Method and system for producing crystalline thin films with a uniform crystalline orientation

• US 20070007242A1
• Filed: 03/10/2006
• Published: 01/11/2007
• Est. Priority Date: 09/16/2003
• Status: Abandoned Application

• 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: Im, James
• Application Number:
  US11/373,771
• Publication Number:
  US 20070007242A1
• Time in Patent Office: Days
• US Class Current: 216/62
• CPC Class Codes: C03C 23/0025 by a laser beam
• CPC Class Codes: C30B 28/00 Production of homogeneous polycrystalline material with defined structure
• CPC Class Codes: C30B 28/08 by zone-melting
• CPC Class Codes: C30B 35/00 Apparatus not otherwise provided for, specially adapted for the growth, production or after-treatment of single crystals or of a homogeneous polycrystalline material with defined structure
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02678 Beam shaping, e.g. using a mask
• CPC Class Codes: H01L 21/02683 Continuous wave laser beam
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/02689 using particle beams
• CPC Class Codes: H01L 21/02691 Scanning of a beam
• CPC Class Codes: H01L 27/1285 using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors
• CPC Class Codes: H01L 27/1296 adapted to increase the uniformity of device parameters

Abstract

System and method generating a polycrystalline thin film with a particular crystalline orientation for use as thin film transistors, microelectronic devices and the like. In one exemplary embodiment, a polycrystalline silicon thin film that has a substantially uniform crystalline orientation is produced so that its crystals are provided in at least one direction. The crystalline orientation may be any low index orientation and may be achieved with sequential lateral solidification. The polycrystalline thin film may then be crystallized in a direction that is perpendicular to the first direction by, e.g., a sequential lateral solidification procedure so that the crystalline orientation is approximately the same as the first direction, and is substantially uniform in all directions.

Claims

1. A method of generating a particular crystalline orientation in at least one section of a thin film sample, comprising the steps of:

(a) arranging the thin film sample in a first position;

(b) irradiating at least one portion of the at least one section of the thin film sample to form at least one polycrystalline section of the thin film sample, the at least one polycrystalline section having an approximately uniform crystalline orientation in a first direction;

(c) arranging the thin film sample to be in a second position with respect to the at least one beam pulse, the second position being approximately perpendicular relative to the first position; and

(d) irradiating the at least one polycrystalline section of the thin film sample arranged in the second position so as to provide an approximately uniform crystalline orientation in a second direction, the second direction being approximately perpendicular relative to the first direction, wherein the at least one polycrystalline section of the thin film sample has an approximately uniform crystalline orientation in both the first direction and the second direction.

2. The method according to claim 1, wherein, after step (b) further comprising the step of irradiating the thin film sample at positions along the first direction until the thin film sample is irradiated across the entire sample.

3. The method according to claim 1, wherein, after step (b) further comprising the step of irradiating the thin film sample at positions along the first direction alternating from side to side with respect to the first irradiation position until the thin film sample is irradiated across the entire sample.

4. The method according to claim 2 or 3, wherein the pulses impinge the thin film sample at a distance greater than the lateral growth distance of the previous irradiation.

5. The method according to claim 1, wherein, after step (d), the crystalline orientation of the thin film sample is uniform in all directions.

6. The method of claim 1, wherein the thin film sample is a silicon thin film.

7. The method of claim 1, wherein the thin film sample is a metal thin film sample.

8. The method of claim 1, wherein the thin film sample is an aluminum thin film sample.

9. The method of claim 1, wherein steps (b) and (d) are performed using a sequential lateral solidification process.

10. The method of claim 1, wherein the uniform crystalline orientation is an arbitrary low index orientation.

11. The method of claim 1, wherein the uniform crystalline orientation is the {100} plane.

12. The method of claim 1, wherein the uniform crystalline orientation is the {110} plane.

13. The method of claim 1, wherein the uniform crystalline orientation is the {111} plane.

14. A system for generating a particular crystalline orientation in at least one section of a thin film sample, comprising:

a logic arrangement which is operable to;

(a) irradiate at least one portion of the at least one section of the thin film sample when the thin film sample is arranged in a first position so as to form at least one polycrystalline section of the thin film sample, the at least one polycrystalline section having a substantially uniform crystalline orientation in a first direction,

(b) arrange the thin film sample to be in a second position with respect to the at least one beam pulse, the second position being approximately perpendicular relative to the first position, and

(c) irradiate the at least one polycrystalline section of the thin film sample, when the thin film sample is arranged in the second position, so as to provide an approximately uniform crystalline orientation to be in a second direction, the second direction being perpendicular to first direction, wherein the at least one polycrystalline section of the thin film sample has an approximately uniform crystalline orientation in both the first direction and the second direction.

15. The system of claim 14, wherein, after step (a) further comprising the step of irradiating the thin film sample at positions along the first direction until the thin film sample is irradiated across the entire sample.

16. The system of claim 14, wherein, after step (a) further comprising the step of irradiating the thin film sample at positions along the first direction alternating from side to side with respect to the first irradiation position until the thin film sample is irradiated across the entire sample.

17. The system of claim 15 or 16, wherein the pulses impinge the thin film sample at a distance less than the lateral growth distance of the previous irradiation.

18. The system of claim 14, wherein, after step (c), the crystalline orientation of the thin film sample is uniform in all directions.

19. The system of claim 14, wherein the thin film sample is a silicon thin film.

20. The system of claim 14, wherein steps (a) and (c) are performed using a sequential lateral solidification process.