METHOD OF TRANSFERRING A THIN FILM ONTO A SUPPORT

• US 20090120568A1
• Filed: 08/11/2006
• Published: 05/14/2009
• Est. Priority Date: 08/16/2005
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Dechamp, Jerome, Deguet, Chrystel, Clavelier, Laurent
• Granted Patent: US 8,142,593 B2
• Time in Patent Office: Days
• US Class Current: 156/250
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 156/109 Embedding of laminae within face of additional laminae

Abstract

A method of transferring a thin film onto a first support, includes supplying a structure comprising a film of which at least one part originates from a solid substrate of a first material and which is solidly connected to a second support having a thermal expansion coefficient that is different from that of the first material and close to that of the first support, forming an embrittled area inside the film that defines the thin film to be transferred, affixing the film that is solidly connected to the second support to the first support, and breaking the film at the embrittled area.

Claims

1. A method for transferring a thin layer comprising a first material onto a first support comprising a second material, the method comprising:

providing a structure comprising a layer at least a portion of which is derived from a bulk substrate of the first material, wherein the layer is attached to a second support comprising a third material having a coefficient of thermal expansion that is different from a coefficient of thermal expansion of the first material and that is similar to a coefficient of thermal expansion of the second material;

forming a buried weakened zone in the layer at a given depth, the buried weakened zone delimiting in the structure the thin layer to be transferred;

bonding the layer to the first support; and

fracturing the layer in the weakened zone, wherein the fracturing is carried out with a process comprising at least one heat treatment step.

2. The method according to claim 1, wherein a thickness of the layer is dependent on the mechanical behavior as a function of temperature of the structure obtained after bonding the layer to the first support.

3. The method according to claim 1, wherein fracturing the layer further comprises applying mechanical loads.

4. The method according to claim 1, wherein forming a buried weakened zone comprises implanting at least one gaseous species.

5. The method according to claim 1, wherein the coefficient of thermal expansion of the first material differs from each of the coefficients of thermal expansion of the second and third materials by at least 10%.

6. The method according to claim 1, wherein the coefficient of thermal expansion of the second material is different from the coefficient of thermal expansion of the third material by less than 10%.

7. The method according to claim 6, wherein the second material is identical to the third material.

8. The method according to claim 1, wherein the thickness of the layer is less than 15% of the thickness of the second support.

9. The method according to claim 1, wherein the second material comprises silicon.

10. The method according to claim 1, wherein the first material comprises germanium.

11. The method according to claim 1, wherein the thickness of the layer is between 1 μ

m and 50 μ

m.

12. The method according to claim 1, further comprising bonding a bulk plate of the first material to the second support.

13. The method according to claim 12, wherein bonding the bulk plate is carried out at a temperature between 100°

C. and 200°

C.

14. The method according to claim 12, further comprising thinning the bulk plate to obtain the layer.

15. The method according to claim 1, further comprising epitaxially depositing an epitaxial layer comprising the first material, wherein the epitaxial layer is deposited on a portion of the layer that remains attached to the second support after fracturing.

16. The method according to claim 15, further comprising:

forming a buried weakened zone in the epitaxial layer;

bonding the epitaxial layer onto a third support; and

fracturing the epitaxial layer in the weakened zone.

17. The method according to claim 1, wherein the layer is obtained entirely from the bulk substrate.

18. The method according to claim 1, wherein the layer comprises an epitaxial layer of the first material.

19. The method according to claim 18, wherein the layer comprises an epitaxial layer of a fourth material of a thickness such that a crystalline structure of the layer is imparted by the first material.

20. The method according to claim 18, further comprising eliminating the epitaxial layer of the first material after fracture using the epitaxial layer of the fourth material as a stop layer.