Method of forming carbon polymer film using plasma CVD

• US 20070224833A1
• Filed: 03/23/2006
• Published: 09/27/2007
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV), Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: ASM Japan K.K. (ASM International NV), Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Matsuki, Nobuo, Morisada, Yoshinori, Yamaguchi, Masashi, Na, Kyu, Baek, Eun, Goundar, Kamal
• Granted Patent: US 7,410,915 B2
• Time in Patent Office: Days
• US Class Current: 438/758
• CPC Class Codes: B05D 1/62 Plasma-deposition of organic layers plasma deposition in general C23C14/00, C23C16/00
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/3127 Layers comprising fluoro (hydro)carbon compounds, e.g. polytetrafluoroethylene
• CPC Class Codes: H01L 21/32139 using masks

Abstract

A method of forming a hydrocarbon-containing polymer film on a semiconductor substrate by a capacitively-coupled plasma CVD apparatus. The method includes the steps of: vaporizing a hydrocarbon-containing liquid monomer (C_αH_βX_γ, wherein α and β are natural numbers of 5 or more; γ is an integer including zero; X is O, N or F) having a boiling point of about 20° C. to about 350° C. which is not substituted by a vinyl group or an acetylene group; introducing the vaporized gas and CO₂ gas or H₂ gas into a CVD reaction chamber inside which a substrate is placed; and forming a hydrocarbon-containing polymer film on the substrate by plasma polymerization of the gas, thereby reducing extinction coefficient (k) at 193 nm and increasing mechanical hardness.

Claims

1. A method of forming a hydrocarbon-containing polymer film on a semiconductor substrate by a capacitively-coupled plasma CVD apparatus, which comprises:

vaporizing a hydrocarbon-containing liquid monomer (C_α

H_β

X_γ

, wherein α and

β

are natural numbers of 5 or more;

γ

is an integer including zero;

X is O, N or F) having a boiling point of about 20°

C. to about 350°

C. which is not substituted by a vinyl group or an acetylene group;

introducing said vaporized gas and CO₂ gas or H₂ gas into a CVD reaction chamber inside which a substrate is placed; and

forming a hydrocarbon-containing polymer film on said substrate by plasma polymerization of said gas and controlling an extinction coefficient at 193 nm and a mechanical hardness of the forming hydrocarbon-containing polymer film at 0.38 or less and 0.5 GPa or higher, respectively, as a function of a flow rate of the CO₂ gas or H₂ gas.

2. The method according to claim 1, wherein the flow rate of the CO₂ gas or H₂ gas is greater than a flow rate of the vaporized gas.

3. The method according to claim 1, wherein the CO₂ gas is used at a flow rate of 350 sccm or more.

4. The method according to claim 2, wherein the CO₂ gas is used at a flow rate of 800 sccm or more.

5. The method according to claim 1, wherein the H₂ gas is used at a flow rate of 200 sccm or more.

6. The method according to claim 5, wherein the H₂ gas is used at a flow rate of 300 sccm or more.

7. The method according to claim 1, wherein the extinction coefficient and the mechanical hardness of the forming hydrocarbon-containing polymer film are controlled at 0.35 or less and 0.8 GPa or higher, respectively, as a function of the flow of the CO₂ gas or H₂ gas.

8. The method according to claim 1, wherein the extinction coefficient and the mechanical hardness of the forming hydrocarbon-containing polymer film are controlled further as a function of a temperature of the substrate.

9. The method according to claim 8, wherein the temperature is controlled at 400°

C. or higher.

10. The method according to claim 1, wherein said liquid monomer is a cyclic hydrocarbon.

11. The method according to claim 10, wherein said cyclic hydrocarbon is a substituted or non-substituted benzene.

12. The method according to claim 11, wherein said substituted or non-substituted benzene is C₆H_6-nR_n (wherein n is 0, 1, 2, or 3);

R is independently —

CH3 or —

C2H5.

13. The method according to claim 12, wherein said substituted benzene is any one of 1,3,5-trimethylbenzene, o-xylene, m-xylene or p-xylene.

14. The method according to claim 1, wherein said liquid monomer is a linear hydrocarbon.

15. The method according to claim 1, wherein said liquid monomer is a hydrocarbon wherein γ

is equal to zero.

16. The method according to claim 1, wherein only said liquid monomer is used as a reaction gas.

17. The method according to claim 1, wherein said liquid monomer is introduced into a heater disposed upstream of said reaction chamber and vaporized.

18. The method according to claim 17, wherein said liquid monomer is flow-controlled upstream of said heater by a valve, and its introduction into said heater is blocked, except when a film is being formed, by a shutoff valve disposed between said flow control valve and said heater and kept approximately at 80°

C. or lower or at a temperature which is at least approximately 50°

C. lower than that of vaporization by heat.

19. The method according to claim 17, wherein said liquid monomer is flow-controlled by a valve, which is disposed upstream of said heater and kept at approximately 80°

C. or lower or at a temperature which is at least approximately 50°

C. lower than that of vaporization by heat, and its introduction into said heater is blocked except when a film is being formed.

20. The method according to claim 1, further comprising introducing an inert gas into the reaction chamber prior to the plasma polymerization.

21. The method according to claim 1, wherein as an additive gas, an organic gas CnHm (wherein n is an integer of 4 or less including zero;

m is any natural number) is further introduced into the reaction chamber.

22. The method according to claim 1, wherein as an additive gas, a dry gas containing N, O and F is further introduced into the reaction chamber.

23. A method of forming a hydrocarbon-containing polymer film on a semiconductor substrate by a capacitively-coupled plasma CVD apparatus, which comprises the steps of:

placing a semiconductor device substrate in a CVD reaction chamber;

vaporizing a hydrocarbon-containing liquid monomer (C_α

H_β

X_γ

, wherein α and

β

are natural numbers of 5 or more;

γ

is an integer including zero;

X is O, N or F) having a boiling point of about 20°

C. to about 350°

C.;

introducing said vaporized gas and CO₂ gas or H₂ gas into the CVD reaction chamber inside which the substrate is placed; and

forming a hard mask comprising a hydrocarbon-containing polymer film on said substrate by plasma polymerization of said gas and controlling an extinction coefficient at 193 nm and a mechanical hardness of the forming hydrocarbon-containing polymer film at 0.38 or less and 0.5 GPa or higher, respectively, as a function of a flow rate of the CO₂ gas or H₂ gas.

24. The method according to claim 23, wherein the flow rate of the CO₂ gas or H₂ gas is greater than a flow rate of the vaporized gas.

25. The method according to claim 23, wherein the CO₂ gas is used at a flow rate of 350 sccm or more.

26. The method according to claim 25, wherein the CO₂ gas is used at a flow rate of 800 sccm or more.

27. The method according to claim 23, wherein the H₂ gas is used at a flow rate of 200 sccm or more.

28. The method according to claim 27, wherein the H₂ gas is used at a flow rate of 300 sccm or more.

29. The method according to claim 23, wherein the extinction coefficient and the mechanical hardness of the forming hydrocarbon-containing polymer film are controlled at 0.35 or less and 0.8 GPa or higher, respectively, as a function of the flow of the CO₂ gas or H₂ gas.

30. The method according to claim 25, wherein the extinction coefficient and the mechanical hardness of the forming hydrocarbon-containing polymer film are controlled further as a function of a temperature of the substrate.

31. The method according to claim 30, wherein the temperature is controlled at 400°

C. or higher.

32. The method according to claim 23, wherein said liquid monomer is a cyclic hydrocarbon.

33. The method according to claim 32, wherein said cyclic hydrocarbon is a substituted or non-substituted benzene.

34. The method according to claim 23, wherein said liquid monomer is a linear hydrocarbon.

35. The method according to claim 23, wherein said liquid monomer is a hydrocarbon wherein γ

is equal to zero.

36. The method according to claim 23, wherein only said liquid monomer is used as a reaction gas.

37. The method according to claim 23, wherein said liquid monomer is introduced into a heater disposed upstream of the reaction chamber and vaporized.

38. The method according to claim 37, wherein said liquid monomer is flow-controlled upstream of said heater by a valve, and its introduction into said heater is blocked, except when a film is being formed, by a shutoff valve disposed between said flow control valve and said heater and kept approximately at 80°

C. or lower or at a temperature which is at least approximately 50°

C. lower than that of vaporization by heat.

39. The method according to claim 37, wherein said liquid monomer is flow-controlled by a valve, which is disposed upstream of said heater and kept at approximately at 80°

C. or lower or at a temperature which is at least approximately 50°

C. lower than that of vaporization by heat, and its introduction into said heater is blocked except when a film is being formed.

40. The method according to claim 23, further comprising introducing an inert gas into the reaction chamber prior to the plasma polymerization.