Method and system for providing a thin film with a controlled crystal orientation using pulsed laser induced melting and nucleation-initiated crystallization

• US 20060006464A1
• Filed: 09/29/2004
• Published: 01/12/2006
• Est. Priority Date: 04/01/2002
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Choi, Jae Beom, Im, James S.
• Granted Patent: US 7,399,359 B2
• Time in Patent Office: Days
• US Class Current: 257/347
• CPC Class Codes: B23K 26/066 by using masks
• CPC Class Codes: C30B 13/24 using electromagnetic waves
• CPC Class Codes: C30B 29/02 Elements
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76867 characterized by methods of formation other than PVD, CVD or deposition from a liquids PVD H01L21/2855; CVD H01L21/28556; deposition from liquids H01L21/288

Abstract

Method and system for generating a metal thin film with a uniform crystalline orientation and a controlled crystalline microstructure are provided. For example, a metal layer is irradicated with a pulsed laser to completely melt the film throughout its entire thickness. The metal layer can then resolidify to form grains with a substantially uniform orientation. The resolidified metal layer can be irradiated with a sequential lateral solidification technique to modify the crystalline microstructure (e.g., create larger grains, single-crystal regions, grain boundary controlled microstructures, etc.) The metal layer can be irradiated by patterning a beam using a mask which includes a first region capable of attenuating the pulsed laser and a second region allowing complete irradiation of sections of the thin film being impinged by the masked laser beam. An inverse dot-patterned mask can be used, the microstructure that may have substantially the same as the geometric pattern as that of the dots of the mask.

Claims

1. A method for processing a sample having a metal thin film provided thereon to generate a polycrystalline film with a substantially uniform orientation, comprising the steps of:

(a) irradiating at least one portion of the metal thin film with a pulsed laser to completely melt the at least one portion throughout its entire thickness; and

(b) allowing the melted metal thin film to re-solidify after the at least one portion is melted, wherein the grains of the at least one resolidified portion of the metal thin film have the substantially uniform orientation.

2. The method according to claim 1, wherein the metal thin film is deposited on a substrate.

3. The method according to claim 2, wherein the metal thin film is deposited on a substrate by at least one of a sputtering procedure, an evaporation procedure and a further thin film deposition procedure.

4. The method according to claim 1, wherein the metal thin film is composed of aluminum.

5. The method according to claim 1, wherein the metal thin film is composed of an aluminum alloy, the aluminum alloy including at least one of an aluminum-copper alloy, an aluminum-silicon alloy and an aluminum-copper-silicon alloy.

6. The method according to claim 1, wherein the substantially uniform orientation is a (111) orientation.

7. The method according to claim 1, further comprising the step of:

(c) irradiating the at least one portion of the metal thin film with the laser pulse based on a sequential lateral solidification technique.

8. The method according to claim 7, wherein the laser pulse irradiating the at least one portion is patterned using a mask to modify a shape of the laser pulse.

9. The method according to claim 8, wherein the mask is comprised of a first region capable of attenuating the pulsed laser and a second region allowing a significant section of the laser beam impacting the second region to pass therethrough.

10. The method according to claim 9, wherein the mask is an inverse dot-patterned mask, and wherein the second region includes opaque array patterns which include at least one of dot-shaped areas, hexagonal-shaped areas and rectangular-shaped areas.

11. The method according to claim 10, wherein each portion of the metal thin film is completely melted throughout its entire thickness, and wherein an attenuation of the laser beam produced by the first region impinges associated section of the thin film to reach a temperature that is lower than a melting temperature of the metal thin film and lower than a temperature as further sections of the thin film corresponding with the areas irradiated by the second region.

12. The method according to claim 11, wherein dot patterns of the mask are spaced closer than a super lateral growth distance corresponding to a resolidification process temperature of the metal thin film.

13. The method according to claim 10, wherein the inverse dot-patterned mask is comprised of dots has a geometric pattern such that upon the irradiation of the metal thin film, a microstructure of the metal thin film solidifies and crystallizes in substantially the same geometric pattern as the pattern of the inverse dot-patterned mask.

14. The method according to claim 13, wherein the dots of the inverse dot-patterned mask are arranged in a pattern such that upon the irradiation of the metal thin film with the masked laser beam, a microstructure of the metal thin film is formed having one of a hexagonal pattern, a rectangular pattern and a square pattern.

15. The method according to claim 7, wherein, in step (a), a width of the at least one irradiated portion is greater than a super-lateral growth width of the metal thin film.

16. The method according to claim 1, wherein step (a) is performed using a sequential lateral solidification technique, and wherein, upon the execution of step (a), in step (b), grain-boundary location controlled grains are formed in the at least one portion of the metal thin film.

17. A system for producing at least one section of a polycrystalline metal film with a substantially uniform orientation, comprising:

a logic arrangement which is operable to;

(a) irradiate at least one portion of the at least one portion of the metal thin film to completely melt the at least one portion of the metal thin film throughout its entire thickness, and

(b) allow the at least one portion of the melted metal thin film to re-solidify after the at least one is melted, wherein the grains of the at least one portion have the substantially uniform orientation upon the re-solidification.

18. The system according to claim 17, wherein the metal thin film is deposited on a substrate.

19. The system according to claim 18, wherein the metal thin film is deposited on a substrate by at least one of a sputtering procedure, an evaporation procedure and a further thin film deposition procedure.

20. The system according to claim 17, wherein the metal thin film is composed of aluminum.

21. The system according to claim 17, wherein the metal thin film is composed of an aluminum alloy, the aluminum alloy including at least one of an aluminum-copper alloy, an aluminum-silicon alloy and an aluminum-copper-silicon alloy.

22. The method according to claim 17, wherein the substantially uniform orientation is a (111) orientation.

23. The system according to claim 17, where the logic arrangement is further operable to irradiate the at least one portion of the thin film sample with a sequential lateral solidification technique.

24. The system according to claim 23, wherein the laser pulse irradiating the at least one portion is patterned using a mask to modify a shape of the laser pulse.

25. The system according to claim 24, wherein the mask is comprised of a first region capable of attenuating the pulsed laser and a second region allowing a significant section of the laser beam impacting the second region to pass therethrough.

26. The system according to claim 25, wherein the mask is an inverse dot-patterned mask, and wherein the second region includes opaque array patterns which include at least one of dot-shaped areas, hexagonal-shaped areas and rectangular-shaped areas.

27. The system according to claim 26, wherein each portion of the metal thin film is completely melted throughout its entire thickness, and wherein an attenuation of the laser beam produced by the first region impinges associated section of the thin film to reach a temperature that is lower than a melting temperature of the metal thin film and lower than a temperature as further sections of the thin film corresponding with the areas irradiated by the second region.

28. The system according to claim 27, wherein dot patterns of the mask are spaced closer than a super lateral growth distance corresponding to a resolidification process temperature of the metal thin film.

29. The system according to claim 28, wherein the inverse dot-patterned mask is comprised of dots has a geometric pattern such that upon the irradiation of the metal thin film, a microstructure of the metal thin film solidifies and crystallizes in substantially the same geometric pattern as the pattern of the inverse dot-patterned mask.

30. The system according to claim 29, wherein the dots of the inverse dot-patterned mask are arranged in a pattern such that upon the irradiation of the metal thin film with the masked laser beam, a microstructure of the metal thin film is formed having one of a hexagonal pattern, a rectangular pattern and a square pattern.

31. The system according to claim 17, wherein the logic arrangement irradiates the at least one portion of metal using a sequential lateral solidification technique, and wherein, upon the completion of step (b), grain-boundary location controlled grains are formed in the at least one portion of the metal thin film.

32. A polycrystalline metal film, comprising:

at least one portion which is irradiated to be completely melted throughout its entire thickness, wherein the at least one portion is re-solidified after being melted, and wherein the at least one portion include grains which have a substantially uniform orientation upon the re-solidification of the at least one portion.