Methods of forming phase change material thin films and methods of manufacturing phase change memory devices using the same

Abstract

A method of forming a phase change material thin film comprises supplying a first precursor including Ge and a second precursor including Te into a reaction chamber concurrently to form a GeTe thin film on a substrate. A second precursor including Te and a third precursor including Sb are concurrently supplied into the reaction chamber and onto the GeTe thin film to form a SbTe thin film. The supplying of the first and second precursors and the supplying of the second and third precursors to form a GeSbTe thin film.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be described with regard to the attached drawings in which:

FIG. 1 is a flow diagram illustrating a method of forming a phase change material thin film, according to an example embodiment;

FIG. 2 is a processing timing sheet illustrating a method of forming a phase change material thin film, according to an example embodiment;

FIG. 3 is a graph illustrating component ratios of Ge, Sb, and Te in a phase change material thin film, according to an example embodiment;

FIG. 4 is a graph illustrating X-ray diffraction analysis of the crystal structure of a phase change material thin film, according to an example embodiment;

FIG. 5 is an electron microscope photograph illustrating a surface of a phase change material thin film, according to an example embodiment;

FIGS. 6A through 6K are sectional views illustrating a method of manufacturing a phase change semiconductor memory device, according to an example embodiment; and

FIGS. 7A through 7E are sectional views illustrating a method of manufacturing a phase change semiconductor memory device, according to another example embodiment.

Claims

1. A method of forming a phase change material thin film comprising: forming a first thin film on a substrate by concurrently supplying a first precursor including Ge and a second precursor including Te into a reaction chamber; andforming a second thin film on the first thin film by concurrently supplying the second precursor including Te and a third precursor including Sb into the reaction chamber.

2. The method of claim 1, wherein an inert gas and a reaction gas are supplied into the reaction chamber concurrently with the supplying of the first and second precursors, and the supplying of the second and third precursors.

3. The method of claim 1, wherein each of the first, second and third precursors are supplied along with a carrier gas including argon (Ar).

4. The method of claim 3, wherein a flow rate of the carrier gas of each precursor supplied during the forming of the first thin film is about 10 to about 400 sccm, inclusive.

5. The method of claim 3, wherein a component ratio of the first and second precursors supplied during the forming of the first thin film is about 1:1, and a total flow rate of the supplied carrier gases is about 200 sccm.

6. The method of claim 3, wherein during the forming of the first thin film the first and second precursors are supplied at a temperature of about 300 to about 500° C., inclusive, for about 0.1 to about 3.0 seconds, inclusive, under a pressure of about 0.5 to about 10 Torr, inclusive.

7. The method of claim 3, wherein a flow rate of the carrier gas of each precursor is about 10 to about 400 sccm, inclusive.

8. The method of claim 7, wherein a component ratio of the second and third precursor supplied when forming the second thin film is about 3:2, and a total flow rate of the supplied carrier gases is about 200 sccm.

9. The method of claim 7, wherein during the forming of the second thin film the second precursor and the third precursor are supplied at a temperature of about 300 to about 500° C., inclusive, for about 0.1 to about 3.0 seconds, inclusive, under a pressure of about 0.5 to about 10 Torr, inclusive.

10. The method of claim 1, further including, purging non-reacted portions of the first and second precursors from the reaction chamber after forming the first thin film.

11. The method of claim 10, wherein the purging of the non-reacted portions of the first and second precursors includes, stopping the supply of the first and second precursors to the reaction chamber, andsupplying an inert gas and a reaction gas to remove the non-reacted portions of the first and second precursors.

12. The method of claim 10, wherein the purging is performed using an inert gas and a reaction gas, the inert gas being argon (Ar) or nitrogen (N2) gas, and the reaction gas being hydrogen (H2) or ammonia (NH3) gas.

13. The method of claim 12, wherein a flow rate of a mixture gas including argon (Ar) and hydrogen (H2) as the inert gas and the reaction gas is about 10 to about 1000 sccm, inclusive.

14. The method of claim 12, wherein the flow rate of a mixture gas including argon (Ar) and hydrogen (H2) is about 400 sccm.

15. The method of claim 1, further including, purging non-reacted portions of the second and third precursors from the reaction chamber after forming the second thin film.

16. The method of claim 15, wherein the purging of the non-reacted portions of the second and third precursors includes, stopping the supply of the second and third precursors to the reaction chamber, andsupplying an inert gas and a reaction gas to remove the non-reacted portions of the second and third precursors.

17. The method of claim 1, wherein the first precursor comprises at least one selected from the group consisting of (CH3)4Ge, (C2H5)4Ge, (n-C4H9)4Ge, (i-C4H9)4Ge, (C6H5)4Ge, (CH2═CH)4Ge, (CH2CH═CH2)4Ge, (CF2═CF)4Ge, (C6H5CH2CH2CH2)4Ge, (CH3)3(C6H5)Ge, (CH3)3(C6H5CH2)Ge, (CH3)2(C2H5)2Ge, (CH3)2(C6H5)2Ge, CH3(C2H5)3Ge, (CH3)3(CH═CH2)Ge, (CH3)3(CH2CH═CH2)Ge, (C2H5)3(CH2CH═CH2)Ge, (C2H5)3(C5H5)Ge, (CH3)3GeH, (C2H5)3GeH, (C3H7)3GeH, Ge(N(CH3)2)4, Ge(N(CH3)(C2H5))4, Ge(N(C2H5)2)4, Ge(N(i-C3H7)2)4 and Ge[N(Si(CH3)3)2]4.

18. The method of claim 1, wherein the second precursor comprises at least one selected from the group consisting of Te(CH3)2, Te(C2H5)2, Te(n-C3H7)2, Te(i-C3H7)2, Te(t-C4H9)2, Te(i-C4H9)2, Te(Ch2=CH)2, Te(CH2CH═CH2)2 and Te[N(Si(CH3)3)2]2.

19. The method of claim 1, wherein the third precursor comprises at least one selected from the group consisting of Sb(CH3)3, Sb(C2H5)3, Sb(i-C3H7)3, Sb(n-C3H7)3, Sb(i-C4H9)3, Sb(t-C4H9)3, Sb(N(CH3)2)3, Sb(N(CH3)(C2H5))3, Sb(N(C2H5)2)3, Sb(N(i-C3H7)2)3 and Sb[N(Si(CH3)3)2]3.

20. The method of claim 1, wherein the forming of the first thin film and the second thin film are repeatedly performed to form the phase change material thin film.

21. The method of claim 1, wherein the first thin film is a GeTe thin film and the second thin film is a SbTe thin film.

22. A method of manufacturing a phase change memory device comprising: forming a lower electrode on a substrate;forming a phase change material thin film on the lower electrode using the method of claim 1; andforming an upper electrode on the phase change material thin film.

23. The method of claim 22, wherein an inert gas and a reaction gas are supplied into the reaction chamber concurrently with the supplying of the first and second precursors, and the supplying of the second and third precursors.

24. The method of claim 23, wherein the inert gas is argon (Ar) or nitrogen (N2), and the reaction gas is hydrogen (H2) or ammonia (NH3).

25. The method of claim 22, further including, purging non-reacted portions of the first and second precursors from the reaction chamber after forming the first thin film, andpurging non-reacted portions of the second and third precursors after forming the second thin film.

26. The method of claim 25, wherein the purging non-reacted portions of the first and second precursors includes, stopping the supply of the first and second precursors into the reaction chamber, andsupplying an inert gas and a reaction gas to remove the non-reacted portions of the first and second precursors.

27. The method of claim 25, wherein the purging non-reacted portions of the second and third precursors includes, stopping the supply of the second and third precursors into the reaction chamber, andsupplying an inert gas and a reaction gas to remove the non-reacted portions of the second and third precursors.

28. The method of claim 22, wherein the forming of the first thin film and the second thin film are repeatedly performed to form the phase change material thin film.

29. The method of claim 22, wherein each of the first, second and third precursors is supplied along with a carrier gas including argon (Ar) at a flow rate of about 10 to about 400 sccm, inclusive.

30. The method of claim 22, wherein a component ratio of the first and second precursors supplied during the forming of the first thin film is about 1:1, and a total flow rate of the supplied carrier gases is about 200 sccm.

31. The method of claim 22, wherein during the forming of the first thin film, the first and second precursor are supplied at a temperature of about 300 to about 500° C., inclusive, for about 0.1 to about 3.0 seconds, inclusive, under a pressure of about 0.5 to about 10 Torr, inclusive.

32. The method of claim 22, wherein during the forming of the second thin film, a component ratio of the supplied second and third precursors is about 3:2, and a total flow rate of the supplied carrier gases is about 200 sccm.

33. The method of claim 22, wherein during the forming of the second thin film, the second and third precursors are supplied at a temperature of about 300 to about 500° C., inclusive, for about 0.1 to about 3.0 seconds, inclusive, under a pressure of about 0.5 to about 10 Torr, inclusive.