Methods of fabricating silicon-on-insulator substrates having a laser-formed single crystalline film

Abstract

In some methods of fabricating a silicon-on-insulator substrate, a semiconductor substrate is provided that includes a single crystalline structure within at least a defined region thereof. A first insulating film is formed on the defined region of the semiconductor substrate with an opening that exposes a portion of the defined region of the semiconductor substrate having the single crystalline structure. A first non-single crystalline film is formed on the exposed portion of the semiconductor substrate and that at least substantially fills the opening in the first insulating film. A laser beam is generated that heats the first non-single crystalline film to change the first non-single crystalline film into a first single crystalline film having substantially the same single crystalline structure as the defined region of the semiconductor substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate certain embodiments of the invention. In the drawings:

FIG. 1 is a cross-sectional view that illustrates a semiconductor device including a SOI substrate and illustrates associated methods of fabricating the same according to some embodiments of the present invention;

FIGS. 2 a-f are cross-sectional views illustrating methods of fabricating SOI substrates and semiconductor devices that include SOI substrates in accordance with some embodiments of the present invention;

FIGS. 3 a-f are cross-sectional views illustrating methods of fabricating SOI substrates and semiconductor devices that include SOI substrates in accordance with some other embodiments of the present invention; and

FIGS. 4 a-f are cross-sectional views illustrating methods of fabricating SOI substrates and semiconductor devices that include SOI substrates in accordance with yet some other embodiments of the present invention.

Claims

1. A method of fabricating a silicon-on-insulator (SOI) substrate, the method comprising: providing a semiconductor substrate having a single crystalline structure within at least a defined region thereof;forming a first insulating film pattern on the defined region of the semiconductor substrate with an opening that exposes a portion of the defined region of the semiconductor substrate having the single crystalline structure;forming a first non-single crystalline film on the exposed portion of the semiconductor substrate and that at least substantially fills the opening in the first insulating film pattern; andgenerating a laser beam that heats the first non-single crystalline film to change the first non-single crystalline film into a first single crystalline film having substantially the same single crystalline structure as the defined region of the semiconductor substrate.

2. The method of fabricating the SOI substrate of claim 1, further comprising preheating the semiconductor substrate before generating the laser beam to reduce a temperature gradient between the laser heated first non-single crystalline film and the semiconductor substrate.

3. The method of fabricating the SOI substrate of claim 2, wherein preheating the semiconductor substrate before generating the laser beam comprises preheating the semiconductor substrate to above about 100° C. and maintaining the semiconductor substrate at one or more temperatures above about 100° C. while generating the laser beam to reduce a temperature gradient between the laser heated first non-single crystalline film and the semiconductor substrate.

4. The method of fabricating the SOI substrate of claim 1, wherein generating a laser beam comprises heating the first non-single crystalline film for a time period of between about 1 nanosecond to about 1,000 nanoseconds so that the first non-single crystalline film is in a melted state for a sufficiently brief time to not substantially flow across an upper surface of the first insulating film pattern.

5. The method of fabricating the SOI substrate of claim 4, wherein generating a laser beam comprises heating the first non-single crystalline film for a time period of between about 5 nanoseconds to about 200 nanoseconds.

6. The method of fabricating the SOI substrate of claim 1, wherein generating a laser beam is carried out using a Nd Yttrium-Aluminum-Garnet (YAG) laser apparatus, a carbon laser apparatus, and/or an excimer laser apparatus.

7. The method of fabricating the SOI substrate of claim 1, further comprising: forming a first insulating film on the semiconductor substrate;forming a second insulating film on the first insulating film;removing a portion of the second insulating film to form a second insulating film pattern with an opening exposing a portion of the first insulating film; andbefore forming the first non-single crystalline film, removing a portion of the first insulating film through the opening in the second insulating film to form the first insulating film pattern with the opening that exposes the portion of the defined region of the semiconductor substrate having the single crystalline structure.

8. The method of fabricating the SOI substrate of claim 7, wherein: forming a first non-single crystalline film comprises forming the first non-single crystalline film on the exposed portion of the semiconductor substrate and that fills the opening in the first insulating film pattern and at least partially fills the opening in the second insulating film pattern; andgenerating a laser beam comprises heating the first non-single crystalline film to change the first non-single crystalline film into the first single crystalline film having substantially the same single crystalline structure as the defined region of the semiconductor substrate in at least a major region of the first non-single crystalline film adjacent to the opening in the first insulating film pattern.

9. The method of fabricating the SOI substrate of claim 8, wherein generating the laser beam comprises melting the first non-single crystalline film in at least the major region adjacent to the opening in the first insulating film pattern so that the first single crystalline structure of the semiconductor substrate forms a seed film which changes lattice parameters of the melted first non-single crystalline film to have substantially the same single crystalline structure as the defined region of the semiconductor substrate.

10. The method of fabricating the SOI substrate of claim 8, wherein: forming a first non-single crystalline film comprises depositing amorphous silicon and/or polycrystalline silicon on the exposed portion of the semiconductor substrate and filling the opening in the first insulating film pattern and at least partially filling the opening in the second insulating film pattern; andgenerating a laser beam comprises heating the first non-single crystalline film in at least the major region adjacent to the opening in the first insulating film pattern to a temperature above a melting point of silicon.

11. The method of fabricating the SOI substrate of claim 8, wherein the first insulating film pattern is formed from a material having an etch selectivity that is different from an etch selectivity of the second insulating film pattern.

12. The method of fabricating the SOI substrate of claim 11, wherein: forming the first insulating film comprises depositing one of a silicon nitride film and a silicon oxide film; andforming the second insulating film comprising depositing a different one of the silicon nitride film and the silicon oxide film from the lower insulating film.

13. The method of fabricating the SOI substrate of claim 11, wherein removing a portion of the second insulating film comprises etching the second insulating film using the first insulating film as an etch stop.

14. The method of fabricating the SOI substrate of claim 13, wherein removing a portion of the first insulating film comprises etching the first insulating film using the second insulating film as an etching mask.

15. The method of fabricating the SOI substrate of claim 1, wherein the first insulating film pattern is formed having a thickness that is sufficient to function as a buried insulating film between the first single crystalline film and the semiconductor substrate.

16. The method of fabricating the SOI substrate of claim 15, wherein the second insulating film pattern is formed having a thickness that is sufficient to function as an element isolation film between a semiconductor device formed on the first single crystalline film and another adjacent semiconductor device formed on the semiconductor substrate on an opposite side of the second insulating film pattern.

17. The method of fabricating the SOI substrate of claim 1, wherein forming the first non-single crystalline film comprises depositing amorphous silicon and/or polycrystalline silicon on the exposed portion of the semiconductor substrate to fill the opening in the first insulating film pattern and at least partially fill the opening in the second insulating film pattern.

18. The method of fabricating the SOI substrate of claim 17, wherein the first non-single crystalline film is formed by chemical vapor deposition using a silicon source gas including silane (SiH4) and/or hexadichlorosilane (Si2H6).

19. The method of fabricating the SOI substrate of claim 1, further comprising doping impurities into the first non-single crystalline film before generating the laser beam.

20. The method of fabricating the SOI substrate of claim 19, wherein doping impurities into the first non-single crystalline film before generating the laser beam comprises supplying a phosphorous source gas to dope phosphorous into the first non-single crystalline film and/or supplying a boron source gas to dope boron into the first non-single crystalline film.

21. The method of fabricating the SOI substrate of claim 19, wherein doping impurities into the first non-single crystalline film before generating the laser beam comprises implanting impurity ions into the first non-single crystalline film.

22. The method of fabricating the SOI substrate of claim 1, further comprising planarizing an upper surface of the first single crystalline film to form a first single crystalline film pattern having an upper surface that is substantially aligned with an upper surface of the second insulating film pattern.

23. The method of fabricating the SOI substrate of claim 1, further comprising: forming a second insulating film on the first insulating film with an opening that exposes at least a portion of the first single crystalline film;forming a second non-single crystalline film on the exposed first single crystalline film and that at least partially fills the opening in the second insulating film; andgenerating a second laser beam that heats the second non-single crystalline film to change the second non-single crystalline film into a second single crystalline film having substantially the same single crystalline structure as the first single crystalline film in at least a major region of the second non-single crystalline film adjacent to the first single crystalline film in the opening in the first insulating film.

24. The method of fabricating the SOI substrate of claim 23, further comprising planarizing an upper surface of the first single crystalline film to make it substantially aligned with an upper surface of the first insulating film before forming the second non-single crystalline film on the first single crystalline film.

25. The method of fabricating the SOI substrate of claim 24, wherein the upper surface of the first single crystalline film is planarized using chemical mechanical polishing (CMP).

26. The method of fabricating the SOI substrate of claim 24, wherein the upper surface of the first single crystalline film is planarized before generating the laser beam that heats the first non-single crystalline film to change the first non-single crystalline film into the first single crystalline film.

27. The method of fabricating the SOI substrate of claim 24, further comprising planarizing an upper surface of the second single crystalline film to make it substantially aligned with an upper surface of the second insulating film.

28. The method of fabricating the SOI substrate of claim 1, further comprising: forming the first insulating film pattern with a plurality of spaced apart openings exposing portions of the defined region of the semiconductor substrate;forming the first single crystalline film in the plurality of openings in the first insulating film pattern, the first single crystalline film forming a first single crystalline film pattern;forming a second insulating film pattern on the first insulating film pattern with a plurality of spaced apart openings each of which exposes a plurality of the first single crystalline film pattern in the plurality of openings in the first insulating film pattern;forming a second non-single crystalline film on the exposed plurality of the first single crystalline film pattern and at least partially fills the plurality of openings in the second insulating film; andgenerating a second laser beam to heat the second non-single crystalline film and change the second non-single crystalline film in the plurality of openings in the second insulating film into a second single crystalline film having substantially the same single crystalline structure as the first single crystalline film pattern.

29. The method of fabricating the SOI substrate of claim 28, further comprising: forming a first mask covering the second single crystalline film pattern in first ones of the plurality of openings in the second insulating film while leaving exposed the second single crystalline film in second ones of the plurality of openings in the second insulating film;doping first conductivity type impurities into the second single crystalline film in the second ones of the plurality of openings in the second insulating film while using the mask to block dopants from entering the second single crystalline film in the first ones of the plurality of openings in the second insulating film;removing the first mask;forming a second mask covering the second single crystalline film pattern in the second ones of the plurality of openings in the second insulating film while leaving exposed the second single crystalline film in the first ones of the plurality of openings in the second insulating film;doping second conductivity type impurities, which are opposite to the first conductive type impurities, into the second single crystalline film in the first ones of the plurality of openings in the second insulating film while using the mask to block dopants from entering the second single crystalline film in the second ones of the plurality of openings in the second insulating film.

30. The method of fabricating the SOI substrate of claim 29, further comprising: removing the second mask;forming a third insulating film pattern on the second insulating film pattern with a plurality of spaced apart openings exposing portions of the second single crystalline film pattern;forming a third non-single crystalline film on the exposed portions of the second single crystalline film pattern and filling the plurality of openings in the second insulating film;generating a third laser beam to heat the third non-single crystalline film and change the third non-single crystalline film in the plurality of openings in the third insulating film into a third single crystalline film having substantially the same single crystalline structure as the second single crystalline film pattern;forming a fourth insulating film pattern on the third insulating film pattern with a plurality of spaced apart openings each of which exposes a plurality of the third single crystalline film in the plurality of openings in the third insulating film pattern;forming a fourth non-single crystalline film on the exposed plurality of the third single crystalline film and at least partially filling the plurality of openings in the third insulating film; andgenerating a fourth laser beam to heat the fourth non-single crystalline film and change the force non-single crystalline film in the plurality of openings in the fourth insulating film into a force single crystalline film having substantially the same single crystalline structure as the third single crystalline film pattern.

31. The method of fabricating the SOI substrate of claim 1, wherein: the first insulating film is formed with a plurality of spaced apart openings that expose portions of the defined region of the semiconductor substrate having the single crystalline structure;the first non-single crystalline film is formed on the first insulating film and exposed portions of the semiconductor substrate through the plurality of openings in the first insulating film; andthe laser beam heats the first non-single crystalline film to change the first non-single crystalline film into the first single crystalline film in at least a major region of the first non-single crystalline film adjacent to the plurality of openings in the first insulating film.

32. The method of fabricating the SOI substrate of claim 31, further comprising: planarizing an upper surface of the first single crystalline film to make it substantially aligned with an upper surface of the first insulating film;forming a second insulating film on the first insulating film with an opening that exposes the first single crystalline film in the plurality of openings in the first insulating film;forming a second non-single crystalline film on the exposed first single crystalline film and filling the opening in the second insulating film;generating a second laser beam that heats and changes the second non-single crystalline film into a second single crystalline film having substantially the same single crystalline structure as the first single crystalline film;planarizing an upper surface of the second single crystalline film to make it substantially aligned with an upper surface of the second insulating film;forming a third insulating film on the second insulating film with a plurality of spaced apart openings that expose portions of the second single crystalline film;forming a third non-single crystalline film on the exposed second single crystalline film in the plurality of openings in the third insulating film;generating a third laser beam that heats and changes the third non-single crystalline film into a third single crystalline film having substantially the same single crystalline structure as the second single crystalline film;planarizing an upper surface of the third single crystalline film to make it substantially aligned with an upper surface of the third insulating film;forming a fourth insulating film on the third insulating film with an opening that exposes the third single crystalline film in the plurality of openings in the third insulating film;forming a fourth non-single crystalline film on the exposed third single crystalline film and that at least partially fills the opening in the fourth insulating film; andgenerating a fourth laser beam that heats and changes the fourth non-single crystalline film into a fourth single crystalline film having substantially the same single crystalline structure as the third single crystalline film.

33. The method of fabricating the SOI substrate of claim 1, further comprising: forming a second insulating film on the lower insulating film;removing a portion of the second insulating film to form an opening exposing a portion of the first insulating film;before forming the first non-single crystalline film, removing portions of the first insulating film, through the opening in the second insulating film, to form a plurality of spaced apart openings that expose portions of the defined region of the semiconductor substrate having the single crystalline structure;forming the first non-single crystalline film on the exposed portion of the semiconductor substrate to fill the plurality of openings in the first insulating film and at least partially fill the opening in the second insulating film;heating the first non-single crystalline film using the laser beam to change the first non-single crystalline film into the first single crystalline film;planarizing an upper surface of the first single crystalline film to make it substantially aligned with an upper surface of the second insulating film;forming a third insulating film on the second insulating film;forming a fourth insulating film on the third insulating film;removing a portion of the fourth insulating film to form an opening exposing a portion of the third insulating film;removing portions of the third insulating film, through the opening in the fourth insulating film, to form a plurality of spaced apart openings that expose portions of the first single crystalline film;forming a second non-single crystalline film on the exposed portions of the first single crystalline film and to fill the plurality of openings in the third insulating film and at least partially fill the opening in the fourth insulating film; andgenerating a laser beam that heats the second non-single crystalline film to change the second non-single crystalline film into a second single crystalline film having substantially the same single crystalline structure as the first single crystalline film.