Embrittled substrate and method for making same

• US 7,498,245 B2
• Filed: 05/29/2001
• Issued: 03/03/2009
• Est. Priority Date: 05/30/2000
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Lagahe, Chrystelle, Aspar, Bernard, Ghyselen, Bruno, Rayssac, Olivier
• Primary Examiner(s): MENZ, LAURA MARY
• Application Number:
  US10/276,306
• Publication Number:
  US 20030077885A1
• Time in Patent Office: 2,835 Days
• Field of Search: 438/514, 438/459, 438/460
• US Class Current: 438/514
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate

Abstract

This invention relates to a substrate (1) weakened by the presence of a micro-cavities zone, the micro-cavities zone (4′) delimiting a thin layer (5) with one face (2) of the substrate (1), some or all of the gaseous species having been eliminated from the micro-cavities (4′).

The invention also relates to a process for the production of such a substrate.

Claims

1. A process for making a removable substrate comprising:

introducing a gaseous species into a zone of the substrate to form micro-cavities in the zone, the zone thereby being weakened and delimiting a thin layer with one face of the substrate;

heat-treating, after said introducing, the zone of the substrate during a given time to thereby evacuate the gaseous species from the micro-cavities without causing a separation in the substrate because a temperature of the heat treating and the given time being such that a separation of the thin layer from a remaining part of the substrate does not occur during the heat-treating; and

performing, after said heat-treating, a technological step requiring a high temperature.

2. Process according to claim 1, wherein the introducing of the at least one gaseous species includes ionic implantation.

3. Process according to claim 1, wherein the heat-treating allows at least some of the gaseous species added to leave the micro-cavities by diffusion.

4. Processing according to claim 3, wherein the heat-treating includes application of stresses to the weakened zone.

5. Process according to claim 3, wherein the substrate is a semiconductor substrate, and the heat-treating is applied during manufacture of at least one component in the thin layer.

6. Process according to 1, further comprising over-weakening of the weakened zone.

7. Processing according to claim 6, further comprising depositing a stiffening layer on the thin layer, before the over-weakening.

8. Process according to claim 6, wherein the over-weakening includes a heat treatment applied to the weakened zone before the evacuating.

9. Process according to claim 6, wherein the over-weakening includes applying stresses in the weakened zone.

10. Process according to claim 6, wherein the over-weakening includes introducing of at least one further gaseous species in the weakened zone.

11. Process according to claim 10, wherein the at least one further gaseous species is introduced into the weakened zone using a method chosen from among ionic implantation, thermally activated diffusion, and plasma diffusion.

12. Process according to claim 6, wherein the over-weakening induces localized over-weakening of the weakened zone.

13. Process according to claim 6, wherein the substrate is a semiconductor substrate, and the over-weakening of the weakened one is done during manufacture of at least part of at least one component in the thin layer.

14. Process according to claim 1, wherein the substrate is a semiconductor substrate, and further comprising manufacturing at least one part of at least one component in the thin layer, after the gaseous species has been evacuated from the weakened zone.

15. Process according to claim 14, wherein the manufacturing comprises an epitaxy or heteroepitaxy.

16. Process according to claim 14, wherein after the at least one part of the at least one component has been made, the process further comprises introducing a further gaseous species.

17. Process according to claim 1, further comprising solidarization of a face of the thin layer with a stiffener.

18. Process according to claim 1, wherein the introducing of the at least one gaseous species into a substrate zone is done in a substrate in which at least a part corresponding to the thin layer is made of silicon, III-V material, SiC, Ge, GaN or a ferroelectric or piezoelectric material, or sapphire.

19. Process to obtain a thin layer, implementing the process for making a removable substrate according to claim 1, and then separating the thin layer from a remaining part of the substrate.

20. Process for obtaining a thin layer according to claim 19, wherein the separating includes at least one of applying a second heat treatment and applying mechanical stresses.

21. Process for obtaining a semiconductor on insulator type structure, implementing the process for making a removable substrate according to claim 17, and then separating the thin layer from a remaining part of the substrate, the stiffener presenting an insulating face to the thin layer, a part of the substrate corresponding to the thin layer being made of a semiconducting material.

22. Process for obtaining a semiconductor on insulator type structure according to claim 21, wherein the part of the substrate corresponding to the thin layer is made of silicon, or a III-V material, or SiC.

23. Process for obtaining a semiconductor on insulator type structure according to claim 21, wherein the separating includes at least one of applying a second heat treatment and applying mechanical stresses.

27. The process according to claim 1, wherein the heat-treating is further configured to evacuate the gaseous species in the weakened zone, so as to allow at least one of an epitaxy process or heteroepitaxy process after the heat treating.

28. The process according to claim 6, wherein conditions of introduction of the gaseous species are such that, in an absence of evacuating the gaseous species from the microcavities, annealing the cavities at 500°

C. would lead to blisters.

29. The process according to claim 6, wherein conditions of introduction of the gaseous species are limit implantation dose conditions which give a fracture at a high temperature.

24. A process for making a thin layer comprising:

introducing a gaseous species into a zone of the substrate to form micro-cavities in the zone, the zone thereby being weakened and delimiting a thin layer with one face of the substrate;

first heat-treating, after said introducing, the zone of the substrate during a given time to thereby evacuate the gaseous species from the micro-cavities without causing a separation in the substrate because a temperature of the first heat treating and the given time being such that a separation of the thin layer from a remaining part of the substrate does not occur during the first heat-treating;

second heat-treating used for technological processing, after said first heat-treating; and

separating, after said second heat-treating, the thin layer from the remaining part of the substrate.

25. The process according to claim 24, wherein the second heat-treating is configured to make at least one of an anti-reflection layer, a ground plane or a controlled doping zone.

26. The process according to claim 24, wherein the second heat-treating is an epitaxy growth process.