High efficiency method for performing a chemical vapordeposition utilizing a nonvolatile precursor

• US 7,182,979 B2
• Filed: 08/05/2002
• Issued: 02/27/2007
• Est. Priority Date: 05/14/1993
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sandhu, Gurtej S., Westmoreland, Donald L.
• Primary Examiner(s): CHEN, BRET P
• Application Number:
  US10/213,030
• Publication Number:
  US 20020192376A1
• Time in Patent Office: 1,667 Days
• Field of Search: 427/248.1, 427/250, 427/252, 427/255.28, 427/255.31, 427/421
• US Class Current: 427/248.1
• CPC Class Codes: C23C 16/4485 by evaporation without using carrier gas in contact with the source material C23C16/4486 takes precedence

Abstract

A method directed to the use of a nonvolatile precursor, either a solid or liquid precursor, suitable for CVD, including liquid source CVD (LSCVD). Using the method of the invention the nonvolatile precursor is dissolved in a solvent. Choice of solvent is typically an inorganic compound that has a moderate to high vapor pressure at room temperature, which can be liquified by combination of pressure and cooling. The solution is then transported at an elevated pressure and/or a reduced temperature to the CVD chamber. The solution evaporates at a higher temperature and a lower pressure upon entry to the CVD chamber, and the nonvolatile precursor, in its gaseous state, along with a gas reactant, produces a product which is deposited on a semiconductor wafer. In LSCVD the liquid enters the chamber, contacts the wafer, evaporates, produces a product which is deposited as a thin film.

Claims

1. A method for performing a chemical vapor deposition, comprising:

providing a solution comprising a nonvolatile precursor suitable for chemical vapor deposition dissolved in a solvent, wherein the solvent is an inorganic liquid;

transporting the solution as a liquid stream to a chemical vapor deposition chamber;

subjecting the solution to a temperature and pressure higher than atmospheric pressure sufficient to maintain the solution in a liquid state during transporting;

nebulizing the liquid stream in the chemical vapor deposition chamber;

applying the nebulized liquid stream to a semiconductor wafer surface, wherein the wafer surface is at a temperature less than that of the solution during transporting; and

subjecting the nebulized liquid stream to a temperature and a vacuum pressure in the chemical vapor deposition chamber by raising the wafer to a temperature sufficient to rapidly evaporate the solvent after the solution contacts the semiconductor wafer.

2. The method according to claim 1, wherein the nonvolatile precursor and the solvent do not react with each other in liquid form.

3. The method according to claim 1, wherein the solvent is liquid ammonia, liquid NO₂, liquid SO₂, liquid TiCl₄, liquid xenonfourides, liquid phosphine, liquid arsine, diethylzinc, BCl₃, BF₃, SF₆, H₂S, SiF₄, CBrF₃, CCl₂F₂, CCl₃F, CClF₃, CCl₄, or SiH₂Cl₂.

4. The method according to claim 1, wherein the precursor is a solid.

5. The method of claim 1, wherein the precursor is bis(cyclopentadienyl) titanium dichloride, ZrCl₄, or tungsten carbonyl.

6. The method of claim 1, wherein the precursor is a nonvolatile liquid.

7. The method of claim 1, wherein the precursor is indenyltris(dimethylamido)zirconium, cyclopentadienylitris(diethylamido)titanium, or bis(cyclopentadienyl)bis(dimethylamido)titanium.

8. The method of claim 1, wherein subjecting the solution to a temperature and a pressure in the chemical vapor deposition chamber sufficient to evaporate the solution includes reacting the precursor with a reactant to form a film on the surface of the wafer.

9. A method for performing a chemical vapor deposition, comprising:

dissolving a precursor suitable for chemical vapor deposition in a volatile inorganic solvent to form a solution;

transporting the solution as a continuous liquid stream to a chemical vapor deposition chamber;

subjecting the solution to a temperature and pressure higher than about twice atmospheric pressure sufficient to maintain the solution in a liquid state during transporting;

nebulizing the liquid stream as it enters the chemical vapor deposition chamber;

applying the solution to a semiconductor wafer, wherein the semiconductor wafer is at a temperature less than that of the solution; and

subjecting the solution to a high enough temperature and a low enough vacuum pressure in the chemical vapor deposition chamber by raising the semiconductor wafer to a high enough temperature to evaporate the solvent after the solution contacts the semiconductor wafer.

10. The method according to claim 9, wherein dissolving a precursor includes selecting a precursor and a solvent that do not react with each other in liquid form.

11. The method according to claim 9, wherein the volatile inorganic solvent is liquid ammonia.

12. The method according to claim 9, wherein the precursor is selected from the group consisting of bis(cyclopentadienyl) titanium dichloride, ZrCl₄, tungsten carbonyl, indenyltris(dimethylamido) zirconium, cyclopentadienyltris(dietheylamido) titanium, and bis(cyclopentadienyl) bis(dimethylamido) titanium.

13. A method for performing a chemical vapor deposition, comprising:

dissolving a precursor suitable for chemical vapor deposition in an inorganic solvent to form a solution, the solvent being selected from the group consisting of liquid ammonia, liquid NO₂, liquid SO₂, liquid TiCl₄, liquid TaCl₅, liquid WF₆, liquid SiCl₄, borazine, dimethyl hydrazine, liquid xenonflourides, liquid phosphine, liquid arsine, diethylzinc, BCl₃, BF₃, SF₆, H₂S, SiF₄, CBrF₃, CCl₂F₂, CCl₃F, CClF₃, CCl₄, and SiH₂Cl₂;

transporting the solution as a continuous liquid stream to a chemical vapor deposition chamber;

subjecting the solution to a temperature and pressure higher than about twice atmospheric pressure sufficient to maintain the solution in a liquid state during transporting;

nebulizing the liquid stream in the chemical vapor deposition chamber;

applying the solution to a semiconductor wafer surface, wherein the semiconductor wafer is at a temperature less than that of the solution; and

subjecting the solution to a temperature and a vacuum pressure in the chemical vapor deposition chamber by raising the semiconductor wafer to a temperature sufficient to rapidly evaporate the solution after the solvent contacts the semiconductor wafer.

14. The method according to claim 13, further comprising selecting a precursor and a solvent that do not react with each other in liquid form.

15. The method according to claim 13, wherein the precursor is bis(cyclopentadienyl) titanium diazide and the solvent is liquid ammonia.

16. The method according to claim 13, wherein the pressure sufficient to maintain the solution in a liquid state is 120 psi or greater and the temperature sufficient to maintain the solution in a liquid state is 20°

C. or less.

17. A method for performing a chemical vapor deposition, comprising:

dissolving zirconium tetrachloride in silicon tetrachloride to form a solution;

transporting the solution as a continuous liquid stream to a chemical vapor deposition chamber;

subjecting the solution to a temperature and pressure higher than atmospheric pressure sufficient to maintain the solution in a liquid state during transporting;

nebulizing the liquid stream in the chemical vapor deposition chamber;

applying the nebulized liquid stream to a semiconductor wafer, wherein the semiconductor wafer is at a temperature less than that of the solution; and

subjecting the nebulized liquid stream on the semiconductor wafer to a high enough temperature and a low enough vacuum pressure in the chemical vapor deposition chamber by raising the semiconductor wafer to a high enough temperature to rapidly evaporate the solvent after the solution contacts the semiconductor wafer.

18. The method according to claim 17, wherein the pressure sufficient to maintain the solution in a liquid state is 60 psi or greater and the temperature sufficient to maintain the solution in a liquid state is between 60°

C. and 10°

C.

19. A method for performing a chemical vapor deposition, comprising:

dissolving a precursor suitable for chemical vapor deposition in an inorganic solvent to form a solution;

transporting the solution as a continuous liquid stream to a chemical vapor deposition chamber;

subjecting the solution to a temperature and pressure about twice atmospheric pressure sufficient to maintain the solution in a liquid state during transporting;

nebulizing the liquid stream in the chemical vapor deposition chamber; and

rapidly evaporating the nebulized liquid stream in the chemical vapor deposition chamber by raising a temperature of a semiconductor wafer after the solution contacts the semiconductor wafer.

20. The method according to claim 19, further comprising selecting a precursor and a solvent that do not react with each other in liquid form.

21. The method according to claim 19, wherein the inorganic solvent is liquid ammonia.

22. The method according to claim 19, wherein the precursor is selected from the group consisting of bis(cyclopentadienyl) titanium dichloride, ZrCl₄, tungsten carbonyl, indenyltris(dimethylamido) zirconium, cyclopentadienyltris(dietheylamido) titanium, and bis(cyclopentadienyl) bis(dimethylamido) titanium.

23. The method of claim 19, wherein the inorganic solvent is a volatile inorganic solvent.

24. A deposition method, comprising:

maintaining a solution of a precursor and liquid solvent in a liquid form, wherein the liquid solvent is an inorganic liquid;

transporting the solution as a liquid stream to a deposition chamber;

nebulizing the liquid stream in the deposition chamber; and

rapidly evaporating the nebulized liquid stream in the deposition chamber by raising a temperature of a semiconductor wafer after the solution contacts the wafer.

25. The method of claim 24, wherein evaporating the solution includes raising the temperature of the solution.

26. The method of claim 24, wherein evaporating the solution includes lowering the pressure acting on the solution.

27. The method of claim 24, wherein maintaining the solution includes subjecting the solution to a temperature and pressure that keeps the solution in the liquid form.

28. The method of claim 24, wherein transporting the solution includes subjecting the solution to a temperature and pressure that keeps the solution in the liquid form.

29. The method of claim 24, wherein the precursor is selected from the group consisting of bis(cyclopentadienyl) titanium dichloride, ZrCl₄, tungsten carbonyl, indenyltris(dimethylamido) zirconium, cyclopentadienyltris(dietheylamido) titanium, and bis(cyclopentadienyl) bis(dimethylamido) titanium.

30. The method of claim 24, wherein maintaining the solution includes selecting the precursor and the solvent so that they do not react with each other in the liquid form.

31. The method of claim 24, wherein evaporating the solution in the deposition chamber includes chemical vapor depositing the precursor on a wafer.

32. The method of claim 31, wherein chemical vapor depositing the precursor includes reacting the precursor with a reactant on the wafer.

33. The method of claim 24, wherein maintaining the solution in a liquid form includes subjecting the solution to a pressure of 60 psi or greater and a temperature between 60°

C. and 10°

C.

34. The method of claim 24, wherein evaporating the solution in the deposition chamber includes subjecting the solution to a pressure of 10 torr and a temperature of 600°

C.

35. The method of claim 24, wherein nebulizing the liquid stream in the chemical vapor deposition chamber includes delivering the nebulized stream to a surface of a substrate, and wherein evaporating the nebulized liquid stream includes subjecting the solution to a temperature and a pressure in the chemical vapor deposition chamber sufficient to form a film on the surface of the substrate.