Process for the transfer of a thin film

• US 7,883,994 B2
• Filed: 05/11/2007
• Issued: 02/08/2011
• Est. Priority Date: 12/30/1997
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Aspar, Bernard, Bruel, Michel, Moriceau, Hubert, Maleville, Christophe
• Primary Examiner(s): Mulpuri; Savitri
• Application Number:
  US11/747,733
• Publication Number:
  US 20070232025A1
• Time in Patent Office: 1,369 Days
• Field of Search: 438/428, 438459-465, 438/113, 438/528
• US Class Current: 438/464
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate

Abstract

A process for transferring a thin film includes forming a layer of inclusions to create traps for gaseous compounds. The inclusions can be in the form of one or more implanted regions that function as confinement layers configured to trap implanted species. Further, the inclusions can be in the form of one or more layers deposited by a chemical vapor deposition, epitaxial growth, ion sputtering, or a stressed region or layer formed by any of the aforementioned processes. The inclusions can also be a region formed by heat treatment of an initial support or by heat treatment of a layer formed by any of the aforementioned processes, or by etching cavities in a layer. In a subsequent step, gaseous compounds are introduced into the layer of inclusions to form micro-cavities that form a fracture plane along which the thin film can be separated from a remainder of the substrate.

Claims

1. A process for forming a thin film from a substrate comprising the steps of:

(a) forming a layer of inclusions at a depth in the substrate corresponding to a required thickness of the thin film, wherein the layer of inclusions forms a gaseous compound trap zone and the inclusions comprise a volume of material having properties that differ from those of adjacent regions of the substrate, wherein forming an inclusion layer comprises one of sputter deposition, or epitaxial deposition, or chemical vapor deposition;

(b) implanting gaseous compounds into the gaseous compound trap zone, wherein a dose of gaseous compounds is sufficient to create micro-cavities in a fracture plane along which the thin film can be separated from the remainder of the substrate,

wherein the gaseous compounds are characterized by an implantation profile width and an average projected range (Rp) located in the trap zone, and wherein the layer of inclusions effectively reduces the width of the implantation profile and increases the concentration of gaseous compounds around the Rp, as compared to the absence of the layer of inclusions; and

(c) separating the thin film from the substrate along the fracture plane and thereafter recovering the thin film.

2. The process for forming a thin film according to claim 1, wherein forming the layer of inclusions comprises inclusions having crystalline parameters that differ relative to the adjacent regions of the substrate.

3. The process for forming a thin film according to claim 2, wherein forming the layer of inclusions comprises forming inclusions having a crystalline grain size that differs from a crystalline grain size of adjacent regions of the substrate.

4. The process for forming a thin film according to claim 2, wherein forming the layer of inclusions comprises sputter deposition of a layer having columnary crystalline grains.

5. The process for forming a thin film according to claim 2, wherein forming the layer of inclusions comprises sputter deposition of a layer having a granular crystalline structure.

6. The process for forming a thin film according to claim 1, wherein forming the layer of inclusions comprises forming inclusions having a crystalline orientation along a plane parallel to the surface of the thin film material that differs from a crystalline orientation of the adjacent regions of the substrate.

7. The process for forming a thin film according to claim 6, further comprising forming a seed layer on the substrate and forming the layer of inclusions on the seed layer, wherein the crystalline orientation of the seed layer substantially matches the crystalline orientation of the substrate.

8. The process for forming a thin film according to claim 1, wherein forming a layer of inclusions comprises forming inclusions having a coefficient of thermal expansion that substantially differs from a coefficient of thermal expansion of adjacent regions of the substrate.

9. The process for forming a thin film according to claim 1, wherein separating and recovering the thin film comprises placing a support in intimate contact with the substrate such that the thin film bonds to the support.