thereof.

44. The method of claim 37, wherein the ratio of the organosilane compound to the dopant in the gas mixture has a range of about 1:

1 to about 1;

100.

45. The method of claim 37, wherein the doped silicon carbide layer has a dielectric constant less than about 5.5, the doped silicon carbide layer is an anti-reflective coating (ARC) at wavelengths less than about 250 nm, and the doped silicon carbide layer has a leakage current less than about 10⁻

8 A/cm² at 2 MV/cm².